Fig. 1.

Trial sequence, stimuli, and lesions. (A) On each trial, monkeys had to hold their gaze within 3.0° (visual angle) of the red fixation spot for 4 s to receive three small drops of water. On 50% of trials, conditioned stimuli, either CS+ or CS−, were presented for 1 s (CS period) during either the 4-s fixation period or the ITI. If the CS+ was presented, a large drop of water was delivered 0.5 s after the offset of the stimulus (trace period). (B) Intended extent of the subgenual ACC lesion (shaded region) shown on a medial view of a macaque brain (Left) and coronal sections through the frontal lobe (Center). Nissl-stained sections from corresponding levels show the location and extent of the subgenual ACC lesions in cases 1–3 (Right). Colors represent the degree of overlap of the lesions, as indicated in the legend. Numerals indicate the distance in millimeters from the interaural plane.