Figure 2.
Behavioral task and animals’ performance. (A) Sequence of events in the one-direction-rewarded version of the visually guided saccade task (1DR). The monkey first fixated at the central spot (the dotted circle indicates the eye position). As the fixation point disappeared, a target appeared randomly on the right or left and the monkey was required to make a saccade to it immediately. Correct saccades in one direction were followed by a tone and juice reward; saccades in the other direction followed by a tone alone. The rewarded direction was fixed in a block of 24 trials, and was changed in the following block. (B) Distribution of saccade latencies in rewarded trials (in red) and in unrewarded trials (in blue) (data from monkey D). Saccades in the first trials after the changes in position-reward contingency have been excluded.