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Biomedical subjects

Ami Klin

Publications and source records attributed to Ami Klin.

At least 19 recordsLinked to original sources
PubMed2005

Perception and production of prosody by speakers with autism spectrum disorders.

Speakers with autism spectrum disorders (ASD) show difficulties in suprasegmental aspects of speech production, or prosody, those aspects of speech that accompany words and sentences and create what is commonly called "tone of voice." However, little is known about the perception of prosody, or about the specific aspects of prosodic production that result in the perception of "oddness." The present study examined the perception and production of a range of specific prosodic elements in an experimental protocol involving natural speech among speakers with ASD between 14 and 21 years of age, in comparison with a typical control group. Results revealed ceiling effects limiting interpretation of findings for some aspects of prosody. However, there were significant between-group differences in aspects of stress perception and production. The implications of these findings for understanding prosodic deficits is speakers with autism spectrum disorders, and for future research in this area, are discussed.

Adolescent↗
PubMed2005

Three diagnostic approaches to Asperger syndrome: implications for research.

OBJECTIVE: To examine the implications for research of the use of three alternative definitions for Asperger syndrome (AS). Differences across the three nosologic systems were examined in terms of diagnostic assignment, IQ profiles, comorbid symptoms, and familial aggregation of social and other psychiatric symptoms. METHOD: Standard data on diagnosis, intellectual functioning, comorbidity patterns, and family history were obtained on 65 individuals screened for a very high probability of having autism without mental retardation (or higher functioning autism, HFA) or AS. Diagnoses of AS were established based on three different approaches: DSM-IV, presence/absence of communicative phrase speech by 3 years, and a system designed to highlight prototypical features of AS. RESULTS: Agreement between the three diagnostic systems was poor. AS could be differentiated from HFA (but not from PDD-NOS) on the basis of IQ profiles in two of the three systems. Differences in patterns of comorbid symptomatology were obtained in two of the three systems, although differences were primarily driven by the PDD-NOS category. Only one of the approaches yielded differences relative to aggregation of the "broader phenotype" in family members. CONCLUSIONS: Diagnostic assignments of AS based on three commonly used approaches have low agreement and lead to different results in comparisons of IQ profiles, patterns of comorbidity, and familial aggregation of psychiatric symptoms across the approach-specific resultant groups of HFA, AS, and PDD-NOS.

Adolescent↗
PubMed2005

Asperger's syndrome: a comparison of clinical diagnoses and those made according to the ICD-10 and DSM-IV.

The diagnostic criteria for Asperger Syndrome (AS) according to ICD-10 and DSM-IV have been criticized as being too narrow in view of the rules of onset and precedence, whereby autism takes precedence over AS in a diagnostic hierarchy. In order to investigate this further, cases from the DSM-IV multicenter study who had been diagnosed clinically with AS were assigned to appropriate DSM-IV/ICD-10 diagnostic categories. The analysis indicated that 11(23%) cases would be reassigned a diagnosis of autism by either ICD-10 or DSM-IV according to their onset and precedence rules, and 33(68%) would be diagnosed with AS. These results contrast with those of others who have stated that the diagnosis of AS using ICD-10/DSM-IV criteria is 'virtually impossible'. It is suggested that this is due to limitations inherent in these criteria, and alternative conceptualizations are discussed.

Asperger Syndrome↗
PubMed2005

Autism in infancy and early childhood.

Although initially described as an inborn disorder of affective contact, information on autism as it exists in infants has been limited. Delays in diagnosis, lack of information about the condition, and reliance on retrospective research strategies have been problematic. An awareness of the increased risk for siblings is now allowing the development of new, prospective approaches. Consistent with Kanner's original hypothesis, the available information strongly suggests a fundamental difficulty in the earliest social processes, which, in turn, impacts many other areas of development. New approaches to screening have lowered the age of initial diagnosis; this presents new challenges for early intervention. Directions for future research are highlighted.

Autistic Disorder↗
PubMed2005

Source memory in children with autism spectrum disorders.

The evidence to date regarding memory processes in children with autism spectrum disorders (ASD) remains equivocal. Although children with these neurodevelopmental disorders have been shown to display exceptional memories for fact-based information, they seem to be less able to attach meaning or context to their memories. Thus, this study investigated the specific role of source memory in autism. Children with ASD were compared to a chronological and mental age-matched comparison group of typically developing children. Although children with autism performed similarly to controls on a fact recognition measure, their performance on a source memory task was significantly lower. The findings indicated, however, that the nature of source memory confusion in children with autism does not appear to reflect a generalized deficit in attaching context to memories but rather is dependent on the specific to-be-remembered information that, in this study, involves social aspects of context.

Adolescent↗
PubMed2004

Disruption of contactin 4 (CNTN4) results in developmental delay and other features of 3p deletion syndrome.

