Thompson R F, Thompson J K, Kim J J, Krupa D J, Shinkman P G
Program in Neuroscience, University of Southern California, 3614 Watt Way, Los Angeles, California 90089-2520, USA.
Neurobiol Learn Mem. 1998 Jul-Sep;70(1-2):150-76. doi: 10.1006/nlme.1998.3845.
In a now classic study, W. J. Brogden and W. H. Gantt (1942, American Journal of Physiology, 119, 277-278) demonstrated that movements (limbs, head, eyelid) elicited by direct electrical stimulation of certain regions of the cerebellum (particularly the ansiform lobe) could be trained to respond to neutral auditory or visual conditioned stimuli with appropriate pairing. In recent work we have replicated these results in detail and presented considerable evidence that the reinforcing or "teaching" pathway so activated for the learning of discrete movements is the inferior olive-climbing fiber projection system to the cerebellum. Very strong evidence now indicates that the memory traces for this "skilled response" learning are formed and stored in the cerebellum. The climbing fiber system and inhibitory pathway from the interpositus nucleus to the inferior olive appear to form a neural instantiation of the Resorla-Wagner formulation of classical conditioning and accounts for the "cognitive" phenomenon of blocking. It is concluded that reinforcement in this form of learning is not due simply to contiguity/contingency or to unconditioned stimulus aversiveness, per se, but rather to activation of a particular brain circuit, here the climbing fiber system, a circumstance that may apply to other forms of learning, with other reinforcement circuits, as well.
在一项如今堪称经典的研究中，W. J. 布罗格登和W. H. 甘特（1942年，《美国生理学杂志》，第119卷，第277 - 278页）证明，通过直接电刺激小脑的某些区域（特别是半月叶）引发的运动（肢体、头部、眼睑），可以通过适当配对训练使其对中性听觉或视觉条件刺激做出反应。在最近的研究中，我们详细重复了这些结果，并提供了大量证据表明，为学习离散运动而如此激活的强化或“教导”通路是小脑的下橄榄核 - 攀缘纤维投射系统。现在有非常确凿的证据表明，这种“熟练反应”学习的记忆痕迹在小脑中形成并存储。攀缘纤维系统以及从间位核到下橄榄核的抑制性通路似乎构成了经典条件作用的雷索尔拉 - 瓦格纳公式的神经实例，并解释了“阻塞”这一“认知”现象。得出的结论是，这种学习形式中的强化并非仅仅归因于邻近性/偶然性，也不是无条件刺激的厌恶性质本身，而是特定脑回路（此处为攀缘纤维系统）的激活，这种情况可能也适用于其他形式的学习以及其他强化回路。
