This grant, funded under the Human and Social Dynamics (HSD) Competition for FY 2004, provides funding for a set of studies that use functional magnetic resonance imaging (fMRI) to examine the brain systems involved in decision making. Many decisions must be made without advance knowledge of their consequences and under some degree of physical or financial risk. Whereas the cognitive processes involved in decision making under risk are well understood, the brain systems that underlie these processes have only begun to be explored. This project will examine how brain pathways for the processing of reward and punishment are involved in decision making, by imaging brain activity while individuals make decisions regarding risky gambles (for example, the choice between a sure receipt $20 or a 50/50 chance of either $50 or $0). Factors to be examined include the relation of risky and riskless decisions, the effects of extreme probabilities on risky decision making, and the dynamics of decision making in a context of changing risk. Measures of skin conductance will be obtained during imaging, so that physiological arousal can be quantified and related to behavior and brain activity. Analyses will focus on whether activity in particular brain regions related to the experience of reward or punishment will be predictive of the individual's decisions. Each subject's behavior will also be characterized using formal decision theory models, and the parameters describing this behavior will be related to brain activity.
If successful, this research will provide novel insights into how the brain makes decisions. In particular, the results will help to relate quantitative models of behavioral decision making with their neurobiological underpinnings. Knowledge about the neural basis of decision making will encourage convergence across models at the neural and cognitive levels, and will provide neuroscientists with new ways to characterize the relation between brain activity and behavior.
