Neuronal Activity Representing Temporal Prediction of Reward in the Primate Prefrontal Cortex

• Published in: Journal of neurophysiology Vol. 93; no. 6; pp. 3687 - 3692
• Main Authors: Tsujimoto, Satoshi, Sawaguchi, Toshiyuki
• Format: Journal Article
• Language: English
• Published: United States Am Phys Soc 01.06.2005
• Subjects: Action Potentials - physiology; Analysis of Variance; Animals; Behavior, Animal; Cues; Electric Stimulation; Macaca mulatta; Male; Neurons - physiology; Prefrontal Cortex - cytology; Prefrontal Cortex - physiology; Psychomotor Performance - physiology; Reaction Time; Reward; Saccades - physiology; Space Perception - physiology; Time Factors
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.01149.2004

1 Laboratory of Cognitive Neurobiology, Hokkaido University Graduate School of Medicine, Sapporo; and 2 Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, Japan Submitted 8 November 2004; accepted in final form 2 January 2005 Temporal prediction of future events, especially regarding reward delivery, is critical for controlling/learning purposeful behavior. The dorsolateral prefrontal cortex (DLPFC) has been considered to be involved in behavioral control based on prospective coding for future events, including reward. Thus this area is likely to have a neuronal mechanism responsible for temporal prediction of forthcoming reward. To address this hypothesis, we recorded the neuronal activity from the DLPFC of macaque monkeys while they performed an oculomotor delayed-response task under two conditions regarding the time of reward delivery. In this task, when the subjects made a correct response, the reward was delivered after a reward-delay period of 0.5 or 2 s. At the behavioral level, the onset latency for saccades was significantly faster in the shorter reward-delay trials (0.5 s) than in longer reward-delay trials (2 s), indicating that our subjects actually predicted the time of reward delivery. At the neuronal level, we found that many DLPFC neurons showed differential activity depending on the predicted time of reward delivery during the cue and/or delay periods. These results suggest that a fraction of neurons in the DLPFC represent the temporal prediction of reward and probably a variety of other future events. Address for reprint requests and other correspondence: T. Sawaguchi, Laboratory of Cognitive Neurobiology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638, Japan (E-mail: toshi-sw{at}med.hokudai.ac.jp )