Figure 1.

a, Spatial WM task with a retro cue. The initial memory set consisted of two, four, or six dots presented in different locations on each trial, followed by delay 1 (the study phase). An orange or blue updating cue then indicated the one ([1/1] and [1/3] conditions) or three ([3/1] and [3/3]) dot locations of the original memory set that remained relevant throughout delay 2 (the cue phase). Finally, a probe appeared prompting a recognition response. b, Behavioral results indicating accuracy and RT differences between the four experimental conditions. c, Alpha power activity for the full trial of all four conditions. Gray shaded regions indicate the study and cue displays. Top right inset, Montage of scalp electrodes. Starred electrodes are significant at the p < 0.05 level over the delay 2 period (500–2000 ms postcue onset; see Materials and Methods).