Distributed neural representation of expected value.
Anticipated reward magnitude and probability comprise dual components of expected value (EV), a cornerstone of economic and psychological theory. However, the neural mechanisms that compute EV have not been characterized. Using event-related functional magnetic resonance imaging, we examined neural activation as subjects anticipated monetary gains and losses that varied in magnitude and probability. Group analyses indicated that, although the subcortical nucleus accumbens (NAcc) activated proportional to anticipated gain magnitude, the cortical mesial prefrontal cortex (MPFC) additionally activated according to anticipated gain probability. Individual difference analyses indicated that, although NAcc activation correlated with self-reported positive arousal, MPFC activation correlated with probability estimates. These findings suggest that mesolimbic brain regions support the computation of EV in an ascending and distributed manner: whereas subcortical regions represent an affective component, cortical regions also represent a probabilistic component, and, furthermore, may integrate the two.
Knutson
Brian
B
Department of Psychology, Stanford University, Stanford, California 94305, USA. knutson@psych.stanford.edu
Taylor
Jonathan
J
Kaufman
Matthew
M
Peterson
Richard
R
Glover
Gary
G
D000328:Adult; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009714:Nucleus Accumbens / Q000098:blood supply / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D017397:Prefrontal Cortex / Q000098:blood supply / Q000502:physiology*; D011336:Probability; D012016:Reference Values; D012044:Regression Analysis; D012201:Reward; D013997:Time Factors
D010100:Oxygen