Fig. 1. Task design and results for Pavlovian-to-instrumental transfer (PIT) task.

a In the initial instrumental conditioning phase, participants learned to associate distinct behavioral responses (key presses) with distinct primary reinforcers (popcorn and smarties). b During Pavlovian conditioning, participants associated four different predictive cues with one of four outcome types (popcorn, smarties, cashew nuts, and nothing). c In the final transfer-test PIT phase, we measured key presses to the Pavlovian cues. d In individuals with high baseline WMC, stronger D1R stimulation increased PIT (independently of PIT type), indicating enhanced cue reactivity. No significant drug effects occurred in low WMC individuals.