Deciding how to Decide: Dopaminergic Mechanisms of Meta Decision-Making

Abstract

To successfully navigate life, it is crucial not only to make the right decisions but also to determine how much time and effort you want to invest into the decision process itself. Previously, it has been shown that the average reward available in the environment influences cognitive effort exertion and the neurotransmitter dopamine has been proposed as a neural candidate for encoding this average reward rate. In the present study, we investigated the effects of an average reward rate manipulation on cognitive effort in a novel, self-paced perceptual decision-making task in two independent samples (Nbehavioural = 30, Npharmacology = 46). The role of dopamine in these processes was assessed in a within-subject, double-blind design using the dopamine D2 receptor antagonist sulpiride in the pharmacological sample. In both samples, a high average reward rate led to cognitive effort withdrawal, whereas physical vigour increased with average reward rate in the pharmacology sample. Participants showed different strategies for the task, resulting in large variations in completed trials and possible bonus. In addition, hypothesised results for sulpiride administration are discussed. The findings support the role of the environmental reward rate in the meta-decision of exerting versus withdrawing cognitive effort. Keywords: cognitive effort, average reward rate, response vigour, dopamine, sulpiride