(a) The microinjectrode was placed in the right hemisphere, FEF area. (b) Behavioral performance during an MGS task in which eight targets are placed peripherally. We ran 4 blocks of the MGS task, before and at three times after injection. Polar plot shows performance (eccentricity) at each of these times (color), for different locations relative to the fixation point (angle on polar plot). Performance clearly decreased in the left visual hemifield 2 h after injection (blue trace, left half of polar plot). (c) Saccade traces for 8 peripheral memory locations before (left) and after muscimol injection in the FEF (right, 1 and 3 h post-infusion). Saccade accuracy in the left visual hemifield (left half of polar plots) decreased after muscimol injection. Scale in degrees of visual angle (dva).