Fig. 1.

The free-viewing visual search task. After an initial fixation period (1–1.75 s), the central fixation spot extinguished and the search array appeared without any delay. One of the stimuli, either the target (an upright or inverted T) or a distractor, appeared in the center of the neuron's receptive field (dashed line). Monkeys had 3 s to report the orientation of the target by releasing one of two bars. During the presentation of the search array, no constraints were imposed on the monkey's eye movements and they were not required to fixate the target before giving the response