Abstracts
2012
Psychological Consequence of Tinnitus and the Meaning of Life
Richard Tyler, PhD
Departments of Otolaryngology and Communicative Sciences and Disorders
University of Iowa
How is your quality of life? Is it better than your neighbors? Is it worse than last year? How would it change if you went deaf, or blind, couldn’t talk, or had tinnitus?
For years people have attempted to measure the quality of life, particularly for allocation of limited health care resources and for compensation to injured workers. There are several ‘validated’ scales. But how do we know if they are really valid? I have been disenchanted with quality of life scales and their application to hearing loss and tinnitus.
I consider the primary problems experienced by tinnitus sufferers include thoughts and emotions, hearing, concentration and sleep. Secondary problems include work and social activities. I will review our development of the Tinnitus Handicap Questionnaire, and a new Tinnitus Activities Questionnaire which uses a 0-100 interval scale. I will contrast this to another scale that uses a three-label category scale. I will share preliminary data from a new ‘Meaning of Life’ questionnaire, and report data from cochlear implant users and those with tinnitus.
Parental Interaction Predicts Vocabulary in Children with Cochlear Implants
Jongmin Jung
Department of Speech, Language, and Hearing Sciences
Purdue University
This investigation sought to identify the parent and child behaviors that predict language outcomes in children with cochlear implants (CIs). Eight children with CIs (all implanted before their third birthday) and their parents participated in the study. Twenty-minute parent-child interactions were collected at 3 months post-CI activation. Four raters assessed interactions watching 2-min video clips. Expressive vocabulary size was collected by using the MacArthur-Bates Communicative Development Inventories (CDIs) at 6, 12, 18, and 24 months post-activation. Stepwise regressions controlling for age at activation indicated that distance between parent and child was as the most concrete and reliable predictor of language outcomes (accounting for more than 70% of the variance in vocabulary). Parent’s sensitivity, reinforcement, clearness of speech, turn-taking, and parent’s affection also appeared as predictors under some rater combinations. Compared to other variables, distance had the greatest potential to facilitate language development of young CI recipients.
The role of intersensory redundancy on infants' perception of social events: Faces and prosody of speech.
Irina Castellanos, PhD
(candidate for postdoctoral fellowship)
Department of Psychology
Florida International University
Social events are fundamental for guiding and shaping infants’ perceptual, cognitive, social, and linguistic development. In this talk, I focus on studies examining infants’ discrimination of faces and prosody of speech, two of the earliest and most salient social properties of stimulation. Typical social interactions are multimodal in nature, however, the majority of research on infants’ discrimination of faces and prosody of speech has been conducted within the context of unimodal (hearing or seeing alone) stimulation. Integrating studies of unimodal functioning with studies of multimodal functioning (concurrently hearing and seeing) provide a more comprehensive understanding of infant attention and development. I present studies examining how infants’ selective attention to faces and prosody of speech changes as a function of multimodal stimulation across exploratory and developmental time. Finally, I discuss how insight into atypical development can be gained through understanding how typical developmental processes come on line.
IC was supported by NIH/NIGMS R25 GM061347.
Context Effects on Pitch Contour Identification in Normal-Hearing Listeners and Cochlear-Implant Users
Xin Luo, PhD
Department of Speech, Language, and Hearing Sciences
Purdue University
Studies have shown that the mean fundamental frequency (F0) of a preceding sentence has a contrastive effect on lexical tone perception in normal-hearing (NH) listeners who speak tonal languages. The context effects may help listeners normalize the pitch variations in lexical tones produced by different talkers. In this study, English-speaking NH listeners and cochlear-implant (CI) users were tested on their abilities to identify flat- and rising-pitch contours with preceding flat-pitch contours. For NH listeners, pitch contours contained either F0 alone or the lowest four harmonics with the F0 ranging from 160 to 200 Hz. For CI users, pitch contours with the lowest four harmonics were presented via their clinical speech processors; an extended F0 range (100-300 Hz) was used to accommodate the poor pitch perception with CI. The results showed that for most NH and CI subjects, the F0 of preceding context had a contrastive effect on pitch contour identification (PCI), i.e., pitch contours were more likely to be identified as rising when the preceding context had a higher F0. The observed context effects were similar to those in lexical tone perception, although the target stimuli were not lexically meaningful, the context stimuli were only 500 ms long, and the subjects had no tonal language experience. The similar results in NH listeners and CI users suggest that the context effects were due to central auditory processing, regardless of the various peripheral auditory inputs. To better understand the underlying mechanisms, context effects on PCI were also tested in CI users via direct electric stimulation, using both place and temporal coding. Place-pitch contours were created by steering current between two adjacent apical electrodes, while temporal-pitch contours were created by varying amplitude-modulation frequencies (100-300 Hz). However, initial results of direct electric stimulation did not show consistent context effects and further investigation is warranted.
Is the child's brain "primed" to learn? Developmental constraints on sequential learning and language as revealed by event-related brain potentials
Christopher M. Conway, PhD
Department of Psychology
Saint Louis University
Human development is characterized by a period of relative immaturity in cognitive, perceptual and motor systems, during which environmental exposure to particular inputs is key. For instance, evidence suggests that children must be exposed to language within a particular critical or sensitive period in order for acquisition to occur optimally (Lenneberg, 1967; Newport, 1990). However, it is not entirely clear whether such sensitive periods are specific to language or are due to global constraints on the development of domain-general learning processes. One way to tease apart the domain-specific versus domain-general nature of sensitive periods is by investigating the development of non-linguistic, domain-general learning abilities, such as sequential learning. Sequential learning refers to the automatic, incidental, and effortless acquisition of statistical patterns in the environment that generally results in knowledge that is difficult to express verbally (Cleeremans, Destrebecqz, & Boyer, 1998; Conway, Bauernschmidt, Huang, & Pisoni, 2010; Perruchet & Pacton, 2006). Although sequential learning is believed to play an important role in language learning (Conway et al., 2010; Misyak, Christiansen, & Tomblin, 2010; Saffran, 2003; Shafto et al., in press), few studies have probed the neural mechanisms mediating sequential learning in children, making it difficult to specify its neurocognitive development. In the current talk I will present initial evidence from two event-related potential (ERP) studies suggesting that 1) the neural mechanisms underlying non-linguistic, visual sequential learning are partly co-extensive with mechanisms underlying language processing in typically-developing adults; 2) the brain mechanisms mediating sequential learning appear to be more efficient in young children (age 6-9 and 9-12 years) compared to adults. These findings suggest that the child’s brain is “primed” to learn environmental patterns, which provides an alternative conceptualization for the nature of sensitive periods in language development by focusing on domain-general learning constraints. Additional work will be described that is currently investigating whether deaf children with cochlear implants display an altered neural profile for sequential learning, which may help to account for difficulties in their spoken language development.
2011
Hearing Loss: From Detection to Diagnosis
Luis F. Escobar, MD, MS.
Medical Director
Medical Genetics & Newborn Follow up
St. Vincent Hospital & Health Services Indianapolis
We will review the current approach to hearing loss in the newborn and the ramifications for follow up. Although, hearing is the main goal and concern, we may be missing situations in which patients may have a progressive hearing loss or an underlying genetic disorder.
Clinical Trials and Tribulations: Navigating Regulatory Mazes Toward FDA Approval of Earlier Cochlear Implantation
Jennifer Phan, MD, Derek Houston, PhD, Chad Ruffin, MD, & Richard Miyamoto, MD
Department of Otolaryngology – Head & Neck Surgery
Indiana University School of Medicine
The U.S. Food and Drug Administration (FDA) approves cochlear implantation for children with profound bilateral sensorineural hearing loss who are at least 12 months old. Before that age, typically hearing infants acquire remarkable language skills, and small-scale studies with deaf children implanted before 12 months suggest that very early implantation increases the chances of age-appropriate language outcomes. Earlier implantation can be performed "off-label," but insurance companies will often deny coverage until after the FDA-recommended 12 months. In this presentation, we will discuss our plan to conduct a larger-scale, NIH-funded clinical trial with the goal of contributing valuable information about the effects of cochlear implantation before 12 months of age and, depending on the results, possibly leading to a lowering of the FDA age minimum to 6 months. As one might expect, navigating such a study with said goal through the FDA, NIH, and IU's IRB procedures and regulations is complex and challenging. Much of this presentation will focus on what we have learned so far about the procedures and how they relate to each other. We will allow ample time for input and discussion of both the procedural and scientific aspects of this project.
November 9, 2011
12pm
Cochlear Implants - Past, Present and Future
Richard T. Miyamoto, MD
Arilla Spence DeVault Professor and Chairman
Department of Otolaryngology-Head and Neck Surgery
Indiana University School of Medicine
Causality and cross-modal integration: Theoretical findings and clinical applications
Michael Schutz, PhD
Music, Acoustics, Perception and LEarning (MAPLE) lab
McMaster University School of the Arts
My colleagues and I have documented a musical illusion in which percussionists are able to manipulate an audience’s perception of note duration independent of that note’s acoustic properties. Curiously, this illusion is at odds with previous research and current theoretical models of auditory-visual integration. Recent work has shown the perception of a causal, cross-modal link plays a key role in the explaining this exception. For example, impact motions integrate with sounds caused by impact events (such as the sound of a percussion instrument being struck), but not sounds that are produced by different types of events (such as air moving over a reed in the case of a clarinet). This talk will summarize some of my work on this illusion as well as unpublished data exploring the role of amplitude envelope (the shape of a sound over time) in audio-visual integration.
Additionally, I will discuss some new experiments exploring clinical applications of this illusion amongst children with autism, as well as older adults suffering from hearing impairment. For a demonstration of the illusion, please see a brief (2 min) TV segment now posted online at http://www.maplelab.net/press-room
Lexical and semantic development in children with cochlear implants.
Ulrika Löfkvist
Speech Language Pathologist (SLP)
LSLS Cert. AVEd, PhD-Student
Cochlear Implant Section
Karolinska University Hospital
The purpose of the PhD-project is to study lexical and semantic development in children with cochlear implants and how the lexical and semantic ability is related to cognitive function and verbal stimulation from their parents. The emphasis of the presentation will be on the results from the first study:
I)Word fluency performance and strategies in children with cochlear implants: Age-dependent effects? (manuscript in preparation).
II) Lexical and semantic development in younger school children with CI compared to age-matched normal hearing children (manuscript in preparation).
Bilateral Cochlear Implantation in Children
Ruth Litovsky , PhD
Associate Professor
Department of Communicative Disorders
Waisman Center
University of Wisconsin - Madison
Cochlear implants (CIs) are being provided to young children at an increasing rate. Many of these children attain spoken language skills that are well within the range of performance seen in normal-hearing peers. This work will be reviewed, along with evidence to suggest that there is a gap in performance between the CI users and NH children. The reasons for this gap are not well understood, but contributing factors will be discussed. One contributing factor is the fact that most CI users are implanted in a single ear; however, having access to inputs in both ears facilitates listeners’ abilities to utilize auditory cues. There is a growing population of children who are receiving bilateral cochlear implants (BiCIs), and outcomes in those children suggest that their ability to hear speech in noise, and to orient in their environment, is significantly better with bilateral vs. unilateral CIs. An important caveat is that, still in this population, many children do not perform at the same level as their normal-hearing (NH) peers. Results will be presented in which children with CIs are compared with NH children who have the same chronological age, or same amount of hearing experience (hearing age). In addition, data will be considered within the context of evidence from studies in adult listeners, suggesting that bilateral CIs do not provide binaural cues with fidelity. The stimuli at the two ears are unlikely to be place-matched (frequency-matched) or loudness balanced; there are likely to be asymmetries in neural survival and dynamic range, as well as compression due to unmatched microphone settings. In addition, current spread, leading to electrode interaction effects may cause blurring of binaural signals. Our studies with adult listeners demonstrate that if binaural cues can be restored and introduced to listeners through research processors, there is a greater likelihood that the gap in performance can be minimized. The potential role of binaural cue restoration in the development of spatial hearing skills of children will be discussed. Work supported by NIH-NIDCD
Nonverbal Cognitive Skills in Deaf Infants
Carissa Shafto
Dept. of Psychological & Brain Sciences
University of Louisville
Recent studies suggest that deafness can affect not only speech and language development but also general cognitive skills. In particular, there is evidence that deaf children differ in their visual attention and other nonverbal cognitive abilities compared to children with normal hearing (e.g., Marschark & Hauser, 2008; Mitchell & Quittner, 1996; Pisoni, 2008), but little is known about when these differences might emerge. I will present results from two studies comparing the nonverbal cognitive abilities of deaf infants (aged 4 to 23 months) to age-matched infants with normal hearing: a completed study of visual attention and encoding ability (Study 1) and an ongoing study of visual sequence learning ability (Study 2). I will discuss some potential explanations for differences in nonverbal cognitive.
Visuospatial sequence training with children who are deaf or hard of hearing
Michelle Gremp, PhD, CED
Education Coordinator, CID
Practicum Supervisor
Washington University School of Medicine
Program in Audiology and Communication Sciences
Despite advances in hearing aid and cochlear implant technologies, many children who are deaf or hard of hearing continue to lag behind typically hearing peers in language and reading abilities. Additionally, there is a high degree of variability in language outcomes among children with a hearing loss. Evidence indicates that auditory input provides a foundation not only for speech and language development but for cognitive functions such as sequence memory and learning ability. This study investigated a variety of cognitive functions with two major aims in mind: 1) to verify differences between children who are deaf or hard of hearing and typically hearing children on a variety of cognitive tasks, 2) to determine if visuospatial sequencing practice would result in improvements on nontrained tasks measuring phonological memory, sequencing ability, and executive function. Children who were deaf or hard of hearing as well as children with typical hearing participated in 10 days of visuospatial sequence practice as part of this study. One pretraining and two post training sessions assessed cognitive tasks involving visuospatial short-term memory; verbal short-term memory (nonword repetition); inhibition; and visual sequence learning. Pretraining assessments revealed significant differences between the groups on verbal tasks with both auditory and visual stimuli as well as on tasks of inhibition and visual sequencing. In addition, differences were revealed on visual tasks with nonverbal stimuli. These findings suggest a general difference or delay in performance beyond the anticipated verbal delay related to a deficit in hearing acuity. Two post training assessment sessions revealed improvement on the nonword repetition task for the adaptive group following the sequencing practice. These findings suggest that visuospatial sequencing practice can lead to improvements in language abilities. Possible applications and important next steps will also be discussed.
The Development of Novel Perceptually Robust Tests of Speech Perception: Some Preliminary Findings with PRESTO
David B. Pisoni, Jaimie L. Gilbert and Terrin N. Tamati
Department of Psychological and Brain Sciences
Speech Research Laboratory
Indiana University, Bloomington
For the last several years, we have been working on the development of a fundamentally new class of speech recognition tests for both basic and clinical use. We call these new tests "perceptually robust tests" because they are designed to be ecologically valid assessments of the core underlying elementary information processing skills that are used by listeners in everyday real-world listening environments. All current clinical tests of speech recognition use only a single talker or a very small number of talkers who produce isolated words or sentences that are highly constrained in terms of word frequency, neighborhood density, syntax, sentence length and semantic coherence. In this presentation, we report some preliminary results on a new test called PRESTO which was specifically designed at the outset to include a great deal of variability of the kind that a typical listener might encounter in everyday activities. These sources of variability include speech samples from multiple talkers who come from different dialect regions in the US as well as a range of sentence structures, lengths and topics. Our results suggest that investigation of variability in both the stimulus materials and the listeners can provide new insights into individual differences and variability in speech recognition in adverse listening conditions.
Working Memory Training for Children with Cochlear Implants: What Does It Do?
