title: Selective ablations reveal that orbital and lateral prefrontal cortex play different roles in estimating predicted reward value.
abstract: Subregions of prefrontal cortex are important for estimating reward values and using these values to guide behavior. The present studies directly tested whether orbital prefrontal cortex (O-PFC) and lateral prefrontal cortex (L-PFC) are necessary for evaluating trial-to-trial changes in the reward values predicted by visual cues. We have compared intact rhesus monkeys, those with bilateral O-PFC lesions (n = 3), and those with bilateral L-PFC lesions (n = 3). We used three versions of a visually cued color discrimination task: we varied reward size, delay to reward, or both. O-PFC lesions altered estimations of predicted reward value in all versions of the task. L-PFC lesions disrupted performance only when both reward size and delay to reward were varied together. Neither lesion directly affected basic internal drive states (satiation curves). Our results suggest that O-PFC is essential for establishing independent, context-specific scales with which predicted reward values are measured. L-PFC appears necessary for integration of predicted reward value across these different scales.
authors.affiliation: National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892-4415, USA.
authors.forename: Janine M
authors.initials: JM
authors.lastname: Simmons
authors.forename: Takafumi
authors.initials: T
authors.lastname: Minamimoto
authors.forename: Elisabeth A
authors.initials: EA
authors.lastname: Murray
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Richmond
mesh_terms: D000818:Animals; D001931:Brain Mapping / Q000379:methods; D003118:Color Perception / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011237:Predictive Value of Tests; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012201:Reward