The Neural Substrates of Reward Processing in Humans: The Modern Role of fMRI

Abstract

Experimental work in animals has identified numerous neural structures involved in reward processing and reward-dependent learning. Until recently, this work provided the primary basis for speculations about the neural substrates of human reward processing. The widespread use of neuroimaging technology has changed this situation dramatically over the past decade through the use of PET and fMRI. Here, the authors focus on the role played by fMRI studies, where recent work has replicated the animal results in human subjects and has extended the view of putative reward-processing neural structures. In particular, fMRI work has identified a set of reward-related brain structures including the orbitofrontal cortex, amygdala, ventral striatum, and medial prefrontal cortex. Moreover, the human experiments have probed the dependence of human reward responses on learned expectations, context, timing, and the reward dimension. Current experiments aim to assess the function of human reward-processing structures to determine how they allow us to predict, assess, and act in response to rewards. The authors review current accomplishments in the study of human reward processing and focus their discussion on explanations directed particularly at the role played by the ventral striatum. They discuss how these findings may contribute to a better understanding of deficits associated with Parkinson's disease.

Social comparison in the brain: A coordinate‐based meta‐analysis of functional brain imaging studies on the downward and upward comparisons

“…Our meta-analysis first identified a consistent involvement of the VS and vmPFC in downward comparison. Based on the role of these regions in reward processing [Carlson et al, 2011;Cromwell et al, 2005;McClure et al, 2004;Rushworth et al, 2011;Sescousse et al, 2015], our findings dovetail with the notion that downward comparison is experienced as rewarding [Bault et al, 2011;Dvash et al, 2010;Fliessbach et al, 2007]. Prior studies have shown the involvement of the VS in the processing of other types of social rewards, including good reputation [Izuma et al, 2008;Meshi et al, 2013] and social approval [Izuma et al, 2010].…”

Neural correlates of a ‘pessimistic’ attitude when anticipating events of unknown emotional valence

“…This underlines views of its function of a more general role in emotion processing as for emotional arousal or intensity without a valence specificity (Baxter and Murray, 2002;Anderson et al, 2003;Gottfried et al, 2003;McClure et al, 2004).…”

Self-related awareness and emotion regulation

“…In parallel, amygdalar activation as an indicator for emotional arousal (McClure et al, 2004) was diminished during affect labeling of external cues with increasing mindfulness . Novices in mindfulness strategies showed functional connectivity between MPFC and insula (Farb et al, 2007), the latter indicating an association with bodily signals (Critchley et al, 2004).…”