William G. Kronenberger, PhD
Associate Professor
Director, Section of Psychology
Department of Psychiatry
Indiana University School of Medicine
Riley Child and Adolescent Psychiatry Clinic
Working memory is critical for cognitive information processing because it provides short-term storage for information that is the focus of immediate attention and controlled processing. Prior research has demonstrated that, on average, children with cochlear implants have smaller working memory capacity than normal hearing children, especially for phonological-verbal information. Furthermore, CI users with longer verbal working memory spans demonstrate better performance on a range of spoken word recognition and higher-order language tasks.
Recent research suggests that working memory capacity is not a fixed ability but may be improved with training. Some computer-based working memory training programs have produced change in working memory, attention, and executive functioning in normal hearing children with low working memory capacity. However, no research has specifically investigated working memory training in a sample of children with cochlear implants. Working memory training for children with CIs offers the potential to target this known neurocognitive risk area, which has been demonstrated to predict speech and language outcomes.
We investigated whether an established (for normal hearing children) working memory training program (Cogmed RM) could be applied to children with cochlear implants. A sample of 9 deaf children (7-15 years of age) with CIs completed the 5 week (5 days per week, 30-40 minutes per day) computer-based Cogmed RM working memory training program at home. Measures of feasibility and efficacy were obtained at two time points prior to working memory training (at the beginning and end of a waiting period), immediately after training, and at 1 month and 6 months after training.
As expected, the sample showed no change on almost all measures during the waiting period of no intervention. In contrast, the sample showed significant improvement on neurocognitive measures of working memory, parent-reported working memory behavior, and sentence repetition skills after completion of working memory training. The magnitude of gains in working memory declined at 1 and 6 month follow up assessments, but sentence repetition improvement remained at 6 month follow-up assessment.
Results demonstrate that working memory training is feasible and may produce benefit in some memory and language skills for children with CIs. Randomized, controlled, blinded trials of working memory training in children with CIs are an important next step in investigating the efficacy and clinical value of this novel intervention.
Using an Auditory Spoken Language Matrix Assessment for Children with Cochlear Implants from Spanish-Speaking Homes
Christine Yoshinaga-Itano, PhD, CCC-A
Department of Speech, Language, and Hearing Sciences
University of Colorado, Boulder
This presentation will discuss the use of new assessment tools and technological advances in the differential diagnosis of auditory/language/speech development of children who are deaf or hard of hearing. It has been particularly beneficial for children from Spanish speaking home who have received cochlear implants. The Matrix includes: audibility assurance, auditory prelinguistic discrimination, auditory skill development, vocal development, and language development.
Cochlear Implants and Additional Disabilities, approaches to this group of children
Susan Wiley, MD
Developmental Pediatrician
Fellowship Director
Cincinnati Children's Hospital Medical Center
Adjunct Associate Professor
University of Cincinnati College of Medicine
This presentation will attempt to address clinical and research implications of children with implants who have additional disabilities. Research considerations regarding categorization of children as it relates to outcome measures will be discussed as well as a variety of outcome measures that may be appropriate for this complex group of children, such as qualitative information, functional outcomes, and effectiveness of interventions/therapy strategies.
Infant language learning from multimodal speech cues
Alexa Romberg
Department of Psychology and Waisman Center
University of Wisconsin - Madison
During the first year of life, human infants readily absorb a staggering amount of information from their environment. My work has focused on how infants use this information in real time to anticipate downstream events, demonstrating that the predictability of cues within an event stream influences how infants attend to and anticipate future events. Undoubtedly, one of the most pervasive aspects of the environment is language and an extensive body of work has shown that infants are sensitive to regularities in this language environment. The experiments that have explored infants’ early language learning abilities have used primarily auditory stimuli, generally playing the language samples over speakers in a sound-proof booth. However, the cues that make language predictable do not only exist in the auditory modality, but also in the visual – the dynamics of the talking face provide many cues to language structure and function that are highly correlated with the auditory stream. The present work investigates how 8- and 12-month-old infants attend to and use these multimodal regularities in a language learning task. The results reveal significant differences between age groups and between individual infants in attention to and learning from these multimodal cues.
Working with Bilingual CI Children and Families
Amy McConkey Robbins, MS, CCC-SLP
Communication Consulting Services
The unique challenges of clinical work with this population will be reviewed, along with a suggested approach to particularly complex families. Encouraging findings on multilingual proficiency in a subgroup of this population will be presented. Guidelines for managing children with cochlear implants who are learning multiple languages will be provided, supported by published research, or in some cases, clinical experience. The importance of the "mother tongue" as an essential part of parent/infant bonding will be reinforced.
Not-so-terrible twos: Assessing speech-sound discrimination in toddlers
Rachael Frush Holt, Ph.D., CCC (Audiology)
Department of Speech and Hearing Sciences
Indiana University
Evaluating benefit from sensory aids in children is in the interest of many parties – the children themselves, parents/caregivers, clinicians, scientists, teachers, and third-party payers, to name a few. Although many different outcome measures are ripe for evaluating benefit, one of the most fundamental domains that sensory aids are intended to address is that of speech perception. The procedures available to clinicians for assessing speech perception are limited primarily by the inherent changes in children’s development. Some procedures, such as spoken word recognition testing, only are appropriate for children with a command of oral language; others, such as the conditioned head turn response, only are appropriate for infants. One population for whom we lack reliable speech perception assessments is toddlers. This has led to gaps in knowledge of how speech perception develops during this critical age when vocabulary is expanding rapidly. The dearth of speech perception assessment procedures for toddlers also has resulted in suboptimal clinical tools for evaluating benefit from sensory aids and for guiding intervention decisions for this population. The objective of this research is to develop further a procedure for assessing speech discrimination in toddlers as young as 2 years of age. A series of modifications were made to the Change/No-Change procedure (Sussman & Carney, 1989) that were intended to make it a viable method for testing toddlers. The modified procedure was used to evaluate discrimination of perceptually easy and hard speech-sound contrasts in 2- and 3-year-old normal-hearing, typically developing children. The results suggest that the modifications allow for reliable testing of children as young as 2.5-years-old. However, further work is needed for testing of the youngest 2-year-olds. Refining this procedure will allow further exploration of speech-sound processing in typically developing children and in those with hearing loss, who are believed to have a core deficit in phonological encoding. It also potentially will provide audiologists a tool for evaluating benefit from hearing aids and cochlear implants in children at an age when decisions regarding appropriate intervention are critical for future language development.
[Research supported by Indiana University’s Faculty Research Support Program]
2010
The article paradigm in Spanish-speaking children with SLI in language contact situations
Raquel T Anderson, PhD, CCC-SLP
Associate Professor
Department of Speech and Hearing Sciences
Bilingual Language Laboratory
Indiana University Bloomington
During the past two decades, there has been an increase in the cross-linguistic study of language impairment in children. This research has provided important information on the patterns of skill and disability that has helped both clinicians and researchers. For clinicians, it has provided data on how language impairment is manifested in children. In this manner, better assessment and intervention strategies can be incorporated into clinical practice with children who speak a variety of languages. For researchers interested in explaining the factors that give rise to impairment, it has provided necessary data for testing the various theoretical models that have been proposed to explain the disability. Most of the research with Spanish-speaking children has focused on studying children who are either monolingual speakers or incipient (beginning) second language (i.e. English) learners. In incipient speakers, the data pertain to children‚s performance at a specific point in time, with no follow-up of potential changes in skill in Spanish across time, as these were acquiring English. The purpose of the present study was to obtain initial data on Spanish-speaking children with language impairment who were in a language contact situation (English-Spanish) to assess their native language skills across time and to evaluate the potential impact that language contact may have on their Spanish language skills. The specific focus of the research was on the children‚s use of the article paradigm, as this grammatical aspect has been reported as problematic in children with language impairment as well as in individuals in language contact situations. We followed sixteen Spanish-speaking children in an English immersion context for a period of three years, four of whom with diagnosed with language impairment (specific language impairment). Data were collected annually via both experimental procedures and spontaneous speech. Results suggest a different trend in the use of Spanish article in children with typical language skills and children with specific language impairment, suggesting that inherent language skill and sociolinguistic context may impact children‚s use and maintenance of skill with respect to the Spanish article system. Theoretical and clinical implications will be presented, as well as research needs in the area of child language disorders and bilingualism.
Identifying perceptual correlates of speech in noise in order to improve recognition
Mandy Anaya
Graduate Student
Department of Psychological & Brain Sciences
Speech Research Laboratory
Indiana University Bloomington
Recognizing speech in noise requires a complex set of perceptual and cognitive skills. While typically developing individuals seem to recognize speech in noise with little effort, some clinical populations such as individuals with cochlear implants (CI) struggle with this task. It remains unclear why CI users experience such a large deficit when trying to recognize speech in adverse listening conditions. Recent findings in other language-impaired populations have provided some possible explanations. Dyslexics and individuals with specific language impairment exhibit difficulties in processing amplitude envelope rise time and sound duration, stimulus features that are important for perceiving speech rhythm. The language deficits in these populations appear to stem in part from a speech segmentation deficit which revents the formation of robust phonological representations during development. We hypothesize a similar deficit in CI users who are not exposed to native speech prosody early in life. We further hypothesize that these deficits in language acquisition correlate with diminished top-down connections, weakening CI users' ability to utilize stimulus regularities that are important for segregating auditory streams. The research proposed here will test these hypotheses by examining how CI users' basic auditory processing skills and cognitive abilities relate to their ability to recognize speech in noise. Possible use of these measures to improve speech in noise recognition for CI users will be discussed.
How infants learn the sound structure of language
Elizabeth Johnson, PhD
Department of Psychology
University of Toronto at Mississauga
Many contemporary models of language acquisition are built upon the assumption that infants possess sophisticated statistical learning abilities that allow them to induce the sound structure of their native language just by listening to the patterning of speech sounds in their environment. Simple meaningless patterned speech stimuli, often referred to as artificial languages by psychologists and linguists, provide the strongest evidence for this view. In dozens of groundbreaking studies, infants have been shown to use statistical cues alone to successfully extract word boundaries and grammatical rules from these simplified made up artificial languages. In this presentation, I will discuss both the strengths and weaknesses of artificial language research. I will conclude that although artificial languages represent an important tool in the study of language acquisition, over-reliance on this experimental methodology can lead to a distorted outlook on early language acquisition.
Early Hearing Detection and Intervention in Indiana: Program, Progress, and Possibilities
Gayla Hutsell Guignard
Indiana EHDI Program Director
Indiana State Department of Health
Julie Schulte
Indiana EHDI Follow-up Coordinator
Indiana State Department of Health
Early Hearing Detection and Intervention (EHDI) programs across America have been given a clear charge-- to ensure the three primary components of EHDI are secured for children born in this country: 1) screening of hearing prior to hospital discharge, 2) diagnosis of hearing loss before age 3 months, and 3) enrollment in early intervention prior to six months of age. The mandate for Universal Newborn Hearing Screening (UNHS) was passed in 1999 with all Indiana birthing hospitals establishing and implementing a UNHS program by July, 2000. Since that time, the EHDI program at the Indiana State Department has provided monitoring, surveillance, technical support and direct assistance to hospitals, birthing facilities, families, and professionals across the state. This presentation will cover a brief program overview including the components of early hearing detection and intervention, sharing of EHDI data and observed trends, information about the EHDI Alert Response System (EARS) data management tool, and the results of a recent project which incorporated the Plan-Do-Study-Act (PDSA) model through an Indiana collaboration in the National Initiative for Children’s Health Care Quality (NICHQ).
Spoken Language Processing and Spatial Hearing in 2-Year-Old Children Who Use Cochlear Implants
Tina Grieco-Calub, PhD, CCC-A
Assistant Professor
Audiology
Allied Health & Communicative Disorders
Northern Illinois University
College of Health & Human Services
Cochlear implants (CIs) can promote the development of various auditory skills including spoken language in young children with prelingual deafness. In addition, better binaural skills (i.e., speech recognition in the presence of acoustic competition and spatial hearing skills such as sound localization) tend to be more mature when children are provided with bilateral cochlear implants (i.e., one for each ear). In general, better outcomes have been achieved with earlier ages of implantation. There is, however, large individual variability in performance, and the source of that variability is poorly understood. In addition, because outcomes have been traditionally documented with standardized measures, little is known about how these skills develop in children who use CIs at ages when these skills are beginning to emerge. Since implantation often occurs by 1 year of age, there is an opportunity to investigate the dynamic process of language acquisition as well as the development of other auditory skills using well-established behavioral methods designed for children under the age of 3 years. The series of experiments that will be presented will explore two auditory skills that emerge at young ages: spoken language processing and spatial hearing. Participants included children who were 2 years of age who used either unilateral or bilateral CIs and age-matched children with normal acoustic hearing. Spoken language processing was evaluated using the “looking-while-listening” method and spatial hearing was evaluated with the right-left discrimination task using an observer-based psychophysical procedure. Discussion will include the advantage of these methodologies to evaluate auditory and language skills in young implant users, possible sources of the individual variability in performance with CIs, and additional ways in which behavioral techniques can be used to study early language abilities in young children who use CIs.
A role for declarative and procedural memory in normal and disordered language
Michael Ullman, PhD
Professor
Brain and Language Lab
Department of Neuroscience
Georgetown University
Increasing evidence suggests that language crucially depends on two long-term memory brain systems, declarative memory and procedural memory. Because the computational, anatomical, physiological, cellular, molecular and genetic substrates of these two systems are quite well-studied, in both animals and humans, they lead to specific predictions about language that would not likely be made in the more circumscribed study of language alone.This approach is thus very powerful in being able to generate a wide range of new predictions for language. I will first give some background on the two memory systems, then discuss the manner in which language is predicted to depend on them. One of the key concepts is that to some extent the two systems can subserve the same functions (e.g., for navigation, grammar, etc.), and thus they play redundant roles for these functions. This has a variety of important consequences for normal and disordered language and other cognitive domains. I will then present evidence that basic aspects of language do indeed depend on the two memory systems, though in different ways across different unimpaired and impaired populations. We will discuss normal first and second language, individual and group differences (sex and handedness differences), and a variety of developmental disorders (e.g., Specific Language Impairment, autism and Tourette syndrome).
The Origins of Domain-specificity in Auditory Pattern Learning
Erin Hannon, PhD
Assistant Professor
Department of Psychology
University of Nevada, Las Vegas
Music and speech are both complex sound structures that unfold over time, yet they undoubtedly rely on fundamentally dissimilar perceptual processes and knowledge. Given that naïve infant listeners must discover and learn meaningful structures in music and speech in parallel, a natural question to ask is whether early auditory learning is influenced by domain-specific or domain-general constraints. I will describe two sets of experiments that explore and compare how infants, children, and adults respond to speech-music similarities and dissimilarities. Because music and speech share certain rhythmic properties, one set of experiments explores the extent to which listeners can classify French and English speech and music stimuli on the basis of rhythm. Experiments examine listeners’ classification of songs and speech utterances after familiarization to other stimuli within the same domain or across domain (e.g. classification of songs after familiarization to speech and vice versa). A second set of experiments examines whether or not infants and adults exhibit domain-specific biases when they attempt to infer rule-like patterns from sound sequences in a linguistic versus musical context (e.g. rules based on syllables/timbres vs. melody). Results across both sets of experiments suggest that auditory pattern processing is increasingly influenced by domain-specific knowledge over the course of development.
Hearing in Noise, Can music training help?
