A neural mechanism underlying failure of optimal choice with multiple alternatives

Ka Hung Bolton Chau, Nils Kolling, Laurence T. Hunt, Mark E. Walton, Matthew F.S. Rushworth

Research output: Journal article publicationJournal articleAcademic researchpeer-review

66 Citations (Scopus)

Abstract

Despite widespread interest in neural mechanisms of decision-making, most investigations focus on decisions between just two options. Here we adapt a biophysically plausible model of decision-making to predict how a key decision variable, the value difference signal - encoding how much better one choice is than another - changes with the value of a third, but unavailable, alternative. The model predicts a surprising failure of optimal decision-making: greater difficulty choosing between two options in the presence of a third very poor, as opposed to very good, alternative. Both investigation of human decision-making and functional magnetic resonance imaging-based measurements of value difference signals in ventromedial prefrontal cortex (vmPFC) bore out this prediction. The vmPFC signal decreased in the presence of low-value third alternatives, and vmPFC effect sizes predicted individual variation in suboptimal decision-making in the presence of multiple alternatives. The effect contrasts with that of divisive normalization in parietal cortex.
Original languageEnglish
Pages (from-to)463-470
Number of pages8
JournalNature Neuroscience
Volume17
Issue number3
DOIs
Publication statusPublished - 1 Mar 2014
Externally publishedYes

ASJC Scopus subject areas

  • Neuroscience(all)

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