Figure 1.

Behavior and overview of NAc neural activity. A, PCA index for each subject calculated as an average over the last 3 d of training. Arrowhead, population mean. B, Average PCA index over 7 d of training for sign trackers (blue) and goal trackers (magenta). Error bars, SEM. C–F, Average normalized activity of neurons with an excitatory cue response (C, D; n = 79) or an inhibitory cue response (E, F; n = 49) around the time of cue onset (C, E) or reward delivery (D, F) on the last day of training. Activity is calculated in 10-ms bins with no smoothing.