Skip to main content

Abstracts and Presentations

2002 CAS Research Symposium

Abstracts of Presentations

Childhood Apraxia of Speech
Research Symposium

Symposium Co-sponsored by the Bruce and Patricia Hendrix Foundation and the Childhood Apraxia of Speech Association

Apraxia of Speech: Historical Overview and Clinical Manifestations of the Acquired and Developmental Forms.

Joseph R. Duffy, Ph.D., BC-NCD
Mayo Clinic, Rochester, MN

This presentation will review the historical development of clinical concepts, definitions, and descriptions of apraxia of speech (AOS). The features shared by the adult-acquired and childhood forms will be emphasized, especially those that may represent diagnostic markers. Videotape samples of people with AOS will serve as a vehicle for demonstration and discussion.

Clinical Characteristics of AOS: Model/Behavior Coherence

Malcolm R. McNeil, Ph.D. BC-NCD
University of Pittsburgh

This presentation will review the relevant literature from adults with apraxia of speech (AOS) and the models that have been proposed to account for these behaviors. Two models will be reviewed in detail that account for specific speech production behaviors at the phonological encoding, motor planning, motor programming and motor execution levels. The “traditional” characteristics describing AOS will be compared to these models and a reassignment of AOS behaviors that are coherent with both the observed behaviors and the models will be presented. From this, a set of behaviors that are necessary for the diagnosis of AOS in children will be presented.

From Genes to Brain and Behaviour: The KE Family and the FOXP2 Gene

Faraneh Vargha-Khadem, Ph.D.
University College London

Half the members of the KE family are affected by a severe verbal dyspraxia, which results from a mutation of the FOXP2 (SPCH1) gene. A series of studies will be reported to establish the behavioural phenotype of this disorder, and its associated brain abnormalities as indicated through structural and functional brain imaging techniques.

Childhood Apraxia of Speech: Clinical Symptoms and Speech Characteristics

Thomas F. Campbell, Ph.D. BC-NCD
University of Pittsburgh

Among the plethora of diagnostic markers presumed to be associated with apraxia of speech, abnormal temporal separation of speech sounds and syllables has often been mentioned as a hallmark characteristic of the disorder. In this paper, intersyllabic timing profiles of individual children with and without apraxia of speech will be presented. Results will be discussed in terms of current models and potential underlying mechanisms of apraxia of speech in children.

Speech and Non-Speech Motor Performance Profiles as Diagnostic Markers in CAS

Michael A. Crary, Ph.D.
University of Florida Health Science Center

This presentation will put forth two main points: 1) children considered to demonstrate CAS will present with impaired motor speech and non-speech (oral) voluntary motor performance compared to controls; and 2) different patterns of motor performance suggest different forms of “apraxic impairment”. Relationships among motor speech, non-speech motor, and speech articulation performances will be discussed.

Patterns of Vowel Production in Childhood Apraxia of Speech

Barbara Davis, Ph.D.
University of Texas-Austin

Vowels have frequently been mentioned as potential differential diagnostic markers for childhood apraxia of speech. Few studies describe differences in vowel use in detail. In-depth analyses of vowel inventories and error patterns are important to understanding valid clinical diagnostic markers and to theory building for this complex disorder category.

The Contribution of EPG to the Diagnosis of Childhood Apraxia of Speech

Fiona Gibbon, Ph.D.
Queen Margaret University College, Edinburgh

This paper discusses the contribution that articulatory data gathered using the technique of electropalatography (EPG) can make to the diagnosis of childhood apraxia of speech. Abnormal articulatory behaviors, such as undifferentiated tongue gestures, will be described and compared to similar gestures found in the speech of adults with acquired apraxia.

Some Speech Assessment Findings in Suspected Apraxia of Speech

Lawrence Shriberg, Ph.D.
University of Wisconsin-Madison

This report is an overview of findings from three collaborative study series of children with suspected apraxia of speech, conducted during the past 5 years. The focus is on perceptual and acoustic speech assessment findings, including a discussion of classification and misclassification issues from a recent study of speech samples from 110 speakers.

An Argument for Focusing on the Relative Contribution of Processing Deficits

Edythe Strand Ph.D. BC – NCD
Mayo Clinic, Rochester, MN

This paper will posit the use of several specific diagnostic markers toward determining the CAS phenotype. Frequency and severity of these markers may vary with age and linguistic development. An argument will be made for reporting the relative contribution of cognitive, linguistic, and motor deficits.

VMPAC and PEPS: Effective New Tools for Differential Diagnosis?

Shelley L. Velleman, Ph.D.
University of Massachusetts at Amherst

Deficits in oral-motor and speech sequencing skills and prosody have long been regarded as important indicators of childhood apraxia of speech. Preliminary results from two new diagnostic tests (the Verbal Motor Production Assessment for Children and Profiling Elements of Prosodic Systems) will be presented for 10 children with possible CAS.

An Epidemiologic Perspective of Childhood Apraxia of Speech

Bruce Tomblin, Ph.D.
University of Iowa

Epidemiology uses observational methods for the study of the distribution of diseases in populations in order to inform theories of taxonomy and etiology of diseases. This presentation will examine the kinds of research questions and research designs used in epidemiology and their application to research on childhood apraxia of speech.

