Behavioral Social Neuroscience Seminar

A crucial step of economic decision-making is the valuation of available options. There is growing evidence that subjective values are encoded in a dedicated brain valuation system (BVS), witch includes the ventromedial prefrontal cortex (VMPFC) as a key player. In this talk, I will highlight a few properties of the VMPFC signal that might be worth considering in order to understanding its contribution to value judgment. First, it is the VMPFC response peak that encodes subjective value, and not the differential from the baseline. This means that, due to auto-correlation in the brain signal, trial-by-trial fluctuations in the baseline, either spontaneous or context-dependent, will affect how much subjects value the proposed items. Second, confidence in the value judgment is also automatically integrated in the VMPFC signal, in addition to the value itself. This suggests that the VMPFC aggregates how much subjects value the proposed item and how much they value their own response. These distortions of the brain valuation signal might account for deviations to rationality such as misattribution or contextual dependency. Finally, I will illustrate some situations in which the construction of subjective values involves an interaction between the BVS and other brain systems, which might account for psychological phenomena such as mimetic desire (why we want what the others want) and choice impulsivity (why we succumb to the temptation of immediate pleasures).