Explicit neural signals reflecting reward uncertainty
Open Access
- 1 October 2008
- journal article
- Published by The Royal Society in Philosophical Transactions Of The Royal Society B-Biological Sciences
- Vol. 363 (1511), 3801-3811
- https://doi.org/10.1098/rstb.2008.0152
Abstract
The acknowledged importance of uncertainty in economic decision making has stimulated the search for neural signals that could influence learning and inform decision mechanisms. Current views distinguish two forms of uncertainty, namely risk and ambiguity, depending on whether the probability distributions of outcomes are known or unknown. Behavioural neurophysiological studies on dopamine neurons revealed a risk signal, which covaried with the standard deviation or variance of the magnitude of juice rewards and occurred separately from reward value coding. Human imaging studies identified similarly distinct risk signals for monetary rewards in the striatum and orbitofrontal cortex (OFC), thus fulfilling a requirement for the mean variance approach of economic decision theory. The orbitofrontal risk signal covaried with individual risk attitudes, possibly explaining individual differences in risk perception and risky decision making. Ambiguous gambles with incomplete probabilistic information induced stronger brain signals than risky gambles in OFC and amygdala, suggesting that the brain's reward system signals the partial lack of information. The brain can use the uncertainty signals to assess the uncertainty of rewards, influence learning, modulate the value of uncertain rewards and make appropriate behavioural choices between only partly known options.Keywords
This publication has 50 references indexed in Scilit:
- Reward Value Coding Distinct From Risk Attitude-Related Uncertainty Coding in Human Reward SystemsJournal of Neurophysiology, 2007
- The somatic marker hypothesis: A critical evaluationNeuroscience & Biobehavioral Reviews, 2006
- Neurons in the orbitofrontal cortex encode economic valueNature, 2006
- Basic Principles of Asset Pricing Theory: Evidence from Large-Scale Experimental Financial Markets *European Finance Review, 2004
- Discrete Coding of Reward Probability and Uncertainty by Dopamine NeuronsScience, 2003
- A Neural Substrate of Prediction and RewardScience, 1997
- Insensitivity to future consequences following damage to human prefrontal cortexCognition, 1994
- The application of statistical decision theory to animal behaviourJournal of Theoretical Biology, 1980
- A model for Pavlovian learning: Variations in the effectiveness of conditioned but not of unconditioned stimuli.Psychological Review, 1980
- Risk, Ambiguity, and the Savage AxiomsThe Quarterly Journal of Economics, 1961