Biomedical subjects

S Ozonoff

Publications and source records attributed to S Ozonoff.

25 records · Page 2Linked to original sources

PubMed1993

Can standard measures identify subclinical markers of autism?

This study compared the executive function and theory-of-mind abilities of siblings of autistic individuals to those of siblings of learning-disabled controls. Three different analyses of the dependent measures provided convergent support for a potential subclinical marker in the executive function domain. No group differences in theory-of-mind abilities were found. However, power analyses revealed that the measures employed in this study, which are typically used with autistic individuals, were not sufficiently sensitive to detect any group differences that might exist in "unaffected" family members. Suggestions for future research are provided, including the need to develop more sensitive tasks that produce larger effects and measure more elementary cognitive operations.

Adolescent↗

PubMed1993

Developmental aspects of attachment behavior in young children with pervasive developmental disorders.

OBJECTIVE: The present study applied a continuous, clinically based rating system to compare predictions about attachment behavior in autism resulting from three different theoretical views and to characterize differences in attachment behavior of young autistic children. METHOD: The attachment behaviors of 32 young children with autism or pervasive developmental disorder were examined in a modified "strange situation." Attachment behaviors were rated on a continuous scale and on the Ainsworth subscales. Attachment ratings were compared with several developmental variables, including chronological age, mental age, language level, and social level. RESULTS: The continuous rating scale distinguished signs of security from signs of insecurity, allowing for behavioral idiosyncracies in the expression of attachment behavior seen in autistic children. The study found that 50% of the children demonstrated some behaviors indicative of secure attachment, that no children were unattached, and that developmental level rather than severity of autism was the strongest predictor of attachment security. CONCLUSIONS: Autism does not preclude the development of secure attachment relationships in young children, but rather it delays the development of secure attachment and may alter the behavioral patterns that express attachment security.

Autistic Disorder↗

PubMed1991

A comparative study of attachment behavior in young children with autism or other psychiatric disorders.

The present study examined attachment behavior in children with autism and children with other developmental or psychiatric disorders. The groups were matched on chronological and mental age, IQ, and socioeconomic status. When a modified Strange Situation paradigm was used, no group differences were found in proximity seeking, contact maintenance, proximity avoidance, or contact resistance; the groups also did not differ in their overall security ratings. Attachment security was related to several developmental variables in the autistic group but not in the nonautistic comparison group. This suggests that attachment formation may involve different processes in autistic children than in nonautistic children of equivalent intellectual level.

Autistic Disorder↗

PubMed1991

Executive function deficits in high-functioning autistic individuals: relationship to theory of mind.

A group of high-functioning autistic individuals was compared to a clinical control group matched on VIQ, age, sex and SES. Significant group differences were found on executive function, theory of mind, emotion perception and verbal memory tests, but not on spatial or other control measures. Second-order theory of mind and executive function deficits were widespread among the autistic group, while first-order theory of mind deficits were found in only a subset of the sample. The relationship of executive function and theory of mind deficits to each other, and their primacy to autism, are discussed.

Adolescent↗

PubMed1991

Asperger's syndrome: evidence of an empirical distinction from high-functioning autism.

This study compared the neuropsychological profiles of individuals with high-functioning autism (HFA) and Asperger's syndrome (AS). In comparison with matched controls, both groups were impaired on executive function tests. Only the HFA group demonstrated deficits in theory of mind and verbal memory, performing more poorly than both controls and AS subjects. These results suggest that: (1) HFA and AS are empirically distinguishable on measures independent of diagnostic criteria, and (2) impairment on theory of mind measures is not universally found among individuals with autistic spectrum conditions. The primacy of executive function and theory of mind deficits to autism is discussed.

Autistic Disorder↗

PubMed1990

Are there emotion perception deficits in young autistic children?

Two studies were conducted to test the hypothesis that young autistic children are selectively impaired on emotion perception tasks. Results supporting the hypothesis were found on two of the four measures when the controls used were matched on non-verbal mental age; performance on the other tasks was consistent with global deficits across affective and non-affective domains, rather than specific deficits in emotion perception. When the autistic group was compared with controls matched on verbal mental age, no group differences were found. These results suggest that emotion perception impairment is not likely to be the primary underlying deficit in autism. Additional areas for further investigation were suggested.

Analysis of Variance↗

PubMed1990

Neuropsychology of early-treated phenylketonuria: specific executive function deficits.

This study explored the hypothesis that children with early-treated phenylketonuria (PKU) are selectively impaired on executive function measures, even when still on diet. The rationale for this hypothesis is that even mild elevations in phenylalanine (Phe) can lead to lower central levels of biogenic amines, including dopamine (DA). We hypothesize that this mild DA depletion causes subtle prefrontal dysfunction, which in turn affects executive functions such as set maintenance, planning, and organized search. 11 preschool early-treated PKU children (M age = 4.64) and a sample of age- and IQ-matched unaffected peers (n = 11) were evaluated on a battery of executive function (EF) measures. In addition, a "non-executive function" task, recognition memory, was administered to all subjects. Group comparisons demonstrated that PKU children were significantly impaired on an executive function composite score; there were no group differences, however, in recognition memory. These results supported the hypothesized specific deficit in executive function. Furthermore, within the PKU group the executive function composite score was significantly negatively correlated with concurrent phenylalanine levels, even after controlling for the correlation between IQ and executive function skills. This second finding provides support for the proposed biochemical mechanism underlying the specific cognitive deficits.

Child, Preschool↗