Comparative Psychology of Frustrative Nonreward

Abstract

Research with mammals, including humans, shows that unexpected reward downshifts (omissions or reductions) can induce a negative emotional state, called frustrative nonreward, with behavioral, physiological, neurochemical, and molecular consequences. The successive negative contrast (SNC) task has been extensively used to study the effects of reward downshift. In SNC, a downshift from large to small rewards leads to a transient suppression of behavior compared to controls always exposed to small rewards. Behavioral suppression is accompanied by the release of stress hormones, ameliorated by anxiolytics and analgesics, reduced by lesions of the amygdala, and enhanced by lesions to the anterior cingulate cortex. Unlike mammals, other vertebrates exposed to reward downshifts tend to exhibit a gradual adjustment to the small reward, an effect called reversed SNC. This research is leading to a deeper understanding of the mechanisms and consequences of frustrative nonreward, including its effects on health and well-being in humans.