Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
Elife. 2019 Oct 29;8:e46870. doi: 10.7554/eLife.46870.
Climbing fiber inputs to the cerebellum encode error signals that instruct learning. Recently, evidence has accumulated to suggest that the cerebellum is also involved in the processing of reward. To study how rewarding events are encoded, we recorded the activity of climbing fibers when monkeys were engaged in an eye movement task. At the beginning of each trial, the monkeys were cued to the size of the reward that would be delivered upon successful completion of the trial. Climbing fiber activity increased when the monkeys were presented with a cue indicating a large reward, but not a small reward. Reward size did not modulate activity at reward delivery or during eye movements. Comparison between climbing fiber and simple spike activity indicated different interactions for coding of movement and reward. These results indicate that climbing fibers encode the expected reward size and suggest a general role of the cerebellum in associative learning beyond error correction.
climbing 纤维输入到小脑编码指令学习的错误信号。最近，有证据表明小脑也参与了奖励的处理。为了研究奖励事件是如何被编码的，我们在猴子进行眼球运动任务时记录了 climbing 纤维的活动。在每次试验开始时，猴子会被提示试验成功后将获得的奖励大小。当猴子接收到表示大奖励的提示时，climbing 纤维活动增加，但接收到小奖励的提示时则没有增加。奖励大小不会调节奖励传递或眼球运动期间的活动。climbing 纤维活动和简单 spikes 活动的比较表明，运动和奖励的编码有不同的相互作用。这些结果表明 climbing 纤维编码预期的奖励大小，并表明小脑在关联学习中的一般作用超越了错误纠正。
