Figure 2.

An example of directional delay-period activity observed in the prefrontal cortex. The visual cue was presented randomly at one of predetermined 8 peripheral positions. The position of each figure corresponds to the position of the visual cue. Significant activation was observed during the delay period only when the visual cue was presented at the 270° position. C: cue period (0.5 s). D: delay period (3.0 s). R: response period. Reproduced from Funahashi et al. (1989).