Fig. 3.

Mean cumulative errors made over the first session of the reversal (EDSR) by monkeys that received excitotoxic lesions of either the lateral (LAT) (n = 3) (filled triangles) or orbital prefrontal cortex (ORB) (n = 3) (filled circles) or a sham operation (n = 3) (open circles). Horizontal line ata and b indicates the level of performance significantly different from chance (p < 0.05) on 16 trials, i.e., 12 or more incorrect responses, and 20 trials, i.e., 15 or more incorrect responses, respectively.