Decision making in the Balloon Analogue Risk Task (BART): Anterior cingulate cortex signals loss aversion but not the infrequency of risky choices

The inferior frontal gyrus/anterior insula (IFG/AI) and anterior cingulate cortex (ACC) are key regions involved in risk appraisal
during decision making, but accounts of how these regions contribute to decision making under risk remain contested. To help
clarify the roles of these and other related regions, we used a modified version of the Balloon Analogue Risk Task (Lejuez
et al., Journal of Experimental Psychology: Applied, 8, 75–84, 2002) to distinguish between decision-making and feedback-related processes when participants decided to pursue a gain as the
probability of loss increased parametrically. Specifically, we set out to test whether the ACC and IFG/AI regions correspond
to loss aversion at the time of decision making in a way that is not confounded with either reward-seeking or infrequency
effects. When participants chose to discontinue inflating the balloon (win option), we observed greater ACC and mainly bilateral
IFG/AI activity at the time of decision as the probability of explosion increased, consistent with increased loss aversion
but inconsistent with an infrequency effect. In contrast, we found robust vmPFC activity when participants chose to continue
inflating the balloon (risky option), consistent with reward seeking. However, in the cingulate and in mainly bilateral IFG
regions, blood-oxygenation-level-dependent activation decreased when participants chose to inflate the balloon as the probability
of explosion increased, findings that are consistent with a reduced loss aversion signal. Our results highlight the existence
of distinct reward-seeking and loss-averse signals during decision making, as well as the importance of distinguishing between
decision and feedback signals.