Figure 3.

Activity of a representative LC unit. Raster display for the activity of a representative LC neuron aligned on the cue onset in cued trials (A) and the feedback in cued (B) and self-initiated (C) trials. In A and C, trials are sorted by decreasing reward sizes, with the three levels of blue corresponding to the three levels of reward. Trials corresponding to different conditions are separated by broken lines. For this neuron, expected reward modulates (positively) the firing at the cue (A) but not at the action in self-initiated trials (C). At the feedback in cued trials (B), trials are sorted by trial type (black, active trials; gray, passive trials). The activation before the feedback only occurs in active trials, when monkeys need to perform an operant action (bar release) to get the reward. In passive trials, there is a small activation after the visual feedback.