Dopamine manipulations drive changes in information sampling in healthy volunteers

Background: Information sampling is the cognitive process of accumulating information before committing to a decision. Patients across numerous disorders show decreased information sampling relative to controls. Aims: Here, we used the Beads and the Best Choice Tasks to study the role of dopamine signaling in information sampling. Methods: Participants were given placebo, amisulpride, or ropinirole in each session, in a double-blind cross-over design. Results: We found that ropinirole (agonist) increased the number of beads drawn in the Beads Task specifically when participants faced a loss, and decreased the rank of the chosen option in the Best Choice Task. Conclusions: These effects are likely driven by a combination of effects at presynaptic D2 receptors, which affect dopamine release, and post-synaptic D2 receptors. Increased D2 relative to D1 receptor activation in the striatum leads to increased sampling in the loss condition in the Beads Task. It also leads to choice of a poorer ranked option in the Best Choice Task. Decreased D2 relative to D1 receptor activation leads to decreased sampling in the Beads Task in the loss condition.