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Biomedical subjects

Ami Klin

Publications and source records attributed to Ami Klin.

12 recordsLinked to original sources
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↗
PubMed2003

Concurrent validity and classification accuracy of the Leiter and Leiter-R in low-functioning children with autism.

The concurrent validity of the Leiter International Performance Scale (Leiter) and Leiter International Performance Scale-Revised (Leiter-R) was examined in a sample of children with autism who could not be assessed with more traditional measures of intelligence (e.g., the Wechsler scales). The sample consisted of 26 children ranging in age from 4 to 16 years. The correlation between the Leiter scales was high (r = .87), and there was a difference of 3.7 points between the two mean scores, nonsignificant at both statistical and clinical levels. However, significant intraindividual discrepancies were present in 10 cases, 2 of which were both large (24 and 36 points) and clinically meaningful. The mean profile of performance on Leiter-R subtests is also presented for this sample of children with autism, to allow for comparison with other groups. Based on the results of this initial evaluation, together with the current normative data, good psychometric properties, and availability of global and subtest scores with the Leiter-R, the instrument is generally recommended for use with children with autism. However, because of changes in the design of the Leiter-R, there may be greater clinical success with the original Leiter for those children who are very low functioning and severely affected, particularly younger children.

Adolescent↗
PubMed2003

Asperger syndrome: an update.

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, which 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 irrespective of the fact that the validity and the utility of this specific diagnostic concept is far from resolved.

Asperger Syndrome↗
PubMed2002

Visual fixation patterns during viewing of naturalistic social situations as predictors of social competence in individuals with autism.

BACKGROUND: Manifestations of core social deficits in autism are more pronounced in everyday settings than in explicit experimental tasks. To bring experimental measures in line with clinical observation, we report a novel method of quantifying atypical strategies of social monitoring in a setting that simulates the demands of daily experience. Enhanced ecological validity was intended to maximize between-group effect sizes and assess the predictive utility of experimental variables relative to outcome measures of social competence. METHODS: While viewing social scenes, eye-tracking technology measured visual fixations in 15 cognitively able males with autism and 15 age-, sex-, and verbal IQ-matched control subjects. We reliably coded fixations on 4 regions: mouth, eyes, body, and objects. Statistical analyses compared fixation time on regions of interest between groups and correlation of fixation time with outcome measures of social competence (ie, standardized measures of daily social adjustment and degree of autistic social symptoms). RESULTS: Significant between-group differences were obtained for all 4 regions. The best predictor of autism was reduced eye region fixation time. Fixation on mouths and objects was significantly correlated with social functioning: increased focus on mouths predicted improved social adjustment and less autistic social impairment, whereas more time on objects predicted the opposite relationship. CONCLUSIONS: When viewing naturalistic social situations, individuals with autism demonstrate abnormal patterns of social visual pursuit consistent with reduced salience of eyes and increased salience of mouths, bodies, and objects. Fixation times on mouths and objects but not on eyes are strong predictors of degree of social competence.

Adolescent↗
PubMed2002

A descriptive study of hyperlexia in a clinically referred sample of children with developmental delays.

In this study, we evaluated the incidence of hyperlexia in a clinically referred sample of 80 children with developmental delays. Based on hypotheses previously formulated in the literature, the study investigated the frequency of hyperlexia among boys and girls, the incidence of hyperlexia in children with Pervasive Developmental Disorders (PDD)-spectrum compared with non-PDD diagnoses, the range of IQ and of various cognitive skills in children with and without hyperlexia, and the developmental outcomes of children with and without hyperlexia. The results revealed no significant differences in the frequency of hyperlexia in girls compared with boys. However, the frequency of hyperlexia was significantly elevated among children with PDD compared with children with non-PDD diagnoses. The range of IQ and other cognitive skills and the developmental outcomes of children with hyperlexia were comparable to those of children without hyperlexia.

Child↗
PubMed2002

Defining and quantifying the social phenotype in autism.

OBJECTIVE: Genetic and neurofunctional research in autism has highlighted the need for improved characterization of the core social disorder defining the broad spectrum of syndrome manifestations. METHOD: This article reviews the advantages and limitations of current methods for the refinement and quantification of this highly heterogeneous social phenotype. RESULTS: The study of social visual pursuit by use of eye-tracking technology is offered as a paradigm for novel tools incorporating these requirements and as a research effort that builds on the emerging synergy of different branches of social neuroscience. CONCLUSIONS: Advances in the area will require increased consideration of processes underlying experimental results and a closer approximation of experimental methods to the naturalistic demands inherent in real-life social situations.

Adult↗
PubMedDate not supplied

Automatic attention cueing through eye movement in 2-year-old children with autism.

Automatic attention cueing by perceived changes in gaze direction was studied in 2-year-old children with autism and typically developing (TD) controls using a visual attention cueing paradigm. In Experiments 1 and 2 the cue consisted of an eye movement (Eyes) and a nonbiological movement (SimEyes), respectively. The results suggest that visual attention in children with autism and their TD counterparts is cued by perceived eye movement. Thus, although in naturalistic situations toddlers with autism do not follow the gaze of others, they are sensitive to directional cues inherent in eye movement. Cue-specific differences in performance related to the level of engagement and cue-processing time may suggest reliance on different underlying strategies for gaze processing in autism.

Attention↗