Fig. 2: Proportion of ‘stay’ choices of the Sequential Model-Based/Model Free Task.

A The proportion of first-stage stay choices is shown as a function of outcome of the previous trial for each group, separately for trials following common and rare transitions. The figure shows that both the placebo and escitalopram groups responded in a model-based way. B The proportion of first-stage stay choices is graphed as a function of outcome of the previous trial for each group averaged across transition type. The figure shows that the escitalopram group were less likely to stay following a reward compared to the placebo group. This result suggests lower reinforcement sensitivity in the escitalopram group. The error bars represent ±1 SEM.