Nina Kraus, PhD
Hugh Knowles Professor, Northwestern University
Communication Sciences, Neurobiology & Physiology; Otolaryngology
Our sensory systems are primed to recognize regularities in the soundscape – for example the sound patterns that distinguish your friend’s voice from other sounds in a noisy restaurant. Musical experience has a profound effect on the nervous system. It is not a simple gain effect; rather, musical experiences the sensory function in “smart” ways, selectively enhancing sound patterns and meaningful acoustic elements. We can measure brain responses that reflect the acoustic properties of sound with sub-millisecond precision. The neural activity physically resembles the sound waves, enabling us to determine the fidelity with which acoustic elements like pitch, timing and timbre are transcribed by the nervous system. Musicians develop the ability to hear relevant signals embedded in a network of melodies and harmonies. This ability transfers to hearing a target speaker’s voice in background noise. We are beginning to understand a sliver of the biological basis for this perceptual advantage (1,2) and its counterpart in clinical populations with excessive difficulty hearing in noise. Objective neural signatures –from the human auditory brainstem- reflect a notable portion of the variance in the multi-faceted task of hearing in noise (1,3). Effective use of sound patterns by the nervous system is likely mediated by cognitive processes such as attention and memory through the corticofugal network. (4) Active engagement with music confers advantages in the neural processing and perception of sounds important for everyday listening tasks. (5)
1. Chandrasekaran et al. 2009, Neuron 64:311-319.
2. Parbery-Clark et al. 2009, J Neuroscience 29:14100 - 14107.
3. Hornickel et al. 2009 PNAS 31: 13022–13027.
4. Tzounopoulos and Kraus 2009, Neuron 62: 463-469.
5. Chandrasekaran and Kraus 2010, Music Perception 27:297-306.
see http://www.brainvolts.northwestern.edu (start with the slide show ‘neural encoding of music’)
Using Speech Recognition Technology to Automatically Analyze the Natural Language Environment of Young Children
Jill Gilkerson, PhD
Director of Child Language Research
LENA Foundation
New technology allows for day-long audio recordings of a child’s natural language environment and uses speech recognition technology to automatically analyze the audio. Children ages 2 months – 48 months wear a digital recorder that continuously captures their vocal output and what is spoken around them during a 16-hour day. Automatic processing produces hourly information focusing on: 1) adult word counts, 2) conversational turns (between adult and child), and 3) child vocalization frequency. This presentation provides an overview of the technology as well as resulting information on natural language environments, including a discussion of results from three independent samples: a group of typically developing children (N=329), a group of children with developmental delays (N=34), and a group of children with Autism Spectrum Disorder (N=34). Clinical and research implications for the deaf and hard of hearing community will be discussed.
Genetics of hearing loss: "Can you hear me now?"
Luis F. Escobar, MD, MS
Medical Director
Medical Genetics & Newborn Follow up
Staff neonatologist
St. Vincent Children's Hospital
The talk is intended to briefly review hearing loss as human variation and diversity. It suggests that variations in human morphology and functioning cause disability according to each patient's environment. The audience should be able to recognize the genetic perspective in the diagnosis of hearing loss and how that may influence treatment in individual situations. A review of few dysmorphologic conditions involved in hearing deficits will be presented.
2009
Developmental Outcomes for Young Children with Hearing Loss
Susan Nittrouer, PhD
Professor and Director of Research
Department of Otolaryngology
The Ohio State University
The past couple decades have brought unprecedented improvements in how we treat young children with severe-to-profound hearing loss (HL). Nonetheless, not all children are faring as well as we would like them to. This presentation will report data from a five-year studying following children with and without HL from 12 to 48 months of age. Developmental measures made every six months traced changes in these children’s language and psychosocial skills. Data collected regarding a variety of independent variables provided information that could be used to assess the factors that accounted for variance among children in these developmental outcomes. Results provide clues for how we might modify clinical interventions to help close the remaining gap between developmental outcomes for children with and without HL.
Phantom Sound of Tinnitus: Human Brain Imaging, Animal Models, and Brain Changes from Hearing Loss
Richard Salvi, PhD
Center for Hearing & Deafness
University at Buffalo
The phantom sound of tinnitus was once believed to originate in the inner ear; however, recent evidence suggests that tinnitus originates in the brain. To test this hypothesis, we used positron emission tomography (PET) to image brain activity in tinnitus subjects that could modulate the loudness of their tinnitus with an oral facial movement (OFM), lateral eye-gaze or intravenous lidocaine treatment. The results from this series of studies showed that the pattern of brain activity associated with tinnitus was fundamentally different from that evoked by a real sound presented to the ear. These results suggested that the neural generators for tinnitus reside in the central nervous system and involve both auditory and non-auditory sites such as the hippocampus. To gain insights into the biological bases of tinnitus, we developed animal models capable of “telling us” if they were experiencing tinnitus. We used these behavioral models to determine if drugs targeting NMDA receptor, cholinergic receptors or potassium channels could suppress tinnitus; only the potassium channel modulator suppressed tinnitus in a dose-dependent manner. Previous neurophysiological models of debilitating tinnitus assume that non-auditory structures such as the hippocampus contribute to the severity of tinnitus by linking memories of the phantom sound to emotion. The formation of new memories may be related to the high rate of neurogenesis in the hippocampus. To determine if hippocampal neurogenesis might be altered by inner ear damage that induces tinnitus, we unilateral exposed rats to intense noise that deafened one ear. Surprisingly, hippocampal neurogenesis was greatly suppressed and the acquisition of new memories was impaired. Tinnitus was once considered a difficult, if not impossible phenomenon to study, but recent advances in human brain imaging and the development of animal models have greatly advanced our understanding of tinnitus.
Phonological Awareness Skills of Children with Cochlear Implants
Sophie E. Ambrose
Children's Auditory Research and Evaluation Center
House Ear Institute
We have completed two studies examining the phonological awareness abilities of children who are deaf and utilize cochlear implants. The first study examined relationships between early child and parental factors and later phonological awareness and reading skills of young children with cochlear implants. The purpose of this longitudinal study was to examine the unique contributions of children's early language skills and mothers' facilitative language techniques during storybook reading on later literacy skills in a group of young deaf children with cochlear implants. The second study examined the phonological awareness abilities and several related phonological and linguistic skills of preschool children with cochlear implants and a group of children with normal hearing. The purpose of this later study was to determine whether these skills were developing at an age-appropriate pace and to examine which of these factors contributed uniquely to variance in phonological awareness abilities. Results from both studies will be presented and discussed.
Ways with Words: Identifying Factors that Influence Word Learning in Children with Hearing Loss
Mary Pat Moeller, PhD
Director, Center for Childhood Deafness
Lied Learning and Technology Center at
Boys Town National Research Hospital
This presentation will examine factors that may influence word learning in infants and young children with normal and impaired hearing, drawing on results from cross sectional and longitudinal studies. Vocabulary development is sometimes thought of as the “number of words” the infant is able to understand or produce at a given time. While important, this number tells us little about the processes (involving social, linguistic and cognitive abilities) that children use as they learn words, or the strategies parents may use to facilitate learning. Results from two current studies will be featured during this presentation: 1) Children’s novel word learning through direct and incidental routes, and 2) Mothers’ conversational responses to young children’s word approximations. Implications for habilitation and future research will be described.
Discovering Sensorimotor Dynamics in Child-Parent Social Interaction and Word Learning
Chen Yu, PhD
Assistant Professor of Psychology
Department of Psychology
Indiana University
Toddlers learn words through millisecond by millisecond, second by second, and minute by minute events that are generated by actively engaging in the world, with objects, and with their social partners who offer object names, gestures and actions. There have been many studies focusing on documenting developmental progresses in early language acquisition and most theories of learning derived from those studies have focused on macro level descriptions and folk-psychological constructs. But very little is known about how any of this works in real time and in the cluttered context of the real world interactions of toddlers and parents, contexts typically characterized by many interesting objects, many shifts in attention by each participant, and many goals (beyond teaching and learning words). This talk will present a series of experiments that provides a systematic study of child-parent interaction and learning as coupled complex systems. Each moment of perceptual and motor activities by the learner determines the next – a head turn determines what is seen next which may determine what is reached for and brought close to the eyes which selects and generates the next view. Our study measures the dynamic multimodal behavioral patterns within and across social partners as children and parents actively engage with and talk about objects in everyday contexts. The project has collected a huge amount of multiple streams of high-resolution high-quality video and speech data from both participants. We have developed and employed various data analysis, data mining and data visualization techniques to discover meaningful patterns from such dense and rich streams of multimodal data. In this way, our research quantifies fine-grained behaviroal patterns within an individual’s cognitive, perceptual and motor systems and across social partners, which brings new insights into cognitive mechanisms underlying real–time learning.
Toward an Attention-Competition Model of Temperament-Language Relationships
Wallace E. Dixon, Jr, PhD
Chair & Professor of Psychology
Department of Psychology
East Tennessee State University
That infants’ and toddlers’ language development is related to dimensions of their temperament is now well established. Which specific dimensions of temperament associate with language depends on the measurements employed; but in general large vocabularies are associated with high scores on attentional control, positive affect, and soothability, and with low scores on negative affect and sensitivity to environmental stimuli. The other side of this coin is that children with difficult temperaments tend to experience language delay. A theoretical framework would help in understanding why temperament and language are correlated, as well as in conceptualizing the social, pragmatic, educational, and clinical implications such correlations entail. A guiding theory could explain why infants and toddlers with difficult temperaments, and with language delay, are also at risk for emotional and behavior disorders in later childhood. Hence, we need a theory to generate both “bench” research questions, such as under what conditions do temperament-language relationships hold; and translational, or “bedside,” research questions, such as can temperamental or language-related interventions reduce the incidence of emotional and behavior disorders. The purpose of this paper is to present a hybrid model which draws on key elements from extant models to 1) explain why temperament and language are correlated, 2) generate testable hypotheses regarding the conditions under which temperament-language relationships hold, and 3) embed temperament-language correlations within an overarching developmental processes model in which attention regulation plays a foundational role in moderating cognitive and emotional functioning.
Predictors of Language Outcomes in Deaf Infants with Cochlear Implants: Implications forIntervention Strategies
Derek Houston, PhD
Department of Otolaryngology - Head & Neck Surgery
Indiana University School of Medicine
Discovering early predictors of language outcomes is key to identifying deaf children who are at risk for poor language outcomes after cochlear implantation. In this talk, I will first review investigations from the Infant Language Lab that have found links between early cognitive and linguistic skills and later language outcomes in both deaf and normal-hearing infants. I will then propose how discovering predictors of language outcomes during infancy can potentially help clinicians target potential language problems more proactively than is currently possible. Finally, I will discuss some future directions that will move us closer toward translating infant assessment methodologies into clinically valuable tools for language habilitation.
Influence of language experience on pitch processing in the human brainstem
Ananthanarayan Krishnan, Ph.D.
Auditory Electrophysiology Laboratory
Department of Speech Language Hearing Sciences
Purdue University, West Lafayette, IN
Historically, the brainstem has been neglected as a part of the brain involved in language processing. We review recent evidence of language-dependent effects in pitch processing based on comparisons of native vs. nonnative speakers of a tonal language from electrophysiological recordings in the auditory brainstem. We argue that there is enhancing of linguistically-relevant pitch dimensions or features well before the auditory signal reaches the cerebral cortex. We propose that long-term experience with a tone language sharpens the tuning characteristics of neurons along the pitch axis with enhanced sensitivity to linguistically relevant, rapidly changing sections of pitch contours. Though not specific to a speech context, experience-dependent brainstem mechanisms for pitch representation are clearly sensitive to particular aspects of pitch contours that native speakers of a tone language have been exposed to. Such experience-dependent effects on lower-level sensory processing are compatible with more integrated, hierarchically organized pathways to language and the brain.
Exploration of Complex Syntax Production is Important to Understanding Children's Grammatical Development
C. Melanie Schuele, PhD
Department of Speech and Hearing Sciences
Vanderbilt University
In the study of child language and child language disorders, far more effort has focused on quantifying and explaining simple sentence production and morphological development than complex syntax production. This imbalance has greatly influenced clinical practice and our understanding of child language impairments. For example, grammatical intervention targets in preschool focus almost exclusively on grammatical morphology and basic sentence structures. Despite the fact that grammatical deficits are considered the core deficit of specific language impairment, complex syntax production in children with specific language impairment has been reported in only a handful of studies. Importantly, for most children complex syntax emerges between the ages of two and three, and by entry to kindergarten, children are typically quite proficient in the production of complex syntax. Typical language learners simultaneously learn grammatical morphology, simple sentence syntax, and complex syntax. This presentation will (a) summarize what is known about complex syntax development in typical learners, (b) present a taxonomy for studying complex syntax, (c) describe language sample and elicited methods for exploring complex syntax production, and (d) summarize our studies of complex syntax production in children with specific language impairment. Lastly, we will consider how the study of complex syntax might lead to a better understanding of the learning challenges of children with primary and secondary language impairments.
Contribution of Hearing Aids to Auditory Perception in Adult Cochlear Implant Recipients
Nathan Peterson
Department of Otolaryngology-Head and Neck Surgery
Indiana University School of Medicine
Modern cochlear implant (CI) encoding strategies and electrode arrays effectively convey temporal information to the CI listener. However, spectral information is poorly conveyed to the auditory nerve. This lack of spectral information has been implicated as a possible cause for some of the limitations of electrical hearing, and studies with CI recipients and normal-hearing adults using CI simulations (i.e. vocoders) have shown that increased spectral information can improve speech perception in noise. For CI recipients with aidable residual hearing in the unimplanted ear, using a conventional hearing aid in addition to their CI is one way to provide additional spectral information. In one study, we administered tests of speech perception in quiet and noise, vowel identification, dialect discrimination and talker discrimination to postlingually deaf adults who used either a cochlear implant or a cochlear implant plus a conventional hearing aid in the contralateral ear. In a follow-up study, the same research participants were given a battery of tests related to music perception and melody recognition. This talk will discuss the results of these studies, as well as the clinical implications for the use of hearing aids in postlingually deaf adult cochlear implant users.
Social Linguistic Aspects of Conversations Between Deaf Peers who use Spoken Language
Jessica Beer, PhD
Department of Otolaryngology-Head and Neck Surgery
Indiana University School of Medicine
Sociocultural theory and developmental research suggest that from birth the social and linguistic environments of normal-hearing children and a child’s active participation in social exchanges are integral to language and vocabulary acquisition, socio-cognitive development, autobiographical memory, and communicative competence. Many deaf children of hearing parents experience degraded or limited opportunities to actively listen and participate in communicative exchanges from birth; therefore their functional use of language and the structure of language that emerges will likely differ from that of normal-hearing children. These differences may in turn affect higher cognitive processes that are mediated by language such as social understanding, executive function, and problem solving. The present study investigates both qualitative (semantic connectivity) and quantitative (duration of talk and silence) social linguistic aspects of conversations of deaf preschoolers who use spoken language during undirected play with a peer. Descriptive data will be presented for several conversational measures including the following: 1) the frequency of exchanges between peers, 2) the proportion of connected verbal and nonverbal turns, initiations, and failed turns, and 3) children’s use of mental state language within different types of turns. This research is highly relevant to understanding more distal outcomes related to hearing loss, such as the ability to use language to initiate and maintain social interaction, and to share and coordinate perspectives and intentions regarding some meaningful activity.
Interventions for Survivors of Pediatric Cancer with Neurocognitive Late Effects: Are We Making Any Progress?