3p deletion syndrome is a rare contiguous-gene disorder involving the loss of the telomeric portion of the short arm of chromosome 3 and characterized by developmental delay, growth retardation, and dysmorphic features. All reported cases have involved, at a minimum, the deletion of chromosome 3 telomeric to the band 3p25.3. Despite the presence of several genes in this region that are involved in neural development, a causative relationship between a particular transcript and the observed clinical manifestations has remained elusive. We have identified a child with characteristic physical features of 3p deletion syndrome and both verbal and nonverbal developmental delay who carries a de novo balanced translocation involving chromosomes 3 and 10. Fine mapping of this rearrangement demonstrates that the translocation breakpoint on chromosome 3 falls within the recently identified minimal candidate region for 3p deletion syndrome and disrupts the Contactin 4 (CNTN4) mRNA transcript at 3p26.2-3p26.3. This transcript (also known as BIG-2) is a member of the immunoglobulin super family of neuronal cell adhesion molecules involved in axon growth, guidance, and fasciculation in the central nervous system (CNS). Our results demonstrate the association of CNTN4 disruption with the 3p deletion syndrome phenotype and strongly suggest a causal relationship. These findings point to an important role for CNTN4 in normal and abnormal CNS development.

Cell Adhesion Molecules, Neuronal↗
PubMed2004

Deficits in social attribution ability in Prader-Willi syndrome.

Prader-Willi syndrome (PWS), a genetic form of mental retardation, involves a myriad of physical and behavioral problems. Poor social adjustment has been reported, but the origin of this difficulty is unknown. The Social Attribution Task, a measure of one's ability to make appropriate social attributions from an ambiguous visual display [Klin (2000) Journal of Child Psychology and Psychiatry, 33(5) [861-876] was administered to study participants with PWS, participants with pervasive developmental disorder and an IQ matched comparison group with no known syndrome. The participants with PWS performed significantly more poorly than participants with comparable intellectual ability, and not significantly differently from the group of participants with a pervasive developmental disorder. Poor performance on this task by the PWS participants suggests an underlying difficulty interpreting social information that is presented visually, which may be a critical factor in the impairment in social functioning in this population.

Analysis of Variance↗
PubMed2004

Performance on Cambridge Neuropsychological Test Automated Battery subtests sensitive to frontal lobe function in people with autistic disorder: evidence from the Collaborative Programs of Excellence in Autism network.

Recent structural and functional imaging work, as well as neuropathology and neuropsychology studies, provide strong empirical support for the involvement of frontal cortex in autism. The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a computer-administered set of neuropsychological tests developed to examine specific components of cognition. Previous studies document the role of frontal cortex in performance of two CANTAB subtests: the Stockings of Cambridge, a planning task, and the Intradimensional/Extradimensional Shift task, a measure of cognitive set shifting. To examine the integrity of frontal functions, these subtests were administered to 79 participants with autism and 70 typical controls recruited from seven universities who are part of the Collaborative Programs of Excellence in Autism network. The two groups were matched on age, sex, and full-scale IQ. Significant group differences were found in performance on both subtests, with the autism group showing deficits in planning efficiency and extradimensional shifting relative to controls. Deficits were found in both lower- and higher-IQ individuals with autism across the age range of 6 to 47 years. Impairment on the CANTAB executive function subtests did not predict autism severity or specific autism symptoms (as measured by the ADI-R and ADOS), but it was correlated with adaptive behavior. If these CANTAB subtests do indeed measure prefrontal function, as suggested by previous research with animals and lesion patients, this adds to the accumulating evidence of frontal involvement in autism and indicates that this brain region should remain an active area of investigation.

Adolescent↗
PubMed2004

Adaptive behavior in autism and Pervasive Developmental Disorder-Not Otherwise Specified: microanalysis of scores on the Vineland Adaptive Behavior Scales.

The purpose of this study is to provide a microanalysis of differences in adaptive functioning seen between well-matched groups of school-aged children with autism and those diagnosed as having Pervasive Developmental Disorder-Not Otherwise Specified, all of whom functioned in the mild to moderate range of intellectual impairment. Findings indicate that the major area of difference between children with autism and those with Pervasive Developmental Disorder-Not Otherwise Specified, was expressive communication; specifically, the use of elaborations in syntax and morphology and in pragmatic use of language to convey and to seek information in discourse. Linear discriminant function analysis revealed that scores on just three of these expressive communication item sets correctly identified subjects in the two diagnostic categories with 80% overall accuracy. Implications of these findings for both diagnosis and intervention with children with Autism Spectrum Disorders will be discussed.

Activities of Daily Living↗
PubMed2004

Autism and pervasive developmental disorders.

