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Abstract:
Background. Autism is a neuropsychiatric disorder that is
marked by abnormalities in three major domains of functioning:
social interactions, reciprocal and nonverbal communication, and
restricted repetitive and stereotyped patterns of behavior,
interests, and activities (APA, 1994). Methods. We used ocular
motor paradigms to test hypotheses about frontal lobe$AFbasal
ganglia and parietal lobe dysfunction in autism. We recorded eye
movements in adolescents with high-functioning autism (HFA, n = 11)
and control subjects (n = 17) between the ages of 12 and 18 years,
on predictive saccade, antisaccade, memory-guided saccade and
gap/overlap tasks. Results. Compared to controls, HFAs made a
significantly higher percentage of directional errors on an
antisaccade task (60.9% versus 30.1%, p < .001) and a higher
percentage of response suppression errors on a memory-guided
saccade task (59.1% versus 28.9%, p < .001). HFAs showed a
significantly lower percentage of predictive movements on a
predictive saccade task (p < .01). In contrast, on a gap/overlap
task in which the relative timing of extinction of the fixation
target and appearance of the peripheral target was varied, there
were no significant differences between the two groups in saccade
latency. Conclusions. Adolescents with HFA showed abnormalities of
prediction and suppression in saccade eye movement paradigms but
were able to disengage fixaton normally on a gap/overlap task.
These findings provide support for frontal-basal ganglia
abnormalities but not for parietal dysfunction in autism.
Supported by the National Alliance for Autism Research and the
NIH (MH 52432 R29; HD 35468 P01).
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