Kristina Hardy, PhD
Assistant Professor
Duke University Medical Center
Department of Psychiatry
A substantial proportion of pediatric cancer patients who have been treated with central nervous system (CNS)-impacting therapies develop neurocognitive deficits over time. These deficits, particularly in the area of attention and working memory (WM) skills, impair academic and social development in childhood, and are later associated with limited vocational opportunities and reduced likelihood of independent living. As such, investigators have increasingly focused on evaluating interventions to mitigate deficits and/or restore cognitive functioning in this population. Drawing on literature describing interventions for children with traumatic brain-injury, learning disabilities, and attention-deficit/hyperactivity disorder (ADHD), several therapeutic programs have been developed and tested in this population. Specifically, pharmacotherapy, educational accommodations and supports, and cognitive remediation have all been evaluated with samples of pediatric cancer survivors. Although each of these interventions has been associated with benefits to survivors’ functioning, effect sizes have generally been small and there remains room for a great deal of improvement. Home-based computerized cognitive training (CT) is a novel approach that has shown robust efficacy in improving working memory in children with attention disorders and localized brain injury. Our research team is currently evaluating the feasibility and efficacy of such interventions delivered to survivors of pediatric cancer with neurocognitive late effects; findings from these projects will be presented. The potential for these interventions to preserve cognitive functioning in children receiving CNS-impacting treatments will also be discussed.
March 18, 2009
New approaches to the assessment and treatment of ADHD and Attention Difficulties
David Rabiner, PhD
Department of Psychology & Neuroscience
Duke University
This talk will cover recent studies that incorporate new methods to aide in the assessment and treatment of ADHD. In the assessment realm, limitations in the utility of rating scales and the contribution of quantitative EEG (QEEG) will be highlighted. Treatment research will review recent data on neurofeedback, working memory training, and computerized attention training.
Studies on the role of attention in speech perception: From perceptual learning to training attention
Alexander Francis, PhD
Department of Speech, Language, and Hearing Sciences
Purdue University
In this talk I’ll review the results of a series of studies in which adult perceptual learning of speech sounds is elucidated in terms of the operation of general mechanisms of selective attention. I will then present some preliminary results from a new research program that (in a certain sense) turns this problem around. In these studies, I investigate the role that basic cognitive mechanisms such as selective attention and working memory might play in online perception of speech, focusing in particular on the manner in which improvement (i.e. due to training) or decline (i.e. due to normal aging or neurologic disease) in the operation of these mechanisms affects speech perception under adverse listening conditions.
Lexical Tone Production and Singing Proficiency of Prelingually Deafened Children with Cochlear Implants
Li Xu, MD, PhD
School of Hearing, Speech and Language Sciences
Ohio University
The coarse pitch information in cochlear implants might hinder the development of lexical tone production and singing in the prelingually-deafened pediatric users. In the present talk I will provide a brief background on pitch coding in the cochlear implant systems. I will then describe several recent studies in which quantitative measures of tone production and signing by the children with cochlear implants have been developed. Compared to the normal-hearing children, prelingual deaf children with cochlear implants showed remarkable deficits and tremendous individual differences in the accuracy of tone production and proficiency of singing. Future studies are warranted to elucidate the contributing factors for the performance variability in children with cochlear implants.
2008
Speech and Non-Speech Timing Processes
Howard N. Zelaznik, PhD
Department of Health and Kinesiology
Purdue University
Most human performance situations require individuals to be temporally precise in order to successfully achieve task-goals. In communicative skills, such as speech, timing and temporal coordination, appear to provide an a priori constraint. In the present talk, I will summarize some of our own work which examines whether people possess a general purpose movement timing process. Then, I will present some already published, and some just completed work examining timing processes in individuals who stutter, and in children who are diagnosed with specific language impairment. I will infer that the examination of similar task performance across different language/speech disorders can serve as a diagnostic tool to classify disorders as primarily speech-motor versus linguistic.
Better Recognition of Supra-segmental Speech Information with Cochlear Implants
Xin Luo, PhD
Department of Speech, Language, and Hearing Sciences
Purdue University
Cochlear implants (CIs) partially restore hearing sensation to profoundly deaf people via direct electric stimulation of the surviving auditory neurons. While CI users’ recognition of segmental speech information has been extensively studied, far less attention has been paid to CI users’ recognition of supra-segmental speech information (i.e., lexical tones, intonation, duration, and stress, etc.). With the latest speech processing strategies, CI users are only capable of moderate levels of Chinese tone and vocal emotion recognition, due to the limited pitch cues available with the implant device. Better representation of supra-segmental speech information is necessary to further improve CI users’ speech communication capabilities. In this talk, acoustic CI simulations and psychophysical studies will be described, which reveal the importance of spectral, temporal, and pitch cues to Chinese tone and vocal emotion recognition with CI. To enhance Chinese tone and speech recognition for CI users, strategies that modify speech amplitude envelope or combine electric and acoustic hearing will be presented. To conclude the talk, other strategies that may better transmit pitch cues to CI users, as well as other factors that may affect Chinese tone recognition with CI will be discussed.
Speech accuracy in early-implanted children: Are we getting it right?
Andrea D. Warner-Czyz, PhD
Department of Communication Disorders
The University of Texas at Dallas
Although earlier cochlear implantation is associated with improved speech outcomes, it is still difficult to predict which children will develop adequate speech production and perception skills and which children will exhibit poorer communication outcomes. Age alone has failed to serve as a reliable predictor of the broad range of speech accuracy scores in this population. The inability to predict variability in early speech accuracy limits the ability to intervene and improve speech accuracy in severe-to-profound hearing loss who receive cochlear implants (CI). Although it is said that children who receive a CI device by 2 years of age acquire speech and language milestones on par with normal hearing peers, considerable variability in speech accuracy performance exists even for these early-implanted children. Potential factors that could improve prediction include early auditory speech perception skills, initial fast mapping capacities, and early speech production patterns. These three elements underlie the acquisition of speech accuracy, or the matching of sounds like consonants and vowels in the target word. In this talk, I will explore the influence of auditory speech perception, fast mapping, and speech production patterns during the early word period on speech accuracy in children who receive CI before 2 years of age. Initial indicators of communication abilities need to be defined to identify children at risk for lower performance on speech accuracy and intelligibility measures. This more comprehensive model of predicting early speech accuracy could change the way that we monitor speech, language, and hearing development in and treat early-implanted children.
Training to Ignore vs. Training to Attend: The Distribution of Selective Attention in the Acquisition of a Foreign Phonetic Contrast
Maria Kondaurova, PhD
Program in Linguistics
Purdue University
This study compares the ability of three auditory training methods to redirect native Spanish listeners' attention from the use of duration to spectral properties when identifying American English tense and lax vowels. Both adaptive training and cue inhibition training increased attention to spectral cues and decreased attention to duration, and both were more successful at changing perceptual weighting than was training with a natural cue distribution. However, differences between adaptive and inhibition training suggest that phonetic learning may involve two distinct cognitive processes, cue enhancement and cue inhibition, that function to shift selective attention between separable acoustic dimensions.
Realizations of consonant clusters by children with cochlear implants
Steven B. Chin, PhD
Department of Otolaryngology-Head and Neck Surgery
Indiana University School of Medicine
Consonant clusters are of interest in both developed and developing languages, because they embody multiple characteristics of phonological systems, including both segmental and phonotactic constraints. In this talk, I will discuss some of the theoretical approaches to the analysis of consonant clusters in developing phonologies, as well as some specific data regarding consonant cluster realizations from children with cochlear implants. For 10 children with cochlear implants, the majority of target consonant clusters at both an earlier and a later interval were correctly produced. Incorrect realizations with two segments reflected markedness constraints holding generally for singletons, including two highly-ranked constraints *LIQUID and *VELAR. Incorrect single-segment realizations generally followed the sonority dispersion principle, but two conflicts with sonority that reflected more highly ranked *VELAR and *FRICATIVE have also been attested in children with normal hearing. Also consistent with children with normal hearing, epenthetic and null realizations were relatively rare. In general, children with cochlear implants realized consonant clusters in a similar way to children with normal hearing, and a common set of basis phonological principles and mechanisms can be applied to data from both groups.
Working Memory Training and Implicit Learning
Althea Bauernschmidt
Department of Psychological and Brain Sciences
Speech Research Lab
Indiana University
Recent studies have shown that working memory can be improved through training and this improvement generalizes to other cognitive measures. Working memory studies typically focus on the retention of random sequences; however, a lot of what working memory is used for is not random. The goals of this study were to determine what effect probabilistic structure has on adaptive training of working memory and how differing levels of structure affect generalization to other cognitive tasks. Participants received four days of working memory training that was either adaptive or non adaptive with sequences that were constrained or probabilistic. A battery of cognitive measures was taken at pre- and post- test. Probabilistic structure provided beneficial effects on adaptive training of working memory in as little as four hours of training. Moreover, these benefits carried over to improvements on measures of non-verbal reasoning and executive function.
Infant-Directed Speech, Maternal Depression, and Infant Associative Learning
Peter Kaplan, PhD
Department of Psychology
University of Colorado-Denver
Infant-directed speech (IDS) is marked by exaggerations is speech prosody that increase its ability to modulate infant state and attention relative to adult-directed speech (ADS). Research in our laboratory has investigated effects of IDS on infant association learning. Because IDS leads to a transient increase in an infant’s state of arousal, we hypothesize that another stimulus paired with IDS will acquire the ability to better control infant visual attention. Consistent with this, using a conditioned-attention paradigm, we found that a brief segment of affectively positive IDS (in comparison with ADS) non-specifically facilitates 4-month-olds’ voice-face associative learning. The extent to which 4-month-olds’ learning is facilitated correlates with the mean extent of fundamental frequency (F0) modulation in the IDS. Infant-directed speech produced by depressed mothers, which contains significantly lower F0 modulation than that produced by non-depressed mothers, is relatively less effective at promoting infant learning. However, although 4-month-old infants of depressed mothers acquire associations in response to high-quality IDS produced by an unfamiliar non-depressed mother, 5- to 13-month-old infants of depressed mothers on average do not. In contrast, infants of chronically depressed mothers are especially responsive to male IDS. We present several lines of evidence to suggest that infants learn to “tune-out” female IDS when the infant’s primary caregiver is low in emotional availability. Infants’ responding to IDS appears to be influenced both by its initial perceptual salience and by social-experiential factors that affect its “meaning” for the developing infant.
Computing Phonotactics On The Fly
Peter T. Richtsmeier
Department of Linguistics
University of Arizona
In this talk, I will present a series of experiments which address the generalizability of perceptual learning. More specifically, I examine how well children are able to generalize a phonotactic pattern to their own speech based on a short perceptual familiarization with that pattern. Previous studies (e.g., Bradlow, Pisoni, Akahane-Yamada, & Tohkura, 1997; Bradlow, Akahane-Yamada, Pisoni, & Tohkura, 1999; Flege, 1995, 1999; Wang, Jongman, & Sereno, 2003) have shown that adult L2 learners are better able to produce nonnative contrasts following rigorous perceptual learning. Similarly, Richtsmeier, Gerken, Goffman & Hogan (in preparation) showed that L1 learners are better able to produce a novel word when they first familiarized with 10 productions of the word by 10 different talkers. For my dissertation, I conducted a series of experiments to explore the possibility that perceptual learning is responsible for the phonotactic frequency effects seen in child speech (see Storkel & Morrisette 2002 for a review).
In all of the experiments, four-year-olds listened to nonsense CVCCVC words during a training phase and were later asked to produce different CVCCVC words with the same medial consonant sequence (e.g., in Experiment 1 children were familiarized with /fp/ in mæfpem and asked to say neIfpen at test time). Token frequency (the number of talkers producing each word) and type frequency (the number of words containing the medial consonant sequence) were the important factors.
The critical result is that familiarization with multiple words sharing a consonant sequence, or type frequency, influences generalization, but token frequency does not. The results support the claim that L1 learners make phonological generalizations as they hear speech. Furthermore, the results are relevant to a number of theories of phonological acquisition (e.g., Albright & Hayes 2003, Bailey & Hahn, 2001, Pierrehumbert 2003a, 2003b).
If time and recruitment efforts allow, I will also discuss an experiment that is currently being run which removes talker variability from the familiarization phase. Some theories of phonotactic learning (e.g., Pierrehumbert 2003a, 2003b) suggest that talker variability is necessary for generalization.
A disconnect between phonetics and phonology: New evidence from affricates
Anne Pycha
University of California, Berkeley
Many phonetic and phonological processes resemble one another, which has led some researchers to suggest that phonetics and phonology are essentially the same. This study compares phonetic and phonological processes of lengthening in Hungarian affricates by combining evidence from speech production experiments and theoretical argumentation. Duration measurements collected from Hungarian speakers (n=14) show that phonetic lengthening in affricates observes a strict respect for locality (the lengthened portion is always that which lies closest to the trigger), but phonological lengthening does not (the lengthened portion is that which lies farthest from the trigger), lending support to the idea that these two processes are very different indeed. Drawing on distributional evidence from Hungarian phonology, as well as generalizations about the creation of geminates cross-linguistically, I argue that the source of this difference is not in the representation of affricates, but in the very nature of the lengthening operations themselves.
Acquisition of Tense Marking in Children with Cochlear Implants
Ling-yu Guo, MA
Department of Communication Sciences and Disorders
University of Iowa
We examined the acquisition of tense marking in prelingually-deaf children with cochlear implants (CIs) implanted before age 2. Six children with CIs retold stories after three, four and five years of listening experience. Typically-developing children matched for hearing experience were controls. Results revealed that older children marked tense more accurately than younger children. Children with CIs were significantly less accurate than the typically developing children regardless of age. Errors tended to be omission rather than commission errors in both children groups. We conclude that children implanted before age 2 may learn tense marking albeit with a delayed pattern.
Factors influencing the acquisition of s-clusters
Ashley W. Farris-Trimble
Indiana University
In this talk, I present the results of several studies exploring children's acquisition of s-clusters and the relationship between acquisition and fully-developed languages. S-clusters (the consonant sequences that begin words like 'snake', 'slow' and 'spot') are interesting to acquisition researchers because they have an unusual phonological structure and because they tend to be late-acquired both for normal-developing and for phonologically delayed children. Given the continuity hypothesis (Pinker 1984), we expect developing languages to reflect possible fully-developed languages. The first study asked in what order do children acquire s-clusters? Through an examination of the phonologies of 110 children with phonological delay, the following pseudo-order of acquisition was determined: sp, sn > st, sw > sm > sk > sl. This pseudo-order does not seem to reflect an expected order of acquisition based on the Sonority Sequencing Principle and sonority distance, which would predict that clusters with the greatest sonority difference should be acquired first. An implicational relationship also obtained: no child produced the cluster [sl] without also producing each of the other s-cluster types. Because the order of acquisition data presented unexpected results with respect to sonority, further studies were conducted to examine possible language-specific or cross-linguistic explanations. A second study explored potential language-specific predictors by examining the lexical characteristics (frequency and neighborhood density) of English words beginning with s-clusters. Neither of these lexical characteristics predicted the order of acquisition, with the biggest mismatches occurring in the s+nasal and s+liquid clusters. This null result raised the question of whether cross-linguistic universals could better explain the acquisition facts. The third study thus asked whether children's s-cluster inventories are similar to the s-cluster inventories of fully-developed languages. 231 languages were analyzed in order to determine any typological universals. It was found that the presence of an s+nasal cluster implies the presence of an s+obstruent cluster, suggesting that s+nasal clusters may pattern structurally as adjuncts. Other expected predictions regarding sonority-based implicational relationships among the s-clusters were not borne out, and there was no implicational relationship between s+liquid and the other s-clusters, as there was for the acquisition data. This reveals a seeming discontinuity between developing and fully-developed languages. However, the different structural analysis of s+nasal clusters may explain their relative unmarkedness in acquisition, and the lack of other implicational relationships in fully-developed languages indicates that sonority may not be the best predictor of inventories. If this is the case, then there is no discontinuity between developing and fully-developed languages after all.
