Abstract
A great deal of behavioral and economic research suggests that the value attached to a reward stands in inverse relation to the amount of effort required to obtain it, a principle known as effort discounting. In the present article, we present the first direct evidence for a neural analogue of effort discounting. We used fMRI to measure neural responses to monetary rewards in the human nucleus accumbens (NAcc), a structure previously demonstrated to encode reference-dependent reward information. The magnitude of accumbens activation was found to vary with both reward outcome and the degree of mental effort demanded to obtain individual rewards. For a fixed level of reward, the NAcc was less strongly activated following a high-demand for effort than following a low demand. The magnitude of this effect was noted to correlate with preceding activation in the dorsal anterior cingulate cortex, a region that has been proposed to monitor information-processing demands and to mediate in the subjective experience of effort.
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This study was funded by Grant P50 MH062196 from the National Institute of Mental Health to the first author. The data for this study were collected when all three authors were at the University of Pennsylvania; data analysis was conducted after all three authors moved to Princeton University.
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Botvinick, M.M., Huffstetler, S. & McGuire, J.T. Effort discounting in human nucleus accumbens. Cognitive, Affective, & Behavioral Neuroscience 9, 16–27 (2009). https://doi.org/10.3758/CABN.9.1.16
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DOI: https://doi.org/10.3758/CABN.9.1.16