Dissociable Neural Responses in Human Reward Systems

TLDR

Reward is a key driver of behavior, and animal studies implicate the extended limbic system and ventral striatum in responding to reinforcing stimuli. The study aimed to map neural responses to rewards and penalties in human reward systems across different psychological contexts. Functional MRI was used to scan nine healthy volunteers while they performed a gambling task involving financial rewards and penalties. Midbrain and ventral striatal activity tracked financial rewards, hippocampal activity tracked penalties, and additional regions such as the globus pallidus, thalamus, subgenual cingulate, caudate, insula, and ventral prefrontal cortex showed context‑specific responses, demonstrating dissociable neural patterns for rewards and penalties.

Abstract

Reward is one of the most important influences shaping behavior. Single-unit recording and lesion studies in experimental animals have implicated a number of regions in response to reinforcing stimuli, in particular regions of the extended limbic system and the ventral striatum. In this experiment, functional neuroimaging was used to assess neural response within human reward systems under different psychological contexts. Nine healthy volunteers were scanned using functional magnetic resonance imaging during the performance of a gambling task with financial rewards and penalties. We demonstrated neural sensitivity of midbrain and ventral striatal regions to financial rewards and hippocampal sensitivity to financial penalties. Furthermore, we show that neural responses in globus pallidus, thalamus, and subgenual cingulate were specific to high reward levels occurring in the context of increasing reward. Responses to both reward level in the context of increasing reward and penalty level in the context of increasing penalty were seen in caudate, insula, and ventral prefrontal cortex. These results demonstrate dissociable neural responses to rewards and penalties that are dependent on the psychological context in which they are experienced.