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Scientific Understanding of Consciousness |
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Self-Control in Decision-Making
Science 1 May 2009: Vol. 324. no. 5927, pp. 646 - 648 Self-Control in Decision-Making Involves Modulation of the vmPFC Valuation System Todd A. Hare,1 Colin F. Camerer,1,2 Antonio Rangel1,2 1 Division of Humanities and Social Sciences, California Institute of Technology, Pasadena, CA 91125, USA. (paraphrase) Every day, individuals make dozens of choices between an alternative with higher overall value and a more tempting but ultimately inferior option. Optimal decision-making requires self-control. We propose two hypotheses about the neurobiology of self-control: (i) Goal-directed decisions have their basis in a common value signal encoded in ventromedial prefrontal cortex (vmPFC), and (ii) exercising self-control involves the modulation of this value signal by dorsolateral prefrontal cortex (DLPFC). We used functional magnetic resonance imaging to monitor brain activity while dieters engaged in real decisions about food consumption. Activity in vmPFC was correlated with goal values regardless of the amount of self-control. It incorporated both taste and health in self-controllers but only taste in non–self-controllers. Activity in DLPFC increased when subjects exercised self-control and correlated with activity in vmPFC. We investigated which neural processes are responsible for the deployment of self-control and how these processes interact with the brain’s valuation and decision-making circuitry. We hypothesized that goal-directed decisions have their basis in a value signal encoded in the ventromedial prefrontal cortex (vmPFC). Self-control involves modulation by the dorsolateral prefrontal cortex (DLPFC) of the value signals computed in vmPFC. This hypothesis has its basis in the role of DLPFC in cognitive control, working memory, and emotion regulation. Self-control problems arise in situations where various factors (e.g., health and taste) must be integrated in vmPFC to compute goal values and that DLPFC activity is required for higher-order factors, such as health, to be incorporated into the vmPFC value signal. We speculate that the vmPFC originally evolved to forecast the short-term value of stimuli and that humans developed the ability to incorporate long-term considerations into values by giving structures such as the DLPFC the ability to modulate the basic value signal. The shortsighted valuation network includes the vmPFC, and the foresighted one includes the DLPFC. Our results suggest that the DLPFC plays a critical role in the deployment of self-control by modulating the value signal encoded in vmPFC. (end of paraphrase)
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