Doctoral Dissertation Research in DRMS: The Role of the Dorsolateral Prefrontal Cortex in Risky Choice.

Neuroeconomic research demonstrates that temporary suppression of the right dorsolateral prefrontal cortex (DLPFC) with repetitive transcranial magnetic stimulation (rTMS) leads experimental subjects to choose riskier, but potentially larger reward options over a less risky reward options. This finding has been interpreted as suggesting that the ability to override or inhibit the drive to choose tempting but riskier choices lies in a specific region of the brain ? the lateral prefrontal cortex. However, the findings reveal that, in addition to choosing more risky options following prefrontal suppression, the probability of choosing a particular option approaches chance level. Thus, an alternative interpretation of the evidence is that, as a result of suppression of the DLPFC, subjects have greater difficulty discriminating between the subjective values of the two options and choosing the highest valued alternative. This Doctoral Dissertation Improvement grant will enable the co-PI to test these alternative hypotheses of lateral prefrontal cortex function against each other by suppressing activity in this brain region with rTMS immediately before healthy human participants perform a choice task in which they must make choices between certain and risky options with varying relative subjective values. The results will reveal whether disruption of the lateral prefrontal cortex specifically modulates risk taking or helps individuals compare subjective values and select the most valued option. In terms of broader impacts, this research will inform solutions for improving maladaptive decision making in the wide range of situations (e.g. insurance, investing, health decisions) that depend upon perceptions of risk.