Risk-dependent reward value signal in human prefrontal cortex

Abstract

When making choices under uncertainty, people usually consider both the expected value and risk of each option, and choose the one with the higher utility. Expected value increases the expected utility of an option for all individuals. Risk increases the utility of an option for risk-seeking individuals, but decreases it for risk averse individuals. In 2 separate experiments, one involving imperative (no-choice), the other choice situations, we investigated how predicted risk and expected value aggregate into a common reward signal in the human brain. Blood oxygen level dependent responses in lateral regions of the prefrontal cortex increased monotonically with increasing reward value in the absence of risk in both experiments. Risk enhanced these responses in risk-seeking participants, but reduced them in risk-averse participants. The aggregate value and risk responses in lateral prefrontal cortex contrasted with pure value signals independent of risk in the striatum. These results demonstrate an aggregate risk and value signal in the prefrontal cortex that would be compatible with basic assumptions underlying the mean-variance approach to utility. decision making ͉ fMRI ͉ utility ͉ mean-variance approach ͉ neuroeconomics

Comparison of functional near-infrared spectroscopy and electrodermal activity in assessing objective versus subjective risk during risky financial decisions

“…We grouped this subject together with the risk-seeking subjects because its CE DIFF was closer to their range of CE DIFF (-5 to -2.5) than to the range of CE DIFF of riskaverse subjects (7.5 to 15); yet, excluding the risk-neutral subject did not significantly change the results. The task identified significantly more subjects as risk-averse than risk-seeking (Fisher's Exact Test, χ² = 16.353, p ≤ 0.001), which is in agreement with our previous findings Tobler et al, 2009). Together, these data show that subjects' decisions were influenced by both risk and EV and reveal considerable individual differences in risk attitudes.…”

“…Each subject completed a previously described risky decision-making task Tobler et al, 2009) and a baseline recording. The order of the conditions was counter-balanced between subjects.…”

Consequences of Adolescent Ethanol Consumption on Risk Preference and Orbitofrontal Cortex Encoding of Reward

“…When rewards are uncertain, the magnitude of response in OFC has been shown to modulate proportionally with risk (Tobler et al, 2009), and lesions of OFC disrupt decisions that involve risk (Hsu et al, 2005). We previously found the level of OFC activity following delivery of 'certain' and 'risky' rewards varied with reward size, probability, and preference for a risky reward option in rats (Roitman and Roitman, 2010).…”

Aportes sobre el correlato neuroanatómico de la personalidad

“…Sin embargo, numerosos estudios avalan la capacidad de la LPFC de representar resultados motivacionales 38,39 . Por ejemplo, Kobayashi et al mostraron que la actividad de neuronas de la LPFC era modulada por la presencia de re-…”

“…Otros estudios demostraron que existe una correlación entre la activación de la LPFC y el valor de distintas posibilidades de elección en ciertas tareas 38,39 . Desde el punto de vista anatómico, la LPFC está conectada con varias regiones asociadas con la motivación, como aquellas nombradas previamente 41 .…”