Motor Control Laboratory, Research Center for Movement Control and Neuroplasticity, Group Biomedical Sciences, KU Leuven, Leuven 3000, Belgium.
Learn Mem. 2012 Jul 26;19(8):351-7. doi: 10.1101/lm.026534.112.
The corpus callosum (CC) is the largest white matter tract in the brain. It enables interhemispheric communication, particularly with respect to bimanual coordination. Here, we use diffusion tensor imaging (DTI) in healthy humans to determine the extent to which structural organization of subregions within the CC would predict how well subjects learn a novel bimanual task. A single DTI scan was taken prior to training. Participants then practiced a bimanual visuomotor task over the course of 2 wk, consisting of multiple coordination patterns. Findings revealed that the predictive power of fractional anisotropy (FA) was a function of CC subregion and practice. That is, FA of the anterior CC, which projects to the prefrontal cortex, predicted bimanual learning rather than the middle CC regions, which connect primary motor cortex. This correlation was specific in that FA correlated significantly with performance of the most difficult frequency ratios tested and not the innately preferred, isochronous frequency ratio. Moreover, the effect was only evident after training and not at initiation of practice. This is the first DTI study in healthy adults which demonstrates that white matter organization of the interhemispheric connections between the prefrontal structures is strongly correlated with motor learning capability.
胼胝体（CC）是大脑中最大的白质束。它使大脑两半球之间能够进行交流，特别是在双手协调方面。在这里，我们使用健康人类的弥散张量成像（DTI）来确定 CC 内各亚区的结构组织在多大程度上可以预测受试者学习新的双手任务的能力。在训练之前进行了单次 DTI 扫描。然后，参与者在 2 周的时间内练习双手视觉运动任务，包括多种协调模式。研究结果表明，各向异性分数（FA）的预测能力是 CC 亚区和练习的函数。也就是说，连接前额叶皮层的前胼胝体的 FA 预测了双手学习能力，而不是连接初级运动皮层的中间 CC 区域。这种相关性是特异性的，因为 FA 与测试的最困难频率比的表现显著相关，而不是天生的等时频率比。此外，这种效应仅在训练后而不是在练习开始时显现。这是首次在健康成年人中进行的 DTI 研究，证明了前额叶结构之间的半球间连接的白质组织与运动学习能力密切相关。
