Individual Differences in Dopaminergic Modulation of Exploration-Exploitation Behaviour
Journal:
bioRxiv
Published Date:
Jan 31, 2026
Abstract
Dopamine (DA) has been implicated in exploration-exploitation behaviour, i.e., exploring novel, potentiallybetter options vs. exploiting known, previously rewarding options. Impairments in this trade-off occur inpsychiatric disorders involving DAergic dysfunction, including addiction and schizophrenia. Pharmacologicalstudies revealed a contribution of DA to exploration, but inconsistent findings suggest that interindividualvariability in baseline DA may modulate effects. To address this, we investigated the effects of the DAprecursor L-DOPA on exploration-exploitation during reinforcement learning in a sample of N = 75 healthyparticipants (n = 32 women), following a randomised, double-blind, placebo-controlled, pre-registered design(https://osf.io/p2r7u). We assessed whether putative baseline DA markers, including spontaneouseye blink rate, working memory (WM) capacity, and impulsivity, modulated drug effects and probed visualfixation patterns and pupil dilation as markers of exploration. L-DOPA had no overall effect on computationalmodel parameters of random exploration, directed exploration or choice perseveration. WM capacitymoderated drug effects on random exploration, with stronger effects at higher WM capacity. Remaining DAproxies showed no credible effects. Pooling the data from male participants with that from an earlier male-only study (Chakroun et al., 2020; total N = 74), L-DOPA increased uncertainty-dependent value weightingand perseveration strength, while decreasing habit updating, indicating a stronger tendency to repeatprevious choices and slower decay of their influence over time. No credible drug effects were observed infemale participants. Pupil dilation was tonically increased under L-DOPA and scaled with explorationbehaviour and prediction error, confirming that pupillometry can index exploration-exploitation dynamics.Visual exploration patterns reflected uncertainty-driven sampling, but were unaffected by L-DOPA. Takentogether, results suggest that DAergic modulation of exploration and perseveration behaviour may becontingent on cognitive capacity and sex, rather than exerting uniform effects across individuals.
