Striatal topography of probability and magnitude information for decisions under uncertainty

Abstract

Most decisions involve some element of uncertainty. When the outcomes of these decisions have different likelihoods of occurrence, the decision-maker must consider both the magnitude of each outcome and the probability of its occurrence, but how do individual decision makers combine the two dimensions of magnitude and probability? Here, we approach the problem by separating in time the presentation of magnitude and probability information, and focus the analysis of fMRI activations on the first piece of information only. Thus, we are able to identify distinct neural circuits for the two dimensions without the confounding effect of divided attention or the cognitive operation of combining them. We find that magnitude information correlates with the size of the response of the ventral striatum while probability information correlates with the response in the dorsal striatum. The relative responsiveness of these two striatal regions correlates with the behavioral tendency to weight one more than the other. The results are consistent with a second-order process of information aggregation in which individuals make separate judgments for magnitude and probability and then integrate those judgments.

Perceiving Prospects Properly

“…By requiring the perception strategy m ( p; s) to depend only on p and s , we constrain Nature to choose a heuristic that performs well on average across all possible rewards. This approach is consistent with neuroscientific findings that responses to changes in probabilities are associated with activity in regions of the brain different from those that respond to changes in rewards, suggesting that probabilities and rewards are processed separately (see Knutson et al 2005;Berns et al 2008;Berns and Bell 2012).…”

Valence and magnitude ambiguity in feedback processing

“…Berns and Bell (2012) point out that even when the two dimensions of outcome feedback are presented simultaneously, participants still have to read them sequentially. Therefore, feedback processing in a task which present valence and magnitude simultaneously also contains an initial encoding stage and a follow‐up integration stage (Philiastides, Biele, Vavatzanidis, Kazzer, & Heekeren, 2010).…”

“…Berns and Bell (2012) has pointed out that when different dimensions of information are presented simultaneously, it is impossible to know how individuals allocate their attention to each dimension. One of our previous studies employed an experimental paradigm that dissociated the presentations of valence and magnitude (Gu et al., 2011).…”

Disruption of Orbitofronto-Striatal Functional Connectivity Underlies Maladaptive Persistent Behaviors in Alcohol-Dependent Patients

“…The dorsal striatum has been reported to encode information related to probability, whereas the ventral striatum has been consistently linked with processing information related to magnitude 17. The diverse functional connectivity among these components should contribute to the individual's differences in decision making.…”