Grand mean total gamma band activity. (a) Mean percent change from baseline in tGBA for each individual condition. Left column shows activity on object trials, right column shows activity on non-object trials. (b) topography of tGBA averaged across all conditions, 40–90 Hz, and 200-500 ms. Black ovals indicate the electrode clusters used for analysis. (c) Bar graph showing mean percent change in tGBA for each condition. Red bars show tGBA on object trials, blue on non-object trials. Error bars depict 95% confidence intervals.