Fig. 1.

WM tasks and PFC population dynamics. (A) In the ODR task, the subject fixates on a central point, and a visuospatial cue of variable spatial angle is presented for 0.5 s, followed by a 3-s mnemonic delay. After the delay, the subject makes a saccadic eye movement to the remembered location (14). (B) In the VDD task, the subject receives a 0.5-s vibrotactile stimulus of variable mechanical frequency (cue, f1) to the finger, followed by a 3-s mnemonic delay. After the delay, a second stimulus (f2) is presented and the subject reports, by level release, which stimulus had a higher frequency (15). (C and D) Correlation between population states as a function of time, within the same stimulus condition. The sensory state is defined by the first 0.25 s of the cue epoch and the late memory state by the last 0.25 s of the delay epoch. Colored shaded regions mark SEM. (E and F) Correlation between the population states at different timepoints (i.e., time-lagged autocorrelation). The correlation between states is generally high due to a broad distribution of overall firing rates across neurons (Fig. S2). The traces in C and D are slices along the corresponding timepoint.