Genetic Analyses of Complex Behavioral Phenotypes: Cognitive Components and Comorbidities

Bruce F. Pennington, Ph.D.
University of Denver

This talk will illustrate the lessons we have learned about the close reciprocal relation needed between phenotypic and genotypic analyses of complex behavioral disorders, based on over 20 years of work on developmental dyslexia. Molecular work on this disorder is proceeding rapidly and is testing which genes contribute to which cognitive components and comorbidities.

Magnetic Resonance Imaging of Motor Function and Dysfunction

Steven Small, MD, Ph.D.
University of Chicago

Functional magnetic resonance imaging (fMRI) can demonstrate areas of the brain active during motor behavior, including motor speech. In this talk, I will discuss the potential usefulness of fMRI techniques for studying motor function of the brain in the normal state and in the context of neurological perturbations and change.

Speech Motor Development: An Interactive, Multiple Component Account

Anne Smith, Ph.D.
Purdue University

Typically developing children seem to acquire speech motor skills effortlessly; however speaking requires the control and coordination of activity in cognitive, emotional, linguistic, and motor systems. These generally have been treated as separate processing steps. This presentation will focus on the potential interactions among these systems and the ways in which these interactions can be studied in young children.

Physiologic Development of Speech: Implications For Children With Developmental Speech Impairment

Christopher A. Moore, Ph.D.
University of Washington-Seattle

This presentation will summarize a broad array of experimental results in developmental speech physiology. Empirical studies of adults and of children who are developing typically will be discussed to provide a framework for the study of developmental speech impairment. Ongoing experiments with a large population of children with nonspecific speech impairment will also be described.

Acoustic Methods for the Study of Speech Motor Dysfunction

Ray D. Kent, Ph.D.
University of Wisconsin-Madison

The acoustic signal is at once the end product of speaking and the raw material for speech perception. Methods of acoustic analysis are described to identify impairments at the levels of discourse, phrase, word, syllable, and segment — all within the framework of a physiologic – acoustic – perceptual linkage.

Cognitive-Neuropsychological Approaches in Speech Motor Disorders in Children

Ben Maassen, Ph.D.
University Medical Center St.Radboud
Nijmegen, The Netherlands

‘Pure’ childhood apraxia of speech (CAS) is an infrequent condition, whereas many children with speech output problems show dyspraxic symptoms at some stage in their developmental history. In a cognitive-neuropsychological approach a comprehensive analysis of psycholinguistic and non-verbal information processing abilities is required to fully specify the speech condition. This paper gives a review of the literature and own research, with emphasis on processing models.

Visuomotor Tracking and Apraxia: A Disorder of Motor Planning

Don Robin, Ph.D.
San Diego State University

Tracking predictable targets requires the development of a motor plan in order to maintain smooth transitions. By contrast, tracking unpredictable targets cannot demand the use of a plan. This session will review the paradigm and our hypotheses in regard to (1) the ability of the tracking paradigm to provide data on the underlying mechanism of apraxia and (2) discuss the paradigms utility as a diagnostic marker for apraxia.

Clinical Classification of Children with Developmental Speech Disorders: A Transdisciplinary Perspective

Megan. M. Hodge, Ph.D.
University of Alberta

Classification systems used for developmental speech disorders and those used by other clinical disciplines for developmental motor disorders (Developmental Coordination Disorder) will be compared with respect to conceptual and methodical issues. Implications of this comparison for linking classification terms to clinical decision making for children with suspected apraxia of speech will be presented.

Translating Research into Clinical Action

Rebecca McCauley, Ph.D.
University of Vermont

Several theoretical and practical approaches for increasing the influence of research on clinical practice will be explored. Two such approaches include (1) incorporating research aims focusing on psychological processes affecting children with CAS as well as other severe speech disorders and (2) anticipating constraints that encourage clinicians to ignore research.

One Thing or Another? Evaluating Category Distinctions

Chris Dollaghan, Ph.D.
University of Pittsburgh

The existence of a category is often treated as a matter for debate rather than as something to be tested empirically. Childhood Apraxia of Speech (CAS) is one of many pediatric behavioral disorders that have been assumed to identify a discrete class of children. This talk concerns a formal method for evaluating rather than assuming the existence of proposed categories such as CAS.

The View from the National Institute on Deafness and Other Communication Disorders

Lana Shekim, Ph.D.
NIH/National Institutes on Deafness and Other Communication Disorders

This presentation will summarize research that is currently funded by the NIDCD. Research within the Voice, Speech and Language portfolios will be highlighted. Based on the research questions generated at the Symposium, a review of the funding mechanisms that are most appropriate for new studies on apraxia of speech in children will be provided.


Lisa Goffman, Ph.D.
Jordan Green, Ph.D.


Thomas Campbell, Ph.D.
Larry Shriberg, Ph.D.

To access the 2002 CAS Symposium Chapters online visit The Hendrix Foundation.