Present address: Department of Food and Health Sciences, Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto 862-8502, Japan.
Neuronal basis for evaluating selected action in the primate striatum
Article first published online: 22 JUL 2011
© 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd
European Journal of Neuroscience
Volume 34, Issue 3, pages 489–506, August 2011
How to Cite
Yamada, H., Inokawa, H., Matsumoto, N., Ueda, Y. and Kimura, M. (2011), Neuronal basis for evaluating selected action in the primate striatum. European Journal of Neuroscience, 34: 489–506. doi: 10.1111/j.1460-9568.2011.07771.x
- Issue published online: 1 AUG 2011
- Article first published online: 22 JUL 2011
- Received 16 February 2011, revised 23 April 2011, accepted 18 May 2011
- basal ganglia;
- caudate nucleus;
Humans and animals optimize their behavior by evaluating outcomes of individual actions and predicting how much reward the actions will yield. While the estimated values of actions guide choice behavior, the choices are also governed by other behavioral norms, such as rules and strategies. Values, rules and strategies are represented in neuronal activity, and the striatum is one of the best qualified brain loci where these signals meet. To understand the role of the striatum in value- and strategy-based decision-making, we recorded striatal neurons in macaque monkeys performing a behavioral task in which they searched for a reward target by trial-and-error among three alternatives, earned a reward for a target choice, and then earned additional rewards for choosing the same target. This task allowed us to examine whether and how values of targets and strategy, which were defined as negative-then-search and positive-then-repeat (or win-stay-lose-switch), are represented in the striatum. Large subsets of striatal neurons encoded positive and negative outcome feedbacks of individual decisions and actions. Once monkeys made a choice, signals related to chosen actions, their values and search- or repeat-type actions increased and persisted until the outcome feedback appeared. Subsets of neurons exhibited a tonic increase in activity after the search- and repeat-choices following negative and positive feedback in the last trials as the task strategy monkeys adapted. These activity profiles as a heterogeneous representation of decision variables may underlie a part of the process for reinforcement- and strategy-based evaluation of selected actions in the striatum.