Fig. 1

Visually induced gamma activity in the TD and ASD groups: grand-averaged time–frequency plots of HGO power changes elicited by gratings drifting at velocities of 1.2, 3.6, and 6.0 °/s. TF plots are shown for gradiometer’s pair MEG2112 and MEG2113 located at the scalp topographical maximum of gamma response. Color scale represents power changes in dB relative to pre-stimulus baseline. Vertical line marks the stimulus onset; horizontal lines correspond to the mean velocity-specific peak frequency (VSPF) in the TD group