Figure 3.

Neuronal responses in primate amygdala reflecting reward surprise. Responses decrease with increasing reward prediction (defined by increasing instantaneous reward probability). Dotted line: responses to unpredicted reward delivered without any preceding stimulus. Second line from top (red online): reward responses during a stimulus that predicts the occurrence but not the time of a pseudorandomly occurring reward. Third line from top (blue online): responses to a fully predicted, fixed reward delivered 2 s after stimulus presentation. Bottom line (black online): activity at 2 s following a non-rewarded stimulus. (a) Single neuron. (b) Averaged population responses (n = 15 neurons) (adapted from [55]). (Online version in colour.)