Neural correlates of individual differences in aversion to risk and choice inconsistencies

Abstract

Most people tend to prefer smaller certain gains to large uncertain gains when making financial choices (risk aversion). However, attitudes toward risk vary greatly between individuals, and over time within individuals. Consistent behavior may reflect the adoption by the individual of a simple or automatized heuristic which reduces the subject’s uncertainty about the outcome of a behavioral choice. In contrast inconsistent behavior may reflect the adoption of a “fuzzy” logic, likely leaving high levels of uncertainty in the participant making the choice. Therefore, inconsistent behavior may often be associated with greater risk aversion. The use of simple/automatized heuristics may also lead to increased reliance on fast brain processes, whereas fuzzy heuristic may lead to lingering uncertainty. These two modes of processing may therefore lead to different brain dynamics. To examine these dynamics we recorded event-related brain potentials (ERPs) from 22 adults participants engaged in a task requiring choices between certain (but often smaller) gains and an uncertain (but often bigger) gains. Behavioral analyses allowed us to quantify choice consistency and risk aversion for each individual. Choice consistency was related to the amplitude of P200; risk aversion was related to modulation of the medial frontal negativity (MFN) as a function of choice uncertainty, to the amplitude of a late positive potential (LPP). These findings are consistent with the idea that differences in individuals’ behavior when making financial choices may reflect variations in the type of heuristics they adopt, which in turn may may be reflected in differences in brain dynamics.