Imamizu Hiroshi, Kuroda Tomoe, Miyauchi Satoru, Yoshioka Toshinori, Kawato Mitsuo
Advanced Telecommunications Research Institute, Human Information Science Laboratories, 2-2-2 Hikaridai, Seika, Soraku, Kyoto 619-0288, Japan.
Proc Natl Acad Sci U S A. 2003 Apr 29;100(9):5461-6. doi: 10.1073/pnas.0835746100. Epub 2003 Apr 18.
Human capabilities in manipulating many different tools with dexterity suggest modular neural organization at functional levels, but anatomical modularity underlying the capabilities has yet to be demonstrated. Although modularity in phylogenetically older parts of the cerebellum is well known, comparable modularity in the lateral cerebellum for cognitive functions remains unknown. We investigated these issues by functional MRI (fMRI) based on our previous findings of a cerebellar internal model of a tool. After subjects intensively learned to manipulate two novel tools (the rotated mouse whose cursor appeared at a rotated position, and the velocity mouse whose cursor velocity was proportional to the mouse position), they could easily switch between the two. The lateral and posterior cerebellar activities for the two different tools were spatially segregated, and their overlaps were <10%, even at low statistical thresholds. Activities of the rotated mouse were more anterior and lateral than the velocity mouse activities. These results were consistent with predictions by the MOdular Selection And Identification Controller (MOSAIC) model that multiple internal models compete to partition sensory-motor experiences and their outputs are linearly combined for a particular context.
人类灵活操作多种不同工具的能力表明在功能层面存在模块化神经组织，但这种能力背后的解剖学模块化尚未得到证实。尽管小脑在系统发育上较古老部分的模块化是众所周知的，但小脑外侧用于认知功能的类似模块化仍然未知。基于我们之前关于工具的小脑内部模型的发现，我们通过功能磁共振成像（fMRI）对这些问题进行了研究。在受试者深入学习操作两种新型工具（光标出现在旋转位置的旋转鼠标，以及光标速度与鼠标位置成比例的速度鼠标）之后，他们能够轻松地在两者之间切换。两种不同工具在小脑外侧和后部的活动在空间上是分离的，即使在低统计阈值下，它们的重叠也小于10%。旋转鼠标的活动比速度鼠标的活动更靠前和靠外侧。这些结果与模块化选择与识别控制器（MOSAIC）模型的预测一致，即多个内部模型竞争以划分感觉运动体验，并且它们的输出在特定情境下进行线性组合。