Some New Findings on Executive Function, Sequence Memory and Cognitive Control in Deaf Children with Cochlear Implants
David B. Pisoni, Christopher M. Conway, William Kronenberger, David L. Horn, Shirley Henning and Esperanza Anaya
Clinical research on deaf children with cochlear implants has been intellectually isolated from the mainstream of current research and theory in cognitive neuroscience, cognitive psychology and developmental neuropsychology. As a consequence, the major clinical research problems have been narrowly focused on studies of speech and language outcomes and efficacy of cochlear implantation as a medical treatment for profound hearing loss. As noted in both of the NIH consensus statements on cochlear implants in 1988 and 1995, little if any research has investigated the underlying psychological and neurocognitive factors that are responsible for the enormous individual differences and variability in the effectiveness of cochlear implants. In this talk, we report some new research findings on executive function, sequence memory and cognitive control in prelingually deaf children who have received cochlear implants. Our results reveal that several domain-general neurocognitive processes related to executive function and cognitive control processes such as working memory capacity, fluency-speed, inhibition and organization-integration sequencing skills are correlated with traditional clinical speech and language outcome measures. These neurocognitive processes reflect the global coordination, integration and functional connectivity of multiple underlying brain systems used in speech perception, production and spoken language processing. We suggest that executive function and organization-integration processes contribute an additional unique source of variance to speech and language outcomes above and beyond the conventional demographic, medical and educational factors. Understanding the neurocognitive processes responsible for variability in spoken language processing will help both clinicians and researchers explain and predict individual differences in speech and language outcomes following cochlear implantation. These new findings have implications for improving the diagnosis, treatment and early identification of young deaf children who may be at high risk for poor outcomes following cochlear implantation.
Language development and reorganization: Lessons learned from functional neuroimaging in partial epilepsy
Brenna C. McDonald, PsyD, MBA
IU Center for Neuroimaging
Division of Imaging Sciences
Department of Radiology
Localization of receptive and expressive language regions in the brain has long been an area of active research interest for cognitive neuroscientists and clinical researchers alike. Early neurosurgical investigation using intracortical electrical stimulation demonstrated discrete frontal and temporal regions critical for expressive and receptive language, initially thought to be unilaterally represented. Accurate lateralization and localization of these regions is critical for neurosurgical populations (e.g., brain tumor, focal epilepsy), and exploring the potential for reorganization of language functioning has important implications for predicting postsurgical outcomes and understanding the trajectory of language development in typically developing children as well as those with neurodevelopmental disorders. Functional neuroimaging techniques, including functional MRI (fMRI), offer the opportunity to examine language functioning in vivo in a noninvasive manner, using probes that can be adapted for developmental and cognitive level. Temporal lobe epilepsy (TLE), a common focal epilepsy with typical onset in early childhood, offers a unique clinical population in which to study these questions. A growing body of fMRI research has demonstrated alterations in language functioning and brain organization in children with TLE, and the ability of the brain to reorganize around damaged tissue to spare language over time. fMRI language probes have also been demonstrated to predict postsurgical outcome, suggesting that we may be able to use fMRI to replace current invasive methods for preoperative language lateralization. This presentation will discuss research findings to date, as well as ongoing work in the Center for Neuroimaging using fMRI to examine language and memory processing in children with TLE.
2007
Interactions between language and motor development in children with SLI
Lisa Goffman, PhD
Department of Speech, Language, & Hearing Sciences
Purdue University
The central aim of my research is to integrate theories of language production and motor action into new accounts of specific language impairment (SLI). SLI is a disorder that affects approximately 7% of children at the time they enter kindergarten. Many current approaches to SLI focus entirely on language factors. However, language is expressed through movement, and deficits in motor skill have been implicated in children with SLI. Current neurophysiological hypotheses about relations between language and action further support a rethinking of how these domains interact in normal and disordered development. The studies presented will assess how motor implementation, at the level of articulation, is modified as a function of sentential, lexical, and prosodic variables. Further, I will address how motor and language deficits interact in children with SLI.
Theory of Mind and Language in Children with Cochlear Implants
Kimberly Peters and Ethan Remmel
Western Washington University
Thirty children with cochlear implants, mean age 7.5 years, and 30 children with normal hearing, mean age 5.3 years, were tested on theory of mind and language measures. Children with cochlear implants showed little to no language delay, whereas theory of mind performance was slightly delayed relative to hearing norms, but good relative to deaf children of hearing parents in previous research. Performance on false belief tasks was best predicted by age, general language ability and spontaneous use of mental state vocabulary, specifically cognitive vocabulary. Use of complementation did not explain any additional variance in false belief understanding. Children with cochlear implants showed a slightly atypical sequence of acquisition of theory of mind concepts, perhaps due to atypical social experience. Results suggest that cochlear implantation can benefit spoken language ability, which then benefits theory of mind, perhaps by increasing access to mental state language.
The Development of Attention: Basic and Applied Perspectives
John Colombo, PhD
Department of Psychology University of Kansas
Attention has long been considered to be a fundamental component of the information processing system. While the term "attention" is commonly considered to reflect a unitary construct, research suggests that the construct is mediated by the operation of a set of dissociable functions. This presentation will describe work from our laboratory which has been devoted to delineating these functions, establishing their developmental courses, and then using the developmental courses of these functions as both predictors and outcomes of other developmental indices. Applications to clinical populations will be discussed.
The Dynamics of Attention Engagement: Within Subject Inconsistency in Infants' Word Recognition
Robin Panneton
Department of Psychology
Virginia Polytechnic Institute and State University
An important issue in the study of infants' processing of language is how best to gauge attention, encoding, and recognition of sound in listeners with limited behavioral competency. Although a variety of methods exist for this purpose, the predominant favorite in the field of infant research is to measure the duration of infants' fixations to a visual event, when hearing a concurrent sound is contingent on looking. Because there is reason to believe that infants' processing of unimodal v. multimodal events is not equivalent (Aslin, 2007), it is important to use knowledge about infants' attention to visual events before employing them in experiments designed to examine auditory processing. The purpose of this talk is twofold: (1) to present data on developmental changes in infants' attention (defined both behaviorally and psychophysiologically) to both static and dynamic visual events, and (2) to examine how visual events both enlighten and obscure evidence for word recognition in individual infants based on the likelihood that the visual events will or will not engage infants' attention in a unimodal context.
How listeners make sense of phonetic variability in speech
Laura Dilley, PhD
Departments of Psychology and Communication Disorders
Bowling Green State University
Speech is a complex amalgam of several time-varying, acoustic properties. The question of how listeners decode this signal is informed by studies of the scope of phonetic variability in speech. This talk focuses primarily on understanding the nature of prosodic (i.e., pitch, timing and rhythm) variability in speech, and how such information is perceived by listeners. Several studies are reported which focus on the perception of prosodic cues in controlled speech stimuli, as well as in large speech corpora. Recent results suggest that pitch and timing cues can influence not only how listeners isolate words from the continuous speech signal, but also how they access words from the lexicon. In addition, the principles used by listeners to organize pitch and timing information in speech appear to apply to other kinds of auditory stimuli, including music. These findings have the potential to inform our understanding of both adult spoken language processing, as well as infant language acquisition.
Preschoolers’ Play Negotiations: Implications for Social Cognition
Jessica Beer, PhD
PhD graduate in Developmental Psychology, Graduate Center at the City University of New York
The analysis of negotiations appreciates language not only as a communicative tool but also as a representational tool necessary for sharing and gaining knowledge. It has been argued that the acquisition and mastery of spoken language changes cognition during the preschool years (Nelson, 1996). Relevant to preschool-age pretend play negotiations, the use of language as a representational system allows children to begin to refer to objects not physically present and to share concepts, to plan what to play, to enact narratives during pretend play, and to share feeling, intentions, and perspectives with a play partner. The findings of this study indicate that between the ages of three and five there is a shift from the use of less to more socially engaging discourse, less to more internal state referencing and justifications of perspective, and towards more sophisticated and complex types of negotiations that require the active consideration and transformative efforts of the play partners. The results of this study have implications for theory of mind research, pretend play contexts, collaborative cognition, and more broadly for our understanding of the complex relationship between language and cognition during early and middle childhood.
Electrically Evoked Cortical Potentials
Carolyn J. Brown, PhD
Professor, Department of Speech Pathology and Audiology, University of Iowa
We have spent much of the last two decades exploring methods of recording and clinical applications for electrically evoked, but peripherally generated auditory potentials from cochlear implant users. While these studies have greatly expanded our understanding of how electrical signals are processed at the level of the auditory nerve, our hope was that we would also be able to use these relatively simple measures of peripheral neural response to electrical stimulation to either predict performance with the cochlear implant or to facilitate the fitting of the speech processor for pediatric implant users. Our success to date, in accomplishing that goal, has been somewhat limited. Recently, we have begun a series of studies in which the focus is on more centrally generated, electrically evoked auditory potentials. While recording these responses can be challenging, particularly for pediatric implant recipients, we have reasoned that there is at least the potential for stronger correlation between these responses and perception. In this talk, I will describe the paradigm we are using to elicit these responses, discuss our preliminary results and outline our plans for future studies.
Are there constraints on the long-term development of speech in children with cochlear implants?
J. Bruce Tomblin, PhD
DC Spriestersbach Distinguished Professor in Liberal Arts & Sciences, University of Iowa; Director, Child Language Research Center
There has been a long standing interest in whether critical or sensitive periods affect the speech and language development of children receiving cochlear implants. Most if not all of this interest has focused on whether experience provided by an implant at ever earlier points in development result in better outcomes. Interestingly, most of the literature on critical periods in speech and language has been concerned with the presence and nature of a closing of the period during later childhood. In this talk we will look at the long-term pattern of speech sound development in children and adolescents with cochlear implants. These data will provide some useful clinical insights into the ultimate levels of achievement of these individuals and the length of time required for this growth. Also, we will look to see if there is evidence of a maturationally governed closing of a critical period for speech.
Information Processing in Preterms and Full-Terms: Infant Abilities and Their Consequences
Susan A. Rose, PhD
Professor of pediatrics
Albert Einstein College of Medicine
This presentation will focus on the results of two longitudinal studies from our lab, both of which deal with the infant roots of later cognition. Findings on preterm/fullterm differences in information processing during infancy and early childhood will be discussed, concentrating on four areas -- attention, processing speed, memory and representational competence. I'll also discuss the relation of the infant measures to later cognition, and model these relations with a developmental cascade. Finally, I'll present some preliminary findings showing the relation of different aspects of memory and representational competence from 1 year to language outcomes at 1, 2, and 3 years, focusing on those infant measures that have a unique relation to later language
Implications of recent research on sign languages for our understanding of 'language' and applications to Deaf Education
Ronnie B. Wilbur, PhD
Professor of speech, language, and hearing sciences
Purdue University
Research on sign languages around the world has demonstrated that natural signed languages share linguistic characteristics with spoken languages with the exception of the modality of perception (visual v. auditory) and production (manual/facial v. oral).
This talk will outline some of the design features of 'language' and how those are expressed in American Sign Language (ASL) and others that we study. Implications of these findings contribute to our research on automatic recognition of signs and facial expressions.
Critically, the similarities between spoken and signed languages gives rise to enhanced educational development by creating typical bilingual situations in which one language primes acquisition of the other. We take advantage of this by developing novel approaches to Deaf Education using 3-D animation technology to teach math and science to signing K-6 deaf students.
Development of infant attention to multimodal stimuli: Relation between arousal and specific attention processes.
John Richards, PhD
Department of Psychology
University of South Carolina
Infants show development in their attention to multimodal stimuli, with increasing preferences for such stimuli in the first six months of life. This preference is demonstrated primarily when infants engage in "sustained attention" (arousal; alertness), and affects specific attention processes such as blink reflex suppression, distractibility, and visual gaze. Developmental changes are thought to occur both in the arousing aspect of multimodal stimuli and in the specific attention processes.
2006
Psychological aspects of cochlear implantation: predicting outcome and benefit in adults and children
John Knutson, PhD
Department of Psychology
University of Iowa
After a quarter century of clinical research on the outcome of cochlear implantation with various populations of postlingually- and prelingually-deafened populations, the saliency of variability in implant outcome persists. Thus, an interest in establishing reliable and valid predictors of implant outcome continues to be a focus of research. At the inception of the clinical application of cochlear implantation, it was hypothesized that psychological variables might be useful in predicting implant benefit. The seminar will review findings from 20 years of research examining the role of personality attributes and specific cognitive abilities in predicting implant outcome. By considering data from first-generation multichannel implants as well as contemporary implant technologies, findings suggest that individual differences in some specialized cognitive abilities continue to account for variance in several different indices of implant benefit.
Rule Learning in Infancy
Scott Johnson, PhD
Associate professor of psychology and neural science
New York University
A hallmark of human cognition is its flexibility: our ability to acquire information, reason, categorize, hypothesize, and predict future events under a wide variety of circumstances. Two central issues involved in investigations of cognitive flexibility and knowledge acquisition are (a) the distinction between learning simple associations vs. more abstract rules, and (b) the effects of the nature of the stimulus input to learning mechanisms, a phenomenon sometimes referred to as domain-specificity. The development of abstract reasoning in humans, likewise, is of considerable theoretical importance, yet there has been no systematic investigation in the literature of its origins in infants. I will describe the recent efforts toward these goals from my lab. The emphasis has been twofold, following the issues highlighted previously. First, we investigated whether young infants are more adept at statistical learning or rule learning. Second, and in parallel, we have explored the possibility that rule learning is facilitated by particular kinds of input, such as speech sounds (when learning an auditory rule) vs. simple colored shapes (when learning the same rule instantiated in visual stimuli). The data suggest that rule learning may represent a more protracted developmental process relative to statistical learning, and that speech facilitates early rule learning. These findings lend support to views of language acquisition that favor domain-specific learning mechanisms.
Effects of deafness and American Sign Language on vision and short-term memory
Daphne Bavelier, PhD
Department of Brain and Cognitive Sciences
University of Rochester
Evidence for re-organization of visual and short-term memory functions in deaf individuals who are native users of American Sign Language will be reviewed. For vision, it will be argued that deafness does not lead to better or worse visual skills, but rather that it selectively changes the spatial distribution of visual attention. The known neural correlates of this behavioral change will be discussed, and the role of multi-modal areas in the reorganization observed will be highlighted. For short-term memory, it will be shown that the reliance on American Sign Language changes short-term memory capacity, most likely due to a lesser reliance on temporal order in the sign modality. Consequences for the cognitive evaluation of deaf populations will be discussed.
Factors affecting hearing-impaired listeners' difficulty in noise
Peggy Nelson, PhD
Department of Speech-Language-Hearing Sciences
University of Minnesota
Listeners who use hearing aids and cochlear implants are surprisingly adversely affected by background noise under certain circumstances. In our work, even when the level of the noise was approximately 10 to 15 dB lower than that of the speech, background noise significantly reduced speech recognition scores of implant users. Hearing aid users with appropriate amplification achieve only half of the expected benefit of momentary breaks in background noise. Several reasons have been proposed for this reduction, including: the reliance of impaired listeners on speech envelopes which are perturbed by random noise, poor spectral representation which causes severe reduction in the redundancy of speech, and poor speech/noise segregation due to weak fundamental frequency representation. Work from our laboratory suggests that each of these may play a role in the adverse effects of noise. Evidence for each of these factors will be presented for listeners' understanding of phonemes, words, and sentences in steady and in gated noise. Implications for fitting and evaluating sensory aids will be addressed.
