Gamma abnormalities in autism spectrum disorders

With the current emphasis on atypical patterns of connectivity in the brain hypothesized to be a core feature of autism spectrum disorders (ASDs), there has been a considerable focus over the last decade or so on high-frequency (gamma) band activity (GBA) in both the human and the non-human brain as a measure of connectivity. This chapter provides an overview of the measurement, analysis, and interpretation of GBA and links this to existing neurocognitive and neurophysiological models of ASD. A review of GBA research in ASD, particularly focussing on visual and auditory atypicalities, reveals some consistencies and some inconsistencies, generally arising from the application of different methodologies. It is concluded that, in parallel with emerging theoretical and analytical improvements, the study of GBA and GBA-related processes will continue to offer significant insights into ASD atypicalities at every level, additionally offering the possibility of identifying diagnostic biomarkers, serving as indices of therapeutic progress or contributing to the identification of endophenotypes.