Economists, psychologists and neuroscientists have proposed a wide range of models of people's choices when confronted with risky options that describe how such decisions should be made (normative) or how such decisions appear to be made (descriptive). However, the actual processes by which such choices are made remain an open question. Recently, neuroscience researchers using functional magnetic resonance imaging (fMRI) have begun to examine how the human brain encodes information about some of the variables used by many models of risky decision making. These techniques have been used to identify neural signals that may be related to both the material and emotional consequences of choices, and can thus inform controversies between competing descriptive theories of risky decision making.
We will use neuroscience evidence to test between different theories or models of behavior in two areas of considerable interest to researchers and policy makers: (a) the nature of risk perception and its role in risky decision making, and (b) differences in the way people make risky decisions when basing them on repeated personal experience with the outcomes of choice options vs. basing them on statistical summary information about the choice options, typically provided by others. Our investigation of risk perception and risky choice will relate levels of brain activation in areas known to be involved in risk judgments and risky decisions to choice set characteristics and to observed judgments and choices. This will enable us to test between competing models of risky choice and to investigate the neural determinants of individual differences in risk perception and risky choice. Future studies will take such insights and apply them to risky decisions from description and uncertain decisions from personal experience made in clinical populations, in particular by schizophrenics and young substance abusers. The will help to build a neural process model of risky decision-making in normal adults, which can serve as a foundation for understanding the neural sources of impaired decision making in clinical and other at-risk populations.
