Disordered visual processing and oscillatory brain activity in autism and Williams Syndrome

Two developmental disorders, autism and Williams syndrome, are both commonl y described as having difficulties in integrating perceptual features, i.e. binding spatially separate elements into a whole. It is already known that healthy adults and infants display electroencephalographic (EEG) gamma -ba nd bursts (around 40 Hz) when the brain is required to achieve such binding . Here we explore gamma -band EEG in autism and Williams Syndrome and demon strate differential abnormalities in the two phenotypes. We show that despi te putative processing similarities at the cognitive level, binding in Will iams syndrome and autism can be dissociated at the neurophysiological level by different abnormalities in underlying brain oscillatory activity. Our s tudy is the first to identify that binding-related gamma EEG can be disorde red in humans. NeuroReport 12:2697-2700 (C) 2001 Lippincott Williams & Wilk ins.