Fig. 2.

Sensorimotor and associative memory tasks. In theSensory Motor condition, memory was not required either because the reward was in sight at the response phase (Fig. 2) or because all stimuli were baited (data not shown). An intertrial interval separated each trial, and there was no relationship between trials. In the Visual Pattern Discrimination condition, the monkey had to learn an association between a stimulus (the + sign card) and the reward. This association did not vary from trial to trial and from day to day. The + sign indicates that a reward is hidden behind the plaques or objects (reinforced stimulus), whereas the − sign signifies the absence of positive reinforcement;arrows indicate the correct response.