While ACCs-lesioned monkeys did render animals worse at performing the task, they were in fact no more slow to switch between responses than control animals. Inspection of Figure 6b shows that the ACCs-group were just as poor at choosing the rewarded action in the ten trials running up to an imposed switch, when they have experienced more than 15 rewards for selecting the correct action, as on the ten trials afterwards. Interestingly, in spite of many months training on this task during which the failure to receive an expected reward always indicated that the other response was correct, control animals changed their response choice on the first trial after a switch on only approximately 60% of trials (E+1 trial, far left of Figure 7a). This suggests that errors and rewards do not naturally operate like the explicit sensory cues that instruct actions in a conditional learning paradigm; instead, to a foraging animal, a single negative outcome is a piece of evidence that the chosen response may no longer be the best course of action, a fact that is weighed against
