title: PFC neurons reflect categorical decisions about ambiguous stimuli.
abstract: We examined whether PFC neuron activity reflects categorical decisions in monkeys categorizing ambiguous stimuli. A morphing system was used to systematically vary stimulus shape and precisely define category boundaries. Ambiguous stimuli were centered on a category boundary, that is, they were a mix of 50% of two prototypes and therefore had no category information, so monkeys guessed at their category membership. We found that the monkeys' trial-by-trial decision about the category membership of an ambiguous image was reflected in PFC activity. Activity to the same ambiguous image differed significantly, depending on which category the monkey had assigned it to. This effect only occurred when that scheme was behaviorally relevant. These indicate that PFC activity reflects categorical decisions.
authors.affiliation: Massachusetts Institute of Technology.
authors.forename: Jefferson E
authors.initials: JE
authors.lastname: Roy
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Buschman
authors.forename: Earl K
authors.initials: EK
authors.lastname: Miller
mesh_terms: D000818:Animals; D003657:Decision Making; D008253:Macaca mulatta; D009474:Neurons / Q000502:physiology*; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000166:cytology / Q000502:physiology*; D011930:Reaction Time