Functional brain organization for visual search in ASD.

摘要: Although previous studies have shown that individuals with autism spectrum disorder (ASD) excel at visual search, underlying neural mechanisms remain unknown. This study investigated the neurofunctional correlates of search in children ASD and matched typically developing (TD) children, using an event-related functional magnetic resonance imaging design. We used a paradigm, manipulating difficulty by varying set size (6, 12, or 24 items), distractor composition (heterogeneous homogeneous) target presence to identify brain regions associated efficient inefficient search. While group did not evidence accelerated response time (RT) compared TD group, they demonstrate increased efficiency, as measured RT slopes. Activation patterns also showed differences between which recruited network including frontal, parietal, occipital cortices, less extensive activation mostly limited occipito-temporal regions. Direct comparisons (for both homogeneous heterogeneous conditions) revealed greater frontoparietal than participants. These results suggest efficiency may be related enhanced discrimination (reflected activation) top-down modulation attention (associated activation). (JINS, 2008, 14, 990–1003.)