title: Neural signatures of economic preferences for risk and ambiguity.
abstract: People often prefer the known over the unknown, sometimes sacrificing potential rewards for the sake of surety. Overcoming impulsive preferences for certainty in order to exploit uncertain but potentially lucrative options may require specialized neural mechanisms. Here, we demonstrate by functional magnetic resonance imaging (fMRI) that individuals' preferences for risk (uncertainty with known probabilities) and ambiguity (uncertainty with unknown probabilities) predict brain activation associated with decision making. Activation within the lateral prefrontal cortex was predicted by ambiguity preference and was also negatively correlated with an independent clinical measure of behavioral impulsiveness, suggesting that this region implements contextual analysis and inhibits impulsive responses. In contrast, activation of the posterior parietal cortex was predicted by risk preference. Together, this novel double dissociation indicates that decision making under ambiguity does not represent a special, more complex case of risky decision making; instead, these two forms of uncertainty are supported by distinct mechanisms.
authors.affiliation: Brain Imaging and Analysis Center, Duke University Medical Center, Durham, North Carolina 27710, USA. scott.huettel@duke.edu
authors.forename: Scott A
authors.initials: SA
authors.lastname: Huettel
authors.forename: C Jill
authors.initials: CJ
authors.lastname: Stowe
authors.forename: Evan M
authors.initials: EM
authors.lastname: Gordon
authors.forename: Brent T
authors.initials: BT
authors.lastname: Warner
authors.forename: Michael L
authors.initials: ML
authors.lastname: Platt
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D003662:Decision Theory; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D012201:Reward; D012309:Risk-Taking; D013223:Statistics as Topic; D035501:Uncertainty; D014796:Visual Perception / Q000502:physiology
chemical_list: D010100:Oxygen