title: Separate and overlapping brain areas encode subjective value during delay and effort discounting.
abstract: Making decisions about rewards that involve delay or effort requires the integration of value and cost information. The brain areas recruited in this integration have been well characterized for delay discounting. However only a few studies have investigated how effort costs are integrated into value signals to eventually determine choice. In contrast to previous studies that have evaluated fMRI signals related to physical effort, we used a task that focused on cognitive effort. Participants discounted the value of delayed and effortful rewards. The value of cognitively effortful rewards was represented in the anterior portion of the inferior frontal gyrus and dorsolateral prefrontal cortex. Additionally, the value of the chosen option was encoded in the anterior cingulate cortex, caudate, and cerebellum. While most brain regions showed no significant dissociation between effort discounting and delay discounting, the ACC was significantly more activated in effort compared to delay discounting tasks. Finally, overlapping regions within the right orbitofrontal cortex and lateral temporal and parietal cortices encoded the value of the chosen option during both delay and effort discounting tasks. These results indicate that encoding of rewards discounted by cognitive effort and delay involves partially dissociable brain areas, but a common representation of chosen value is present in the orbitofrontal, temporal and parietal cortices.
authors.affiliation: Center for Cognitive Neuroscience, Neuroscience & Biobehavioral Disorders Program, Duke-NUS Medical School, Singapore.
authors.forename: Stijn A A
authors.initials: SA
authors.lastname: Massar
authors.affiliation: Center for Cognitive Neuroscience, Neuroscience & Biobehavioral Disorders Program, Duke-NUS Medical School, Singapore; Department of Psychology, National University of Singapore, Singapore.
authors.forename: Camilo
authors.initials: C
authors.lastname: Libedinsky
authors.affiliation: Center for Cognitive Neuroscience, Neuroscience & Biobehavioral Disorders Program, Duke-NUS Medical School, Singapore.
authors.forename: Chee
authors.initials: C
authors.lastname: Weiyan
authors.affiliation: Department of Psychology and Neuroscience, Duke University, Durham, NC, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Huettel
authors.affiliation: Center for Cognitive Neuroscience, Neuroscience & Biobehavioral Disorders Program, Duke-NUS Medical School, Singapore. Electronic address: michael.chee@duke-nus.edu.sg.
authors.forename: Michael W L
authors.initials: MW
authors.lastname: Chee
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002421:Caudate Nucleus / Q000502:physiology*; D002531:Cerebellum / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology*; D065786:Delay Discounting / Q000502:physiology; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D012201:Reward; D055815:Young Adult
keywords: Decision making; Delay discounting; Effort discounting; Reward; Subjective value; fMRI