Figure 2.

Activity of one neuron. a. Rasters. Each line represents one trial and each small dot represents one spike. Trials, arranged by offer type, are aligned at the offer (left) and at the juice (right). The blue highlight marks the post-juice time window. b. Activity profiles shown separately for trials in which juice A is offered on the left (red) or on the right (green). The cell activity does not depend on the spatial configuration of the visual stimulus. c. Activity profiles shown separately for trials in which the monkey chooses the juice offered on the left (red) or on the right (green). The cell activity does not depend on the direction of the eye movement. d. Top: choice pattern recorded in this session (n*=1.9). Bottom: activity of the cell (±s.e.m.) recorded in the pre-offer (light gray, control) and post-juice time window (black). Note that the response does not reflect simple physical properties of the visual stimulus, such as the number of squares displayed on the monitor. For example, offer types 1B:3A and 3B:1A, which are visually identical except for the color of the squares, elicit very different activation.