Influence of reward expectation on behavior-related neuronal activity in primate striatum
Influence of reward expectation on behavior-related neuronal activity in primate striatum
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DOI：
10.1152/jn.1998.80.2.947
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发表时间：
1998-08-01
影响因子：
2.5
通讯作者：
Schultz, W
中科院分区：
文献类型：
--
作者：
Hollerman, JR;Tremblay, L;Schultz, W
奖励是自愿行为的重要目标。本研究旨在探讨预期奖励如何影响前纹状体中与行为相关的神经元活动。在一个延迟的go-nogo任务中，猴子执行或停止一个伸手的动作，并获得液体或声音作为强化。一个初始的指示图片显示了要进行的行为反应和在随后的触发刺激后要获得的强化物。动作根据指令预测的强化物而变化，这表明动物对这两种结果的预期不同。在尾状核前部、壳核和腹侧纹状体的近1500个神经元中，约有250个神经元表现出典型的任务相关激活，反映了对指令和触发的期望，以及行为反应的准备、启动和执行。引人注目的是，大多数与任务相关的激活只发生在试验结束时提供液体奖励时，而不是在强化声音时。接近奖励时间的激活表现出对液体奖励的类似偏好，而不是强化声音，这表明它与试验的动机结果的预期或检测有关，而不是与“正确”或“试验结束”信号有关。相比之下，在当前的任务中，与强化类型无关的激活相对较少。总之，在前纹状体中研究的许多行为相关神经元受到即将到来的初级液体奖励的影响，并且似乎没有以动机中性的方式编码行为。相反，这些神经元将预期结果的信息整合到与行为相关的活动中。在奖赏发生前几秒受奖赏影响的激活可能构成奖赏对行为反应的逆行效应的神经元基础。
Rewards constitute important goals for voluntary behavior. This study aimed to investigate how expected rewards influence behavior-related neuronal activity in the anterior striatum. In a delayed go-nogo task, monkeys executed or withheld a reaching movement and obtained liquid or sound as reinforcement. An initial instruction picture indicated the behavioral reaction to be performed and the reinforcer to be obtained after a subsequent trigger stimulus. Movements varied according to the reinforcers predicted by the instructions, suggesting that animals differentially expected the two outcomes. bout 250 of nearly 1,500 neurons in anterior parts of caudate nucleus, putamen, and ventral striatum showed typical task-related activations that reflected the expectation of instructions and trigger, and the preparation, initiation, and execution of behavioral reactions. Strikingly, most task-related activations occurred only when liquid reward was delivered at trial end, rather than the reinforcing sound. Activations close to the time of reward showed similar preferences for Liquid reward over the reinforcing sound, suggesting a relationship to the expectation or detection of the motivational outcome of the trial rather than to a "correct" or ''end-of-trial'' signal. By contrast, relatively few activations in the present task occurred irrespective of the type of reinforcement. In conclusion, many of the behavior-related neurons investigated in the anterior striatum were influenced by an upcoming primary liquid reward and did not appear to code behavioral acts in a motivationally neutral manner. Rather, these neurons incorporated information about the expected outcome into their behavior-related activity. The activations influenced by reward several seconds before its occurrence may constitute a neuronal basis for the retrograde effects of rewards on behavioral reactions.