title: Neuronal activities in the reward phase in primary and higher-order gustatory cortices of monkeys.
abstract: We examined neuronal activities in the reward phase of a taste discrimination GO/NOGO task and the reversal from the primary (PGC; areas G, 3 and 1-2) and higher order gustatory cortices (HGC, PrCO and OFC) in the monkey. Sucrose was given as reward for both GO (lever pressing during LED) and NOGO responses when correct. Three ON responses, synchronous with sucrose onset at correct or LED offset at incorrect trials were found: C- and I- types increased discharges only at correct or incorrect trials, while C-I type changed discharges at both. Of the latter two classes were noted; Class I increased discharges at correct and decreased them at incorrect trials, and Class II increased discharges at both. C-type and Class I were most numerous in both PGC and HGC except for the OFC in which Class II responses predominated. I-type was rare. Onset latencies at correct and incorrect trials were significantly correlated in the HGC but not in the PGC. It was suggested that C-type responses represented the gustatory nature of reward, I-type neurons error signals, and that Class I of C-I type indicated the arrival or omission of the reward, and Class II anticipation of reward delivery.
authors.affiliation: Department of Sensory and Cognitive Physiology, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 860-8556, Japan. ifuku@kumamoto-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Ifuku
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: S
authors.initials: S
authors.lastname: Hirata
authors.forename: H
authors.initials: H
authors.lastname: Ogawa
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000166:cytology*; D002755:Choice Behavior / Q000502:physiology; D003463:Cues; D004193:Discrimination Learning / Q000502:physiology*; D005260:Female; D000882:Haplorhini; D009474:Neurons / Q000145:classification / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012201:Reward; D013649:Taste / Q000502:physiology*