An examination of the effect of talker familiarity on the sentence recognition skills of cochlear-implant users
Brittan Barker, PhD
Department of Otolaryngology-Head and Neck Surgery
University of Iowa
Objectives: to determine the role of talker-specific information in speech perception via a cochlear implant (CI) and the extent to which this information affects accurate analysis of the speech signal's linguistic information. Study Design: A mixed 2 X 2 design was used. The between-subjects variable was participant type (adult cochlear-implant users, adult normal-hearing listeners) and the within-subject variable was talker type (familiar, novel). Methods: The effect of talker-familiarity on sentence recognition was studied with experiments modeled after those of Nygaard and Pisoni (1998). Participants were first trained to recognized different talkers' voices. After being tested on how well they learned the voices, the participants completed a sentence recognition test in noise to assess the role of talker-familiarity on their sentence recognition skills. Results: Differences were noted between normal-hearing and CI listeners. The CI listeners recognized the voices with 59.31% accuracy and the normal-hearing listeners achieved 92.64% accuracy. The CI listeners also performed overall more poorly than the normal-hearing listeners on the sentence recognition test, but neither group's sentence recognition accuracy benefited from talker familiarity. Conclusions: Although the present research failed to provide insight into talker familiarity's effect on the sentence recognition skills of CI and normal-hearing listeners, it did demonstrate that CI users can be trained to recognize voices with notable accuracy (as were the normal-hearing listeners). The present studies also showed that CI listeners appear to perceive and use talker-specific information differently than normal-hearing listeners.
Projecting the end of a speaker's turn: A cognitive cornerstone of conversation
J.P. de Ruiter, PhD
Language and Cognition Group
Max Planck Institute for Psycholinguistics [Nijmegen, The Netherlands]
Listeners in a conversation need not only process the content of speakers' utterances and prepare responses, but they also need to anticipate the moment in time that speakers finish their turn, allowing them (the listener) to start their own contribution right on time. I will present quantitative evidence from natural data showing that listeners are indeed very accurate in anticipating (or 'projecting') the end of a speaker's turn.
But how are listeners able to be so accurate in projecting the end of a speaker's turn? What information do they use? A few authors have suggested that syntactic information provides the main cue, while others have argued that the intonational contour (melody) is the listener's main source of information for accurate 'projection'.
In this talk, I will describe an on-line experiment in which we tested these hypotheses by manipulating the presence of lexico-syntactic content and the intonational contour of utterances recorded from natural conversations. When hearing the original recordings, subjects could indeed anticipate turn endings with the same high degree of accuracy found in real conversations. When we entirely removed the intonational contour from the utterances (leaving words and syntax intact), there was no change in subjects' accuracy of end-of-turn projection - they were just as accurate as with the original recordings. But when we made the words unrecognizable, while leaving intonational contour intact, subjects' performance deteriorated significantly. These results establish that the lexico/syntactic content of an utterance is necessary (and possibly even sufficient) for projecting the moment of its completion, and thus for regulating conversational turn-taking. By contrast, and perhaps surprisingly, intonational contour is neither necessary nor sufficient for end-of-turn projection. Finally, I will discuss some theoretical and practical implications of these findings.
Morphological awareness in children's literacy and language development
Catherine McBride-Chang, PhD
Department of Psychology
Chinese University of Hong Kong
Despite the clear importance of phonological processing for reading and vocabulary acquisition across languages, there are a variety of reasons to expect that morphological awareness may be additionally useful for understanding literacy and language development. In this talk, I will highlight two aspects of morphological awareness, morphological construction and homophone awareness, and discuss their associations to word reading and vocabulary knowledge among children speaking Cantonese, Mandarin, Korean, or English as a native language. With data from nine different studies on children from kindergarten through sixth grade, I will demonstrate why a focus on morphological awareness, in addition to phonological processing, may be both theoretically and practically useful in understanding language and literacy development and impairment across languages.
Verb learning and the early development of sentence comprehension
Cynthia Fisher, PhD
Department of Psychology
University of Illinois at Urbana-Champaign
Children as young as two years old use sentence structure to learn the meanings of verbs; this is known as syntactic bootstrapping. This talk will explore how syntactic bootstrapping begins, and how it interacts with early progress in syntax acquisition. I will present evidence for two key claims: First, children treat the number of nouns in the sentence as a cue to the sentence's semantic predicate-argument structure. The number of nouns in the sentence is useful because it provides a probabilistic indicator of the verb's number of arguments. Second, early syntactic bootstrapping requires that children represent language experience in an abstract mental vocabulary that permits rapid generalization of syntactic learning to new verbs. I will present evidence that language-specific grammatical learning, such as detecting the significance of word order in English, transfers quickly to sentences containing new verbs, permitting progressively finer constraint on sentence interpretation and verb learning.
Baby statisticians? Learning about speech and music
Jenny Saffran, PhD
Department of Psychology
The Waisman Center
University of Wisconsin-Madison
How do infants discover structure in their environments? Two of the most complex domains confronting infant learners are language and music. In this talk, I will consider possible roles for statistical learning-the ability to track patterns in the input-for infants acquiring speech and musical knowledge. Implications for theories of infant language acquisition will be considered, as well as possible implications for atypically-developing infants.
Listening to multiple channels with a cochlear implant: Interactions in envelope, place, and loudness domains
Monita Chatterjee, PhD
Department of Hearing and Speech Sciences
University of Maryland
The auditory system needs to be able to break down an incoming sound into its component parts (analysis) before it reconstructs the auditory scene by grouping those elements that belong together and separating those that do not (synthesis). For cochlear implant (CI) listeners, the first stage presents difficulties: sparse spectral sampling, spectral degradation and possibly poor neural survival result in a reduction in the net information capacity of the system. In particular, listening to multi-channel stimuli is limited by large amounts of across-channel interference. My lab is using a psychophysical approach to study multi-channel auditory processing by CI listeners. This talk will describe the results of a variety of experiments conducted with CI listeners aimed at discovering peripheral and central interactions between component channels of a multi-channel complex. Effects of such interactions on envelope, place, and loudness coding will be considered, as well as implications for speech perception by CI listeners in quiet and in competing noise.
The effects of language and linguistic experience on the identification of bilinguals' voices across languages
Stephen J. Winters, PhD
Speech Research Laboratory
Department of Psychological and Brain Sciences
Indiana University Bloomington
It has traditionally been assumed that the indexical properties of speech-i.e., the information in the speech signal which listeners can use to identify personal characteristics of the speaker-are wholly independent of the linguistic properties of speech (Abercrombie, 1967). This strict dichotomy between the linguistic and "extralinguistic" indexical properties of speech has been challenged in recent years, however, by a growing body of evidence indicating that knowledge of a speaker's voice facilitates linguistic processing in tasks such as word recognition (Goldinger, 1996), phoneme identification (Mullennix and Pisoni, 1990) and stem completion (Schacter and Church, 1992). It has also been shown that knowledge of the language that a person is speaking can facilitate the identification of that person's voice (Goggin et al, 1991; Thompson, 1987; Schiller and Koster, 1996).
This study tested the independence of the linguistic and indexical properties of speech by investigating the ability of listeners to identify the voices of bilinguals across two languages, English and German. Native English listeners with no knowledge of German were trained to identify the voices of ten L1-German/L2-English bilinguals over four days. On each training day, listeners identified talkers from isolated, monosyllabic words. Half of the listeners heard only English words while the other half heard only German words. On the final day of the experiment, listeners were tested on their ability to identify the same talkers while they were speaking in the language that had not been used during training.
Results showed that listeners' performance on the identification task consistently improved over the four days of training. Improvement in identification accuracy progressed at the same rate, regardless of which language the listeners heard. Listeners also successfully generalized their knowledge of the talkers' voices to the novel language stimuli on the final day of the experiment. The extent to which they were successful in making such a generalization depended on what language they had been trained on, however. Listeners who were trained on English were worse at identifying the speakers in German than in English. Listeners who were trained on German, however, identified speakers equally well in both languages.
The fact that listeners were able to generalize their knowledge of the talkers' voices across languages indicates that at least some indexical properties must be language-independent. However, since listeners are better able to generalize knowledge of talkers' voices to a language they are familiar with, there must also be some indexical properties of speech which are language-specific. The ability to make use of these language-specific indexical properties of speech in perception thus appears to form part of a listener's linguistic competence.
A follow-up study on the ability of listeners to discriminate between bilinguals' voices in an AX discrimination task provided converging evidence that linguistic experience affects the perception of the indexical properties of speech. Listeners who had been trained to identify the voices of the bilingual talkers were better able to discriminate between those voices than listeners who had not received such training. However, listeners who had been trained with German stimuli were significantly less biased to perceive the talkers of German words as the "same" than listeners who had been trained with English stimuli.
The possible implications of the perceptual interdependence of the linguistic and indexical properties of speech for cochlear implant users will also be discussed in light of some preliminary data on the ability of normal-hearing listeners to discriminate between voices that have been presented to them through a cochlear implant simulator.
2005
Perceptual learning of speech processed through an acoustic simulation of a cochlear implant
Rose Burkholder, PhD
Department of Psychological and Brain Sciences
Indiana University Bloomington
Recent research on auditory perceptual learning has been fueled by interest in cochlear implant (CI) users. Post-lingually deafened CI users are an interesting population in which to study perceptual learning because they must adapt to electrical hearing. This project examined auditory perceptual learning in normal-hearing adults listening to acoustic simulations of CIs which generated spectrally degraded speech modeled after the input of CIs. Three pre-test/post-test experiments were conducted to determine feedback and semantic effects on perceptual learning and to examine generalization and transfer of learning to frequency shifts, sound identification, and speaker and gender discrimination. Experiment I indicated that learning is rapid and robust when feedback reinstates the original conditions of learning by pairing spectrally degraded sentences with written text. This experiment also found a benefit of training listeners with anomalous sentences. Listeners may have benefited from this training because they were forced to rely on fine acoustic-phonetic cues instead of top-down processing to identify speech. Experiment II found that listeners generalized learning to small frequency shifts and showed some encoding specificity that was dependent on the shift received during training. Experiment III found some evidence of transfer of learning to environmental sound identification in listeners trained with degraded speech. Learning did not transfer to speaker-gender and speaker discrimination. These tasks were not transfer-appropriate because they rely on frequency and formant cues instead of spectro-temporal information available in the degraded speech. The results of these studies have theoretical implications for how normal-hearing listeners learn to perceive degraded speech. This research also has clinical application to CI users who frequently struggle to recognize speech through their devices.
Improving speech reception in noise for cochlear implant users
Ray Goldsworthy, PhD
Program in Speech and Hearing Bio-Sciences and Technology
Harvard University and Massachusetts Institute of Technology
My approach towards developing advanced signal processing algorithms is grounded in psychoacoustics and physiology. The advanced algorithms that I develop incorporate many of the processes that occur in normal hearing that are reduced, or entirely absent, in cochlear implant users. Among these processes are binaural analysis, efferent feedback mechanisms, enhanced spectral resolution and adaptive compression. My research towards incorporating these processes has resulted in algorithms that have successfully improved speech reception in noise for cochlear implant users. I have developed a computational model that quantifies the relative intelligibility of an acoustically degraded and/or processed speech signal for cochlear implant users. This model has shown to successfully predict speech reception trends for different types and levels of additive noise, for reverberation, for various noise reduction algorithms, and for the N-of-M algorithm currently employed in many implant sound processors. The power of the speech reception model is that it allows for a preliminary scan of thousands of algorithm parameters in conjunction with different acoustic environments. Algorithm development and preliminary evaluation is therefore efficient and consistent. Such power is requisite for advancing signal processing for cochlear implants and hearing aids in the future since these systems will necessarily integrate different algorithms and compression strategies. An accurate model of speech reception will allow for preliminary assessments and for hypotheses to be developed that assist in characterizing how these advanced systems interact with diverse acoustic environments. This approach provides a comprehensive framework that allows multiple research teams to work together in order to jointly optimize complex systems.
Developmental implications of infant vocalizations
Mary K. Fagan, PhD
School of Psychology
Cardiff University
The order of acquisition of speech sounds in infancy has been well documented. What is less well documented is growth in number of sounds per utterance and associated changes in duration and number of repetitions per utterance during the first year of infancy. Documenting change in parameters of vocalization in relation to age and the milestones of language development may contribute to our understanding of speech development and the timing of changes in speech production in comparison to other developmental events. Data will be presented from a longitudinal study investigating change in the characteristics of infant vocalization between 3 months and the onset of word production. Change in the parameters of vocalization will be discussed in the context of hypotheses regarding vocalization and exploration and the development of auditory-motor representations before word comprehension and production.
Within-category information is used in language learning and understanding: Temporal integration at two time scales
Bob McMurray, PhD
Department of Psychology
University of Iowa
Speech perception, like many perceptual issues, is fundamentally a balancing act between the efficiency of discrete, symbolic representations, and the informational richness of graded, continuous information in the signal. While traditional approaches to language have favored of the symbolic, I argue for gradient representations. I will first present evidence that adult listeners are systematically sensitive to within-category detail (that would be discarded by classic accounts), and that this variation affects the computation of word meaning. I will then discuss how such sensitivity may be useful for integrating material over the short time scales of online spoken word recognition. In particular, I shall present evidence that small, continuous can be retained to improve the resolution of previously heard ambiguous segments and to anticipate upcoming detail. In a sense, continuous, partially-ambiguous information is retained until it is useful.
These experiments support a view of speech perception in which the system is exquisitely sensitive to fine phonetic detail and that such detail is helpful in word recognition. This has implications for our understanding of perceptual components of language disorders and I will discuss an ongoing program of research addressing this. It also may profoundly affect thinking on the development of speech perception processes. However, until recently, no studies of infant perception have shown gradient sensitivity to acoustic detail. Thus, I will present a series of experiments demonstrating within-category sensitivity in 8-month-old infants. Finally, I discuss a new computational model of the learning process in which within-category sensitivity plays a crucial role in learning speech categories. An interesting prediction of this model is that over long timescales, the developing system may in fact be preserving ambiguity in the phonetic space. Thus, the slow temporal integration of statistically building speech categories may share common mechanisms with the quick integration of online word recognition.
Infant-directed speech and the development of short-term memory: A dynamic system in early language development
Gerald McRoberts, PhD
Haskins Laboratories
Modern theories of language development tend to rely on either species-specific biological capabilities (e.g., Chomsky, Pinker, etc.), or very general learning mechanisms (e.g., Saffran, Bates, etc.). Both of these approaches tend to deny any significant developmental role for how the language environment is structured, despite increasing evidence that mothers adjust the way the talk to infants as linguistic competence increases over the first two years. This talk will propose a dynamic system in which the structure the infant?s early language environment interacts with the development of important cognitive capabilities that support language acquisition. Evidence will be presented for a dynamic and reciprocal influence between the use of repeated words, phrases and utterances in infant-directed speech and the development of short-term auditory (verbal) memory. It is hypothesized that this system provides a scaffolding for the emergence of important language development milestones, including segmentation of the speech stream, vocabulary development, and the emergence of syntactic categories.
The effects of auditory-visual vowel and consonant trainingon speechreading performance
Carolyn Davis Richie, PhD
Department of Communication Studies
Butler University
Recent work examined the effects of a novel approach to speechreading training using vowels, for normal-hearing listeners tested in masking noise [C. Richie and D. Kewley-Port, J. Acoust. Soc. Am. 114, 2337 (2003)]. That study showed significant improvements in sentence-level speechreading for listeners trained on vowels compared to untrained listeners. The present study examined the effects of combining vowel and consonant training on speechreading abilities. Normal-hearing adults were tested in auditory-visual conditions in noise designed to simulate a hearing loss. Using a monosyllable context, one group of listeners received training on consonants, and another group received training on consonants and vowels combined. A control group did not receive training. All listeners performed speechreading pre- and post-tests, on words and sentences. Comparison with the earlier study showed posttest sentence-level speechreading increased by 10 percentage points for participants in the vowel training program, 8 percentage points for participants in the consonant training program, and, unexpectedly, only 2 percentage points for participants in the combined training program. Results from these relatively short training programs suggest that vowels, previously unused in speechreading training, may provide gains in speechreading abilities and play an important role in habilitation of listeners with hearing loss. (Supported by NIHDCD-02229)
Evidence from auditory brainstem implants of a modulation-specific auditory pathway that is critical for speech recognition
Robert B. Shannon, PhD
Department of Auditory Implants and Perception and
Auditory Implants Research Laboratory
House Ear Institute
Excellent speech understanding has been observed in patients with prosthetic electrical stimulation of the cochlear nucleus. Psychophysical tests reveal that the difference between listeners with high and low speech understanding is not due to overall neuronal survival in the cochlear nucleus, the quality of electrode placement or the specificity of stimulation by individual electrodes, but is related to the ability to detect amplitude modulation. The difference in speech understanding was dramatic between patients whose deafness was caused by vestibular schwannomas on the VIII nerve or from other causes of VIII nerve loss. The relation between etiology, modulation detection and speech recognition suggests that tumor growth and resection has selectively damaged a physiological processing pathway specialized for modulation. This suggests that modulation specialized cells represent a critical pathway for speech recognition and their loss impairs speech recognition even when other cell types survive.
