Fig. 6

Valence of expected reward size encoding. a Firing rates of two example neurons recorded from the same electrode. Both encode expected reward size, but with opposing valence. b Significant encoding of expected reward size over time in HGA. The x axis shows time concatenated across the three epochs, picture onset (first), response (middle), and reward receipt (last), as in Fig. 3. Electrodes with positive (red) and negative (blue) encoding valence were sorted separately and overlaid. c The same plot as (b), but for single neurons. d Mean latencies to encode expected reward size ± 95% CI, separated based on whether the response was higher for larger (positive, red) or smaller rewards (negative, blue). Mean latencies for each subject are also shown: x = subject M, square = subject N