The visually guided saccade task.

<p>A trial started when a small fixation spot appeared on the screen. After the monkeys maintained fixation on the spot for 1200 ms, the fixation spot disappeared and a peripheral target appeared at either right or left. The monkeys were required to make a saccade to the target within 1000 ms. In one block of 36 trials, saccades to one fixed direction were followed by electrical stimulation of the LHb while saccades to the other direction were not. The direction-stimulation contingency was reversed in the next block.