The Known Unknowns: Neural Representation of Second-Order Uncertainty, and Ambiguity
Open Access
- 30 March 2011
- journal article
- research article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 31 (13), 4811-4820
- https://doi.org/10.1523/jneurosci.1452-10.2011
Abstract
Predictions provided by action-outcome probabilities entail a degree of (first-order) uncertainty. However, these probabilities themselves can be imprecise and embody second-order uncertainty. Tracking second-order uncertainty is important for optimal decision making and reinforcement learning. Previous functional magnetic resonance imaging investigations of second-order uncertainty in humans have drawn on an economic concept of ambiguity, where action-outcome associations in a gamble are either known (unambiguous) or completely unknown (ambiguous). Here, we relaxed the constraints associated with a purely categorical concept of ambiguity and varied the second-order uncertainty of gambles continuously, quantified as entropy over second-order probabilities. We show that second-order uncertainty influences decisions in a pessimistic way by biasing second-order probabilities, and that second-order uncertainty is negatively correlated with posterior cingulate cortex activity. The category of ambiguous (compared with nonambiguous) gambles also biased choice in a similar direction, but was associated with distinct activation of a posterior parietal cortical area; an activation that we show reflects a different computational mechanism. Our findings indicate that behavioral and neural responses to second-order uncertainty are distinct from those associated with ambiguity and may call for a reappraisal of previous data.This publication has 57 references indexed in Scilit:
- An “As Soon As Possible” Effect in Human Intertemporal Decision Making: Behavioral Evidence and Neural MechanismsJournal of Neurophysiology, 2010
- Bayesian model selection for group studiesNeuroImage, 2009
- Dissociable neural representations of future reward magnitude and delay during temporal discountingNeuroImage, 2009
- Cortical midline involvement in autobiographical memoryNeuroImage, 2009
- Neural substrates of reward magnitude, probability, and risk during a wheel of fortune decision-making taskNeuroImage, 2009
- Greater activation of the “default” brain regions predicts stop signal errorsNeuroImage, 2007
- The neural correlates of subjective value during intertemporal choiceNature Neuroscience, 2007
- Optimized EPI for fMRI studies of the orbitofrontal cortex: compensation of susceptibility-induced gradients in the readout directionMagnetic Resonance Materials in Physics, Biology and Medicine, 2007
- Reward Value Coding Distinct From Risk Attitude-Related Uncertainty Coding in Human Reward SystemsJournal of Neurophysiology, 2007
- Image Distortion Correction in fMRI: A Quantitative EvaluationNeuroImage, 2002