Perceptual and physiologic results in adult cochlear implant recipients
Jill B. Firszt, PhD
Department of Otolaryngology and Communication Sciences
Medical College of Wisconsin
There is wide variation in the speech recognition abilities of individuals who are candidates or recipients of cochlear implants. Although some variables have been identified that contribute to the variance in performance (e.g., length of auditory deprivation, amount of residual hearing), a large percentage remains unexplained. In the auditory cortex, timing, intensity and frequency cues contribute to speech recognition and are represented by cortical neural activity. Although we can assess speech recognition in adult cochlear implant users, much less is known about the underlying physiology in response to electrical stimulation. In children, even less is known.
The study of auditory pathway physiology in humans can be conducted with electrically evoked auditory potentials. The current investigation consisted of two studies. The aim of Study I was to evaluate the effects of stimulus parameters (e.g., stimulus level and electrode site) on electrically evoked auditory potentials. Based on previous studies in animals and humans, it was hypothesized that evoked potential response measures of latency, amplitude and threshold would be affected by stimulus level and electrode site. In addition, if the strength of electrically evoked neural responses (i.e., amplitude) and neural conduction times (i.e., latency) were inadequate, this may affect speech recognition abilities with a cochlear implant. The aim of Study II was to evaluate the hypothesis that lower speech recognition scores would be associated with abnormal physiologic responses at the brainstem and/or auditory cortex in adult cochlear implant recipients.
Study results indicate that in adult cochlear implant subjects, 1) measures of latency, amplitude and threshold are affected by stimulus level and electrode site, and 2) subjects with low speech recognition scores demonstrated poorly formed or absent evoked potential measures, reduced electrical dynamic ranges, and longer periods of auditory deprivation. These findings suggest that 1) stimulation parameters should be controlled in studies that employ electrically evoked potential responses, and 2) neural encoding with electrical stimulation must provide sufficient physiologic responses along the auditory pathway to recognize speech with a cochlear implant. Further research is needed that combines perceptual and physiologic results in cochlear implant recipients. Supported by NIH/NIDCD K23DC05410.
Production and perception of clear speech
Ann R. Bradlow, PhD
Department of Linguistics
Northwestern University
When a talker believes that the listener is likely to have speech perception difficulties due to a hearing loss, background noise, or a different native language, he or she will typically adopt a listener-oriented, intelligibility-enhancing speaking style known as "clear speech." To the extent that clear speech is more intelligible than "conversational speech," an acoustic-phonetic comparison of these two speaking styles provides unique information about factors that affect speech intelligibility. In this talk, I will present new data from a project that was designed to test the hypothesis that naturally produced clear speech is guided by both universal, auditory-perceptual factors and language-specific structural factors. The universal, auditory-perceptual factors serve to enhance the overall acoustic salience of the speech signal such that it is more resistant to the adverse effects of environmental noise or listener-related perceptual deficits, while the language-specific structural factors serve to enhance the realization of phonologically important contrasts. Two important predictions of this hypothesis are (a) clear speech production will show predictable and systematic similarities and differences across languages, and (b) the intelligibility benefit of naturally produced clear speech will be greater for listeners with well-entrenched knowledge of the sound structure of the target language than for listeners with limited experience with the sound structure of the target language. In order to address these predictions, I will present data from a cross-language comparison of clear speech production and a cross-population comparison of clear speech perception. Taken together, these studies provide fundamental information about sources of variability in speech intelligibility and should ultimately allow us to devise effective, efficient and scientifically-grounded speech intelligibility enhancement strategies that are customized to particular listener populations.
Spoken language development in two newer populations of cochlear implant recipients: Children with cognitive delays and children with residual hearing using hearing aids in their nonimplanted ears
Rachael F. Holt, PhD
Department of Otolaryngology-Head and Neck Surgery
Indiana University School of Medicine
Changes in cochlear implant (CI) candidacy criteria have resulted in more inclusive guidelines than ever before. Currently, children as young as 12 months of age with profound hearing loss and those with severe-to-profound hearing loss who are 24 months of age or older are eligible for cochlear implantation. Children with additional disabilities are excluded from FDA clinical trials, but have been implanted with FDA-approved devices. Two investigations were carried out to examine the speech and language development of two groups of pediatric CI recipients that have emerged with these broadening candidacy criteria: children with mild cognitive delays and children with residual severe hearing loss in their nonimplanted ears, some of whom have continued hearing aid (HA) use in their nonimplanted ears. In the first study, we retrospectively examined the speech and language development of two groups of CI users with pre-lingual deafness: children with cognitive delays and no other disabilities (n=19) and children without cognitive delays or any other identified disability (n=50). Both groups demonstrated significant improvement in their speech and language skills over time on every test administered. There were no significant group differences in auditory-only or multimodal word recognition. Children with cognitive delays had significantly lower scores than typically developing children on two of the three measures of receptive and expressive language and had significantly slower rates of auditory-only sentence recognition development. In the second study, two groups of pediatric CI recipients, one with profound hearing loss (n=124) and one with severe hearing loss (n=22) in their nonimplanted ears, were tested longitudinally on a battery of spoken word recognition and language measures. A subgroup of children with severe hearing loss that continued HA use in their nonimplanted ears (n=10) were assessed longitudinally on spoken word recognition measures in quiet and background noise using their CIs alone, HAs alone, and CIs in conjunction with HAs. Although children with different degrees of residual hearing had improved speech recognition and language skills after cochlear implantation, the developmental time course differed for the two groups: children with severe hearing loss required more than 1 year of CI experience to demonstrate spoken word recognition gains, whereas children with profound hearing loss showed more benefit during the first year after cochlear implantation. For measures in which group performance differed, children with severe hearing loss had better speech recognition and language skills than children with profound hearing loss. Furthermore, children with severe hearing loss who continued using HAs in their nonimplanted ears benefited from combining the acoustic input received from a HA with the input received from a CI, particularly in background noise. However, this benefit emerged with experience. These findings suggest that: 1) children with mild cognitive deficits be considered for cochlear implantation with less trepidation than has been the case in the past; 2) it is appropriate to encourage pediatric CI recipients with severe hearing loss to continue wearing an appropriately fitted HA in the nonimplanted ear to maximally benefit from bilateral stimulation.
2004
Perceptual dialect classification:Some effects of residential history and hearing impairment
Cynthia Clopper, PhD
Department of Psychology
Indiana University
Research on the perception of dialect variation has traditionally focused on attitudinal judgments of variation based on long-term memory representations instead of behavioral responses to speech stimuli. However, a growing body of research in the speech sciences has shown that indexical information affects the speech perception and processing in normal-hearing and hearing-impaired populations. A series of experiments was conducted in which participants were asked to listen to sentence-length utterances produced by speakers from multiple different parts of the United States and classify each talker by regional dialect in a six-alternative forced-choice categorization task. In Experiment 1, normal-hearing young adults categorized male and female talkers from six different regional varieties of American English with 32% accuracy. A clustering analysis of the errors they produced revealed systematic confusions due to phonological similarities between the different varieties. In Experiment 2, four groups of normal-hearing young adults who differed in their residential history performed a similar categorization task. The four groups were Mobile Northerners, Mobile Midlanders, Non-Mobile Northerners, and Non-Mobile Midlanders. While no overall differences in accuracy were found based on residential history, the results of a clustering analysis of the errors revealed consistent differences in perceptual similarity of the dialects due to both region of origin and geographic mobility, suggesting that linguistic experience with different dialects shapes representations of linguistic variation. Finally, in Experiment 3, a post-lingually deafened adult CI user, "Mr. S," completed the categorization task with accuracy levels within one standard deviation of the young normal-hearing listeners in Experiment 1, suggesting that he was also able to use dialect-specific information in the speech signal in an explicit categorization task. Taken together, these results provide further evidence for the important role of indexical information in spoken language processing for both normal-hearing and hearing-impaired populations.
Why are verbs so hard for young children to learn?
Roberta Golinkoff, PhD
School of Education and Departments of Psychology and Linguistics
University of Delaware
Verbs are the architectural centerpiece of the sentence. They allow us to talk about the relations that hold between the entities in our world and say who did what to whom. Yet there is a paradox surrounding verb learning. While children have some verbs in their earliest vocabularies, verbs are very difficult for children to learn. This talk first, presents data on this paradox and second, suggests an explanation for it, based in factors relevant to the child's cognitive development and the language itself.
Social-emotional profiles of toddlers with autism, developmental delay, and typical development
Julia Irwin, PhD
Haskins Laboratories
Increased interest in early detection of autism spectrum disorders has heightened knowledge about early signs of autism. However, little is known about non-core autism social-emotional problems and competencies that may affect both developmental course and family experience. The focus of this talk is on both autism symptomatology and co-occurring social-emotional and adaptive behaviors in a sample of toddlers later diagnosed with autism. Mental-age matched groups of developmentally delayed (DD) and typically developing (TD) children allowed an assessment of whether autism is associated with: 1) an increased risk for specific patterns of social-emotional problems; or, 2) delays in the acquisition of competencies.
Spectral shape discrimination ability using cochlear implants
Ward R. Drennan, PhD
Kresge Hearing Research Institute
Listeners were asked to detect a current increment to one of 1, 3, 7, 11 and 21 active electrodes. Sensitivity to differences in the electric profile decreased with increasing number of electrodes. This is probably the result of current interaction and masking effects. It is proposed that electric profile discrimination provides an excellent measure of channel interaction using a practical stimulus. In a second experiment, the effects pulse rate and electrode spacing on electric profile discrimination were evaluated using clinically common parameters and a 7-active-electrode profile. Results were highly variable among listeners.
Trends suggest that high pulse rates sometimes lead to greately decreased spectral-shape sensitivity. Listeners often had best sensitivity at their clinical pulse rate. In a third experiment, listeners' ability to hear a change in a 7-active-electrode profile was studied in which the overall level was roved by 0, 10 and 20% of the dynamic range within individual trials. One of four listeners was able to discriminate electric profile changes smaller than the amount of the rove.
"I didn't really hear everything I heard": A child's perspective on hearing and listening in the real world
Fred Wightman, PhD
Department of Psychological and Brain Sciences
University of Louisville
Attending to a target speech message in the presence of background noise is a problem all of us face every day. Research shows that when the interference is speech, the task can be especially difficult as a result of an effect called "informational masking". Informational masking is masking that cannot be explained on the basis of traditional filter-bank models of auditory processing, and occurs in part because the masker is either similar to the target or is uncertain. Informational masking effects are much greater in children, leading to speculations that a normal classroom environment might pose extraordinary challenges for speech understanding in children. Our research quantifies these effects in psychophysical tasks that the children find interesting and also examines the role of combined auditory and visual information about the target speech message. Recent pilot tests of children with cochlear implants suggests that at least some of the implanted children perform exactly like normally hearing children, at least on these tests.
The acquisition of syntax: The role of phrase segmentation
Amanda Seidl, PhD
Department of Audiology and Speech Sciences
Purdue University
An important aspect of acquiring a natural language is discovering the relevant syntactic units in the input language. If syntax influences prosody (e.g., Bresnan, 1971; Chomsky & Halle, 1968; Selkirk, 1994), then information in the speech stream may help learners discover the syntactic units of their language and subsequently the syntactic structure of their input language (Gleitman & Wanner, 1982).
The syntactic phrase is a particularly important unit in language acquisition, because it contains more language specific information that the clause. For example, information about word order can be gleaned from the phrase based on the prosodic prominence relationship between heads and complements within this unit (Nespor, Guasti and Christophe, 1996), e.g., a verb is less prosodically prominent that its direct object. Thus segmentation of the phrase from continuous speech should prove particularly useful. In this talk, I suggest that the segmentation of phrases from continuous speech is a prerequisite for language specific syntactic competence and I present two experiments that explore infants' segmentation of both verb and noun phrases.
After familiarization with two versions of the same word sequence as a noun phrase and non-noun phrase, 6-month-olds showed a preference for a passage containing the sequence as a noun phrase over a passage with the same sequence as a syntactic non-unit. However, this result was found only in one of two groups, the group exposed to a stronger prosodic difference between the syntactic and non-syntactic sequences. Six-month-olds were tested in the same way on passages containing verb phrases. In this case, both groups preferred the passage with the verb phrase to the passage with the same word sequence as a syntactic non-unit.
These results provide the first evidence that infants as young as 6 months of age are sensitive to prosodic markers of syntactic units smaller than the clause and thus posses an important piece of knowledge crucial to learning language specific syntax. In addition, it shows that infants can use this sensitivity to segment fluent speech into phrasal units, both noun and verb phrases. This ability to use phrasal cues is variable, however, and appears to depend on the strength of the cues associated with the syntactic unit. These findings will be discussed in reference to recent findings concerning infants' sensitivity to specific prosodic cues.
Adaptive behavioral assessment of pre-lingually deaf children with cochlear implants
David Horn, MD
Department of Otolaryngology-Head and Neck Surgery
Indiana University School of Medicine
Many pre-lingually deaf children obtain significant gains in oral language skills with a cochlear implant (CI) although significant individual differences in audiological outcomes are widely reported. A number of investigators have found evidence that some of this variation in reflects underlying individual differences in cognitive development. Recent studies of deaf children with CIs have demonstrated relations between outcome measures and several cognitive skills including verbal encoding, visual memory, and audiovisual integration. Few studies, however, have attempted to examine the predictive value of measures of cognitive developmental functioning in deaf children on abilities that emerge over several years of CI use.
We conducted a retrospective analysis of data from 42 pre-lingually deaf children who received a cochlear implant, on average, by about 5 years old. Cognitive development was assessed prior to CI surgery in each subject using the Vineland Adaptive Behavioral Scales (VABS), a standardized parental checklist of behaviors that cover a wide range of behavioral domains spanning early infancy through late childhood. Separate standard scores are obtained for motor development, daily living skills, and socialization skills. Several audiological tests were administered to each child at 6-month intervals after CI activation over 3 years of CI experience. These tests assessed speech perception, speech intelligibility, language, and vocabulary knowledge.
In order to assess whether adaptive behavioral functions were developing typically in our sample of pre-lingually deaf children, we computed correlations between chronological age at VABS assessment and each domain scaled score. While socialization, daily living skills, and adaptive behavioral scores were strongly and negatively correlated with age (p<0.01), motor development was related to age suggesting that motor development alone was developing typically in these young deaf children. This conclusion was supported by comparing the mean scaled scores of each VABS domain as the mean motor score was significantly greater than each of the other domain means.
For each VABS domain, we constructed a statistical model to analyze effects on the audiological outcome measures. VABS score and chronological age at VABS test were between subjects variables, while length of CI use was the repeated measures variable. We found a pattern of main effects and interactions indicating that the VABS motor score was a significant pre-implant predictor of CI outcomes in children. No predictive effects were found for any of the other VABS domains.
