Fig. 1.

Behavioral task and cell groups. A: juice choice task. At the beginning of each trial, the animal fixated on the center of a screen. Two sets of colored squares, representing the two offers, appeared after 0.5 s. For each offer, the color indicated the juice identity, and the no. of squares indicated the juice quantity. The animal maintained center fixation for a randomly variable delay (1–2 s), after which the fixation point disappeared, and two saccade targets appeared by the offers (go cue). The animal indicated its choice with a saccade and maintained peripheral fixation for 0.75 s before juice delivery. B: neuron encoding the offer value A. The x-axis represents different offer types ranked by the ratio #B:#A. Black symbols represent the percent of “B” choices. Red symbols represent the neuronal firing rate (diamonds and circles indicate, respectively, choices of juice A and juice B). To highlight the variability in firing rates, thinner error bars here indicate the SD, and thicker error bars indicate the SE. C: neuron encoding the offer value B. D: neuron encoding the chosen value. E: neuron encoding the chosen juice. All conventions C–E are as in B.