Ambiguous Outcome Magnitude in Economic Decision Making with Low and High Monetary Stakes

Most of life’s decisions involve risk and uncertainty regarding whether reward or loss will follow. A major approach to understanding decision-making under these circumstances comes from economics research. While many economic decision-making experiments have focused on gains/losses and risk (<100% probability of a given outcome), relatively few have studied ambiguity (i.e., uncertainty about the degree of risk or magnitude of gains/losses). Within ambiguity, most studies have focused on ambiguous risk (uncertainty regarding likelihood of outcomes), but few studies have investigated ambiguous outcome magnitude (i.e., uncertainty regarding how small/large the gain/loss will be). In the present report, we investigated the effects of ambiguous outcome magnitude, risk, and gains/losses in an economic decision-making task with low stakes (Study 1; $3.60-$5.70; N = 367) and high stakes (Study 2; $6-$48; N = 210) using the same participants in Study 2 as in Study 1. We conducted computational modeling to determine individuals’ preferences/aversions for ambiguous outcome magnitudes, risk, and gains/losses. Our results show that increasing stakes increases ambiguous gain aversion, unambiguous loss aversion, and unambiguous risk aversion, but increases ambiguous loss preference. These results suggest that as stakes increase, people tend to avoid uncertainty and loss in most domains but prefer ambiguous loss.

How motivational signals disrupt metacognitive signals in the human VMPFC

A growing body of evidence suggests that, during decision-making, BOLD signal in the VMPFC correlates both with motivational variables – such as incentives and expected values – and metacognitive variables – such as confidence judgments, which reflect the subjective probability of being correct. At the behavioral level, we recently demonstrated that the value of monetary stakes bias confidence judgments, with gain (respectively loss) prospects increasing (respectively decreasing) confidence judgments, even for similar levels of difficulty and performance. If and how this value-confidence interaction is also reflected in VMPFC signals remains unknown. Here, we used an incentivized perceptual decision-making task that dissociates key decision-making variables, thereby allowing to test several hypotheses about the role of the VMPFC in the incentive-confidence interaction. While initial analyses seemingly indicate that VMPFC combines incentives and confidence to form an expected value signal, we falsified this conclusion with a meticulous dissection of qualitative activation patterns. Rather, our results show that strong VMPFC confidence signals observed in trials with gain prospects are disrupted in trials with no – or negative (loss) monetary prospects. Deciphering how decision variables are represented and interact at finer scales (population codes, individual neurons) seems necessary to better understand biased (meta)cognition.