Fig. 1.
Reward-guided task and excitotoxic amygdala lesions. (A) The sequence of events in a single trial of the two-option reward-guided task. Event timing and analysis periods are highlighted as well as dual neurophysiology and ECG recordings. A monkey could initiate a trial by placing its hand on a central button and fixing its gaze on a fixation spot in the center of the monitor. On each trial, monkeys were presented with two stimuli from a given stimulus set. After the fixation spot brightened (“Go” signal), the monkey could choose the left or right stimulus by moving its hand to the left or right button, respectively. After 500 ms, the reward amount assigned to the chosen stimulus was delivered. (B) The two stimulus sets used and corresponding reward amounts. (C) Bilateral excitotoxic lesions of the amygdala in monkeys H, N, and V as assessed by T2-weighted MRI scans taken within 5 d of infusions of excitotoxins (Top) and Nissl-stained sections at matching levels after histological processing (Bottom).