The quantity and quality of research into autism and related conditions have increased dramatically in recent years. Consequently we selectively review key accomplishments and highlight directions for future research. More consistent approaches to diagnosis and more rigorous assessment methods have significantly advanced research, although the boundaries of the 'broader phenotype' remain to be defined and the validity of Asperger's disorder as a discrete syndrome remains controversial. Recent epidemiological studies have shown that Autism Spectrum Disorders are common, but there continues to be debate about the causes of the increase in the frequency with which autism is diagnosed. Psychological research has helped to develop new developmental models for the disorder and there have also been significant advances in the molecular genetics of autism and understanding of the underlying neurobiological processes. Areas important for future research include the study of autism as it first develops, i.e., in infants and very young children, and of specific processes (psychological and neurobiological) which underlie the disorder. Significant challenges lie ahead in evaluating the growing number of treatments for autism and in integrating the results of research into treatment and educational settings.

Autistic Disorder↗
PubMed2003

The enactive mind, or from actions to cognition: lessons from autism.

Normative-IQ individuals with autism are capable of solving explicit social cognitive problems at a level that is not matched by their ability to meet the demands of everyday social situations. The magnitude of this discrepancy is now being documented through newer techniques such as eye tracking, which allows us to see and measure how individuals with autism search for meaning when presented with naturalistic social scenes. This paper offers an approach to social cognitive development intended to address the above discrepancy, which is considered a key element for any understanding of the pathophysiology of autism. This approach, called the enactive mind (EM), originates from the emerging work on 'embodied cognitive science', a neuroscience framework that views cognition as bodily experiences accrued as a result of an organism's adaptive actions upon salient aspects of the surrounding environment. The EM approach offers a developmental hypothesis of autism in which the process of acquisition of embodied social cognition is derailed early on, as a result of reduced salience of social stimuli and concomitant enactment of socially irrelevant aspects of the environment.

Autistic Disorder↗
PubMed2003

The role of the fusiform face area in social cognition: implications for the pathobiology of autism.

A region in the lateral aspect of the fusiform gyrus (FG) is more engaged by human faces than any other category of image. It has come to be known as the 'fusiform face area' (FFA). The origin and extent of this specialization is currently a topic of great interest and debate. This is of special relevance to autism, because recent studies have shown that the FFA is hypoactive to faces in this disorder. In two linked functional magnetic resonance imaging (fMRI) studies of healthy young adults, we show here that the FFA is engaged by a social attribution task (SAT) involving perception of human-like interactions among three simple geometric shapes. The amygdala, temporal pole, medial prefrontal cortex, inferolateral frontal cortex and superior temporal sulci were also significantly engaged. Activation of the FFA to a task without faces challenges the received view that the FFA is restricted in its activities to the perception of faces. We speculate that abstract semantic information associated with faces is encoded in the FG region and retrieved for social computations. From this perspective, the literature on hypoactivation of the FFA in autism may be interpreted as a reflection of a core social cognitive mechanism underlying the disorder.

Adult↗
PubMed2003

Reduced thalamic volume in high-functioning individuals with autism.

BACKGROUND: In this study, specific consideration is given to a role for the thalamus in autism. METHODS: A volumetric analysis of the thalamus was conducted using magnetic resonance imaging, based on segmentation of continuous 1.2 mm(3) coronal images. The sample consisted of 12 high-functioning individuals with autism, mean age of 21.0 years (SD = 10.4) and mean IQ of 106.4 (SD = 18.3). Normal control subjects were selected to match this group; the mean age was 18.1 years (SD = 6.3); mean IQ was 108.8 (SD = 15.6). RESULTS: Unadjusted mean thalamic volume was not significantly different; however, there were significant differences in the relationship between thalamic volume and total brain volume (TBV). The correlation was strong and positive in the control group but statistically nonsignificant in the autism group. Group differences were found when adjustments were made for TBV, achieved by grouping subjects' measurements on this variable using a split median procedure. Mean thalamic volume was significantly reduced in the autism group relative to normal control subjects, specifically within the high TBV group. CONCLUSION: The increase in thalamic volume with increase in TBV was not seen in autism, suggesting underdeveloped connections between cortical and subcortical regions and indicating a need to examine this structure further.

Adolescent↗
PubMed2003

Asperger syndrome: diagnosis and external validity.

This article provides an overview of the history and clinical features of Asperger syndrome and considers guidelines for clinical assessment and treatment. A review of issues related to external validity is provided that points out the limitations of current research and lists several potentially beneficial areas of investigation into the nosologic status of the condition. It concludes with a discussion of the unequivocal need of individuals with severe social disabilities for comprehensive and adequate educational services and other treatments, regardless of the fact that the validity and usefulness of this specific diagnostic concept is far from resolved.

Adolescent↗