Extended Data Fig. 1: Dopamine neurons and recording sites.

a, Example dopamine waveform from one of the neurons in our population. b, The population of 40 neurons used for our analyses in the Pavlovian and choice task had significant activations following unpredicted rewards – a characteristic feature of dopamine neurons. Gray bar along the x axis indicate the response window used for analysis. c, Recording locations for the left hemisphere of monkey S. X axis indicates lateral to medial location in the grid in millimeters, relative to midline (0). Right y axis indicates posterior to anterior location in the grid in millimeters, relative to interaural line (IAL). Each locations’ color indicates the number of neurons recorded for that location. Black circles surrounding the individual locations indicated that neurons recorded there were part of the population of 29 neurons that had a steeper response slopes in normal compared to uniform condition. Bar graphs on the left and top axes indicate the proportion of cells in that AP (left) or ML (top) location that were effect positive. Yellow dot corresponds to location indicated in MRI scan shown in d and e. d, Recording locations for the left hemisphere of monkey B. Same as panel c. e, Sagittal view MRI of the recording chamber of monkey S. Purple arrow indicates the AP location in the grid (+12 mm from IAL). f, Coronal view MRI of the recording chamber of monkey S. Purple arrow indicates the ML location in the grid (1 mm from Midline). Yellow dot in e and f correspond to approximate recording grid location in c.