Neuronal basis for evaluating selected action in the primate striatum
Neuronal basis for evaluating selected action in the primate striatum
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DOI：
10.1111/j.1460-9568.2011.07771.x
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发表时间：
2011-08
影响因子：
3.4
通讯作者：
H. Yamada;H. Inokawa;N. Matsumoto;Y. Ueda;M. Kimura
中科院分区：
文献类型：
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作者：
H. Yamada;H. Inokawa;N. Matsumoto;Y. Ueda;M. Kimura
人类和动物通过评估个人行为的结果并预测这些行为将产生多少回报来优化他们的行为。虽然行动的估计值指导选择行为，但选择也受到其他行为规范的约束，如规则和策略。价值观、规则和策略在神经元活动中表现出来，而纹状体是这些信号相遇的最佳大脑部位之一。为了了解纹状体在基于价值和策略的决策中的作用，我们记录了猕猴的纹状体神经元执行行为任务，在该任务中，它们通过在三个备选方案中试错来寻找奖励目标，为目标选择赢得奖励，然后为选择相同的目标获得额外的奖励。这项任务使我们能够检查目标和策略的价值观是否以及如何在纹状体中表现出来，这些价值观被定义为负-然后-搜索和正-然后-重复（或赢-留-输-转换）。纹状体神经元的大子集编码个人决策和行动的积极和消极结果反馈。一旦猴子做出选择，与所选择的行为、它们的价值观和搜索或重复类型的行为相关的信号就会增加并持续下去，直到结果反馈出现。在最后一次试验中，当猴子适应任务策略时，在负反馈和正反馈之后的搜索和重复选择之后，神经元的子集表现出活动的紧张性增加。这些活动特征作为决策变量的异质性表示，可能是纹状体中选定动作的强化和基于策略的评估过程的一部分。
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.