Is There a Common Network for Processing Reward and Aversion in the Brain?

Abstract

How do our brains process and attach positive and negative value to the objects around us, the sensations we feel, and the experiences that we have? One method of examining these questions is to detect, using functional magnetic resonance imaging (fMRI), which areas of the human brain are activated when subjects are exposed to rewarding and aversive stimuli. Although many fMRI studies have concentrated on identifying a network of areas that become active in processing either reward or aversion, there is evidence of significant overlap between the “reward” and “aversion” networks, suggesting that the brain might process rewarding and aversive stimuli in a similar manner regardless of valence. Thus, a meta-analysis of fMRI studies involving rewarding and aversive stimuli was undertaken to determine the areas of the brain that are commonly and differentially activated by reward and aversion. The preliminary results indicate that regions of the prefrontal cortex, anterior cingulate cortex, amygdala, nucleus accumbens, hippocampus, and basal ganglia were commonly activated by rewarding and aversive stimuli, while areas including the insula, midcingulate cortex, and parts of the hippocampus were differentially activated. Locating such commonalities and differences might help in our understanding of how the brain ascribes value to our environment.