Minimizing errors is an important aspect of learning. However, it is not enough merely to record if an error occurred. For efficient learning, information about the magnitude of errors is critical. Did my tennis swing completely miss the target or did I hit the ball, but not quite in the sweet spot? How can neurons – which have traditionally been thought of as binary units – signal the magnitude of an error? Here I review evidence that eyeblink conditioning – a basic form of motor learning – depends on graded signals from the inferior olive which guides plasticity in the cerebellum and ultimately tunes behavior. Specifically, evidence suggests that: (1) Error signals are conveyed to the cerebellum via the inferior olive; (2) Signals from the inferior olive are graded; (3) The strength of the olivary signal affects learning; (4) Cerebellar feedback influences the strength of the olivary signal. I end the review by exploring how graded error signals might explain some behavioral learning phenomena.

减少错误是学习的重要方面。但是，仅记录是否发生错误是不够的。为了有效学习，有关错误幅度的信息至关重要。我的网球挥杆是否完全没有击中目标，还是我击中了球，但并没有达到最佳位置？神经元-传统上被认为是二进制单位的神经元-如何能发出错误的幅度信号？在这里，我回顾了证据，即眨眼调节（一种运动学习的基本形式）取决于来自下橄榄的分级信号，该信号指导小脑的可塑性并最终调节行为。具体而言，证据表明：（1）错误信号通过下橄榄传递到小脑；（2）来自下橄榄的信号被分级；（3）橄榄信号的强度影响学习；（4）小脑反馈影响橄榄信号的强度。我通过探讨分级错误信号如何解释某些行为学习现象来结束本评论。