Fig. 2: Learning phase performance varies by dopamine synthesis capacity and set size.

Accuracy as a function of set size, individual differences (median split, n = 46 in each group) in dopamine synthesis capacity in the dorsal caudate nucleus (dCaudate DA), and A the number of previous iterations for each stimulus or B the number of previous correct iterations for each stimulus. Accuracy increases with more iterations of each stimulus on all drugs, and it is higher for those with higher dopamine synthesis capacity. Error bars indicate ± SEM.