There are a number of reasons why the socialization and daily living skills domains may not accurately reflect emergent cognitive abilities of profoundly deaf children. First, early auditory deprivation may lead to atypical development of these skills which is overcome after access to sound is established through a CI. Secondly, the checklist items which produce the socialization and daily living scores may be insensitive to or biased against the adaptive skills which develop in deaf children. In contrast, the motor domain score was did not show a negative relationship with chronological age and appears to be sensitive to individual differences in underlying perceptual-motor skills which play a significant role in acquiring auditory and language skills with a CI. Work supported by NIH/NIDCD grants R01DC00064, R01DC00423, and T32DC00012 to Indiana University.
The impact of neural adaptation upon temporal integration abilities as measured in Nucleus 24 cochlear implant recipients
Marcia Hay-McCutcheon, MA
Department of Speech Pathology and Audiology
University of Iowa
This presentation will focus upon the relationship between peripheral neural adaptation and temporal integration as measured in Nucleus 24 cochlear implant recipients. It is hypothesized that the degree of adaptation observed at the level of the peripheral auditory system will have an influence upon the degree of temporal integration observed within the central auditory system. Neural adaptation was measured by tracking amplitude changes of the Electrical Compound Action Potential (ECAP) to varying lengths of rapid rate biphasic pulse trains. Temporal integration was assessed through the use of a loudness balancing procedure and through the use of two threshold measures. Results suggest that while both neural adaptation and temporal integration varying within and across individuals, the degree of neural adaptation has little influence upon temporal integration abilities in cochlear implant recipients. Implications of this study, along with future research directions, will be discussed.
Deprivation, development and plasticity of the human central auditory pathways
Anu Sharma, PhD
Callier Center for Communication Disorders
The University of Texas at Dallas
We are investigating the development, deterioration and plasticity of the human central auditory pathways in normal hearing children, hearing impaired children and children with cochlear implants. Our measure of central auditory maturation are cortical auditory evoked potentials (CAEPs). Previously we have reported that there is a sensitive period of 3.5 years during which the central auditory pathways remain maximally plastic in the presence of congenital deafness. Congenitally deaf children who are implanted within this sensitive period show rapid changes in CAEP latency within the first few months following implantation. Congenitally deaf children implanted after age 7 years show little central auditory development even years after implantation. Our studies on children with acquired deafness demonstrate that a brief period of normal hearing prior to deafness does not preserve the plasticity of the central auditory pathways or extend the duration of the sensitive period. On the other hand, hearing that deteriorates gradually is a more effective insulator of the plasticity of the central auditory pathways. That is, children who show progressive hearing losses are likely to benefit from a cochlear implant even when fitted at a late age. We will discuss how cochlear implantation at a very young age and bilateral cochlear implantation may have a further impact on the plasticity of the central auditory pathways. In other studies, we are examining whether early implanted children who show normal CAEP latencies also show age appropriate results on more complex aspects of auditory system development such as maturation of neuronal refractoriness of cortical generators.
We are cross-validating CAEP measures of central auditory development with measures of speech production in children with hearing impairment and cochlear implants. Preliminary data indicate that the development of early communicative behaviors following implantation may be positively conditioned by the rate of plastic changes in central auditory pathways.
We find that CAEPs are powerful, objective markers of central auditory system plasticity and maturation. CAEPs may serve as much needed clinical indicators of central auditory development in infants and young children who receive intervention through conventional amplification, cochlear implants or a combination of the two technologies.
The development of intersensory perception: The importance of intersensory redundancy
Lorraine E. Bahrick, PhD
Department of Psychology
Florida International University
Our senses provide overlapping, redundant information for objects and events in the environment. This overlap facilitates attention to critical aspects of sensory stimulation, those that are redundantly specified, and attenuates attention to nonredundantly specified stimulus properties. According to our intersensory redundancy hypothesis (IRH; Bahrick & Lickliter, 2000, 2002), this selective attention is most pronounced in infancy and gives initial advantage to the perceptual processing, learning, and memory for stimulus properties that are redundant or "amodal" (e.g., synchrony, rhythm, tempo, and intensity) at the expense of "modality specific" properties (e.g., color, pattern, pitch, and timbre) that can be perceived through only one sense. I review evidence from our program of research supporting this hypothesis and discuss its implications for theories of development. Further, I discuss possible consequences for the congenitally deaf and make predictions about likely effects of restored auditory functioning through cochlear implants on perceptual organization and intersensory functioning.
Children's auditory research at the House Ear Institute: Overview and new directions
Laurie Eisenberg, PhD
House Ear Institute
The Children's Auditory Research and Evaluation (CARE) Center at the House Ear Institute is a fully functioning audiology clinic and research laboratory for children. An overview of the clinical and scientific activities that generally take place in the CARE Center is presented, including a discussion about how the two areas are integrated in conducting applied research with a clinical population. Present and future research endeavors in the CARE Center cover the following two broad areas: 1) development of human auditory function, and 2) auditory perceptual development of children with hearing loss. New directions in research are dedicated to the development and refinement of novel assessment tools for measuring auditory-perceptual capacity in young children. One such test, the On-line IMSPAC, assesses the child's ability to convey phonologically significant information through the imitation of consonant-vowel stimuli. This test has been successfully administered to children 2-3 years of age. Preliminary results indicate that age effects are minimal and the test is sensitive to degree of hearing loss.
Development of sustained visual attention in prelingually deaf children with cochlear implants
David Horn, MD, and Rebecca A.O. Davis, BS
Department of Otolaryngology-Head and Neck Surgery
Indiana University School of Medicine
In prelingually deaf children, cognitive development proceeds in the absence of auditory input. Auditory deprivation has been shown to affect not only the auditory pathways, but the visual pathways as well. Pediatric CI users, a unique clinical population who have had auditory input restored after a period of near total deprivation, can tell us a great deal about how auditory stimulation guides the development of visual processes. Several studies have measured sustained visual attention in deaf children who use cochlear implants (CIs) and report an interaction between age and cochlear implantation: deaf children who use CIs display greater age-related gains in sustained visual attention than deaf children who do not use implants. The effect of cochlear implantation on sustained visual attention has been hypothesized to be rapid and independent of speech and language gains which emerge over many years of CI use. However, previous studies have not controlled for length of CI use, nor have relations between sustained visual attention and speech and language outcomes been examined. Moreover, earlier research has not assessed the effects of surgical, audiological, and demographic factors on sustained visual attention in pediatric CI users are unknown.
We conducted a retrospective analysis of longitudinal data obtained from prelingually deaf children prior to implantation and over 2 years of CI experience. Sustained visual attention was measured using a Continuous Performance Task (CPT): a computerized visual attention task in which children are asked to monitor a string of visual stimuli and to press a key only when a target stimulus appears. This task is a routine clinical test used to assess impulsivity and inattention in children being evaluated for Attention Deficit Hyperactivity Disorder. In addition, 7 standard audiological outcome measures obtained after 1 year of implant use were compared to CPT scores.
Independent measures included pure tone average, number of active electrodes, etiology of deafness, device type, ear of implantation, gender, communication mode, age of implantation, and length of CI use. Our analyses revealed independent positive effects of both age of implantation and length of CI use on CPT scores. We found that CI use over a two year period, independent of chronological age, facilitated improvement in sustained attention skills. We also found a significant effect for number of active electrodes on visual attention skills. Children who used over 20 electrodes had superior sustained visual attention skills than children who used fewer electrodes. Finally, we examined correlations between speech and language skills and CPT scores 1 year after implantation and found no significant relations. Our findings support earlier studies suggesting that visual attention gains in pediatric CI users occur relatively rapidly over two years of CI use. Moreover, these gains are independent of speech and language acquisition at least at the early post-implant year examined.
2003
Cognition, personality, and genotype/phenotype correlations in Williams Syndrome
Carolyn B. Mervis, PhD
Department of Psychological and Brain Sciences
University of Louisville
Williams syndrome is a neurodevelopmental disorder caused by a microdeletion of at least 19 genes on the long arm of chromosome 7 (7q11.23). The syndrome is characterized by mild to moderate mental retardation or learning difficulties, accompanied by an unusual cognitive profile including relative strength in verbal short term memory and language and extreme weakness in visuospatial constructive cognition (e.g., writing, drawing, pattern construction). Williams syndrome also is associated with an unusual personality profile including gregariousness, overfriendliness, high levels of empathy, and anxiety. By studying individuals and families who have partial deletions of 7q11.23, my research group has been able to identify two genes that are associated with phenotypic characteristics of Williams syndrome. I will present an overview of our research on cognition and personality in Williams syndrome and what we have learned about the genetic underpinnings of this syndrome.
Multisensory perception and language development in infancy
Lakshmi J. Gogate, PhD
Department of Psychiatry
State University of New York Health Science Center at Brooklyn
The relationship between developing auditory-visual perception and early receptive language development will be discussed with special emphasis on the salience of temporal synchrony for learning word-world links during the first year.
Audiovisual asynchrony detection for speech and nonspeech signals
Brianna Conroy
Department of Psychology
Indiana University Bloomington
Temporal correlation of auditory and visual stimuli is known to be critical in producing audiovisual (AV) enhancement (Stein & Meredith, 1993). Investigations of the temporal limitations of AV enhancement are therefore important to our theoretical understanding of AV processing. Desynchronizing auditory and visual inputs is one tool that can be used to conduct such investigations.
Participants were asked to judge whether various AV speech and nonspeech signals were synchronous. Over an 800-msec range of AV asynchronies, the video-leading threshold for asynchrony detection was larger than the audio-leading threshold, replicating previous findings reported in the literature. Although the audio-leading threshold did not differ for any of the stimulus sets, the video-leading threshold was significantly larger for the point-light display (PLD) condition than for either the full-face (FF) or nonspeech (NS) conditions. In addition, a small but reliable phonotactic effect of visual intelligibility was found for the FF condition. High visual intelligibility words produced larger video-leading thresholds than low visual intelligibility words. Relationships with recent neurophysiological data on multisensory enhancement and convergence will be discussed. Also, a case study of a cochlear implant user performing the AV asynchrony detection task will be presented.
Recent and remote episodic and semantic memory: Consolidation and hippocampal-neocortical interactions
Morris Moscovitch, PhD
Rotman Research Institute and Department of Psychology
University of Toronto
Recent and remote episodic and semantic memory: Consolidation and hippocampal-neocortical interactions It has long been believed that remote memories are spared in amnesia, leading to the idea that the hippocampus and related structures in the medial temporal lobes act as temporary memory systems, needed only until memories are consolidated in neocortex and other regions of the brain. To test this idea, evidence will be presented from behavioural studies of remote autobiographical and semantic memory in people who are amnesic or demented, and from neuroimaging studies in normal people. The results of these studies indicate, contrary the standard consolidation memories of autobiographical edpisodes for as long as the memories exist. Semantic memories and the gist of autobiogrpahical episodes, however, can be retained and retrieved without the hippocampal system. Time permitting, data from rats will also be presented to show that differences exist even in rats between memories that are context-dependent (episodic) and context-free (semantic). A multiple trace theory of hippocampal-neocortical interaction is proposed to account for the data.
The linguistic construal of space: The perspective from cognitive neuroscience, with a nod toward developmental issues
David Kemmerer, PhD
Department of Audiology and Speech Sciences and Department of Psychological Sciences
Purdue University
This talk is about the relation between the meanings of English prepositions (e.g.., in, on, above, below) and the kinds of mental representations that are used fro many visuospatial processes such as recognizing, drawing, and constructing spatially complex objects. One possibility that has been proposed by some psycholinguists is that the meanings of prepositions are the same as the representations used in these other processes. An alternative possibility, which has been proposed by a different group of researchers, is that the relation is more distant such that the meanings of prepositions constitute language-specific semantic structures that are distinct from the representations that underlie many visuospatial abilities.
I report a detailed assessment of the linguistic as well as perceptual and cognitive representations of spatial relationships in two brain-damaged subjects. Four tests were administered that require production, comprehension, and semantic analysis of English locative prepositions. In addition, four standardized neuropsychological tests that probe high-level nonlinguistic visuospatial perception and cognition were administered. Case 1 was significantly impaired on all of the preposition tests but was normal on all of the visuospatial tests. In striking contrast, Case 2 was normal on all of the preposition tests but was significantly impaired on all of the visuospatial tests. The subjects also had entirely different brain lesions: Case 1 had a left-hemisphere lesion in the frontoparietal region, and Case 2 had a right-hemisphere lesion in the frontoparietal and temporal regions. Together, the results constitute a "double dissociation," suggesting that the preposition tests and the visuospatial tests require cognitively and neurally distinct mechanisms that can be disrupted independently of each other. I interpret the data as supporting the second possibility described above-namely, that the meanings of locative prepositions may be language-specific semantic structures that are separate from the mental representations underlying many other kinds of high-level nonlinguistic visuospatial abilities.
If time permits, more recent PET and lesion data will be presented which suggest that the meanings of locative prepositions are subserved by the left anterior supramarginal gyrus.
Developmental issues will be touched on at various points during the talk (mainly in the context of extensive crosslinguistic variation in the coding of spatial relationships), and could easily become a topic of discussion afterward.
Gradual adaptation to shifts in the peripheral acoustic frequency map
Mario Svirsky, PhD
Department of Otolaryngology-Head and Neck Surgery
Indiana University School of Medicine
It is generally accepted that cochlear implants (CIs) impose a basalward shift to the acoustic input, that is, sounds stimulate neurons with higher characteristic frequency than the acoustic frequency of the original stimulus. This frequency misalignment may have a negative influence on speech perception by CI users. However, a perfect frequency-place alignment may result in the loss of important low frequency speech information. A trade-off may involve a gradual approach: start with correct frequency-place alignment to allow listeners to adapt to the spectrally degraded signal first, and then gradually increase the basalward shift to allow them to adapt to it over time. Two pairs of normal hearing listeners underwent 15 hours of speech perception training and testing using a real-time acoustic model of a CI. This 8-channel model simulated a 6.5 mm basalward shift. Subjects were randomized either to the "gradual" group (where the 6.5 mm basalward shift was introduced gradually over the course of ten sessions) or to the "fixed" group, who were exposed to the full 6.5 mm shift since the beginning. Both groups underwent 15 1-hour sessions using audiovisual speechtracking as well as vowel, consonant and sentence recognition tests. For the second pair of subjects, three fMRI recordings were conducted at the beginning, middle and end of the study to assess changes in cortical activation in response to the CI acoustic simulations with 6.5 mm shift. Speech perception scores were initially much higher for the "gradual" group, but by the end of the 15 sessions the "fixed" group had almost caught up with them. Imaging results suggest that the behavioral adaptation shown by increasing speech perception scores was paralleled by increases in cortical activation of language areas. Taken together, these results suggest that gradual exposure to basalward shift may result in faster speech perception improvement by CI users.
Interactions between rhythmic motor sequences and prosodic categories in normal and disordered language development
Lisa Goffman, PhD
Department of Audiology and Speech Sciences
Purdue University
A central aim of this research is to determine how linguistic intentions are instantiated in motor action. Language is expressed through movement and a major developmental task is to link motor output patterns with emerging linguistic representations. In the view presented here, movement implementation is not separate from linguistic levels of processing, but there is a complex interface between language and motor processes. Developmental change occurs as communicative demands become increasingly complex and specified and the motor system is required to move beyond its preferred state to implement new distinctions. These studies incorporate kinematic analyses of rhythmicity and variability to investigate how children and adults produce prosodic (e.g., iambic vs. trochaic) distinctions in their movement output. Of particular interest is how motor skill links with linguistic representation in children with specific language impairment, since both motor and language deficits have been implicated for these children.
