In our studies of motivation, we have found that monkeys work faster and with fewer errors when a cue indicates that a juice reward will be delivered immediately after the next correct response than when the cue indicates that additional trials will be needed. Single neurons in the ventral striatum signal the rewarded trial when it follows one or more unrewarded trials, thus providing a neural signal that could reinforce complex behavior. The neuronal responses are thus directly related to the associative learning of the meaning of the cue in a complex behavioral task. Changing the meaning of the cue is accompanied by a parallel change in neural activity. Specifically, the neurons keep track of whether the animal is at the beginning, end, or in the course of a behavioral sequence that ultimately leads to reward. The neurons that responded when intravenous cocaine was used as the reward were different from those that responded to juice, and they responded equally strongly whether the trial was rewarded or not, indicating that neuronal responses related to cocaine are not simply enhanced normal signals, but are qualitatively different.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Intramural Research (Z01)
Project #
1Z01MH002619-04
Application #
5203778
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
4
Fiscal Year
1995
Total Cost
Indirect Cost
Name
U.S. National Institute of Mental Health
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Bouret, Sebastien; Richmond, Barry J (2009) Relation of locus coeruleus neurons in monkeys to Pavlovian and operant behaviors. J Neurophysiol 101:898-911
Minamimoto, Takafumi; La Camera, Giancarlo; Richmond, Barry J (2009) Measuring and modeling the interaction among reward size, delay to reward, and satiation level on motivation in monkeys. J Neurophysiol 101:437-47
Simmons, Janine M; Saad, Ziad S; Lizak, Martin J et al. (2008) Mapping prefrontal circuits in vivo with manganese-enhanced magnetic resonance imaging in monkeys. J Neurosci 28:7637-47
Simmons, Janine M; Richmond, Barry J (2008) Dynamic changes in representations of preceding and upcoming reward in monkey orbitofrontal cortex. Cereb Cortex 18:93-103
La Camera, Giancarlo; Richmond, Barry J (2008) Modeling the violation of reward maximization and invariance in reinforcement schedules. PLoS Comput Biol 4:e1000131
Simmons, Janine M; Ravel, Sabrina; Shidara, Munetaka et al. (2007) A comparison of reward-contingent neuronal activity in monkey orbitofrontal cortex and ventral striatum: guiding actions toward rewards. Ann N Y Acad Sci 1121:376-94
Sugase-Miyamoto, Yasuko; Richmond, Barry J (2007) Cue and reward signals carried by monkey entorhinal cortex neurons during reward schedules. Exp Brain Res 181:267-76
Lerchner, Alexander; La Camera, Giancarlo; Richmond, Barry (2007) Knowing without doing. Nat Neurosci 10:15-7
Mizuhiki, Takashi; Richmond, Barry J; Shidara, Munetaka (2007) Mode changes in activity of single neurons in anterior insular cortex across trials during multi-trial reward schedules. Neurosci Res 57:587-91
Nakahara, Hiroyuki; Amari, Shun-ichi; Richmond, Barry J (2006) A comparison of descriptive models of a single spike train by information-geometric measure. Neural Comput 18:545-68

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