Figure 1.

Experimental design for measuring attentional modulation. A, Sequence of events in one trial. Drifting Gabor patches were briefly presented (200 ms) multiple times in each trial. Each presentation of Gabor patches was followed by blank periods of random duration (94–294 ms). The number of the Gabors and the direction of each Gabor were randomly selected from the predefined set. Attentional location of the animal was directed by a spatial cue (annulus) or instruction trials, and the task was to detect the appearance of a Gabor with a higher drift speed (indicated by a longer arrow) at the cued location. B, Stimulus and attention conditions that were collected and analyzed. A total of 48 conditions (16 stimulus conditions × 3 attention conditions) of responses were collected from each MT neuron.