Higuchi Satomi, Imamizu Hiroshi, Kawato Mitsuo
Graduate School of Information Science, Nara Institute of Science and Technology, Nara, Japan.
Cortex. 2007 Apr;43(3):350-8. doi: 10.1016/s0010-9452(08)70460-x.
The purpose of this study is to identify the functional brain networks activated in relation to actual tool-use in humans. Although previous studies have identified brain activity related to tool-use gestures (Moll et al., 2000), they did not investigate the brain activity involved in such tool-use. We investigated brain activity using functional magnetic resonance imaging (fMRI) while human subjects mentally imagined using sixteen common tools and while they actually used them. Brain activity for both actual and imagined tool-use was found in the posterior part of the parietal cortex, in the supplementary motor area, and in the cerebellum. Under imagined tool-use conditions, we found brain activity in the premotor and right pars opercularis. Under actual tool-use conditions, we found it in the primary motor area, in the thalamus, and in the left pars opercularis. Our precise analysis in the cerebellum indicated that activity evoked by imagery was located significantly more lateral to that evoked by actual use. We found a relationship between activity in the tool imagery and execution conditions by comparing their t-value-weighted centroid of activation coordinates. Moreover, for half of the subjects the spatial distribution pattern for each tool was similar, suggesting that neural mechanisms contributing to skillful tool-use are modularly organized in the cerebellum.
本研究的目的是确定与人类实际工具使用相关的功能性脑网络。尽管先前的研究已经确定了与工具使用手势相关的脑活动（莫尔等人，2000年），但他们并未研究此类工具使用中涉及的脑活动。我们使用功能磁共振成像（fMRI）对人类受试者在心理想象使用16种常见工具以及实际使用这些工具时的脑活动进行了研究。在实际和想象工具使用时，均在顶叶皮质后部、辅助运动区和小脑中发现了脑活动。在想象工具使用条件下，我们在前运动区和右侧 opercularis 部发现了脑活动。在实际工具使用条件下，我们在初级运动区、丘脑和左侧 opercularis 部发现了脑活动。我们在小脑中的精确分析表明，由想象诱发的活动在位置上比由实际使用诱发的活动更偏外侧。通过比较工具想象和执行条件下激活坐标的 t 值加权质心，我们发现了它们之间的活动关系。此外，对于一半的受试者，每种工具的空间分布模式相似，这表明有助于熟练工具使用的神经机制在小脑中呈模块化组织。
