Choi S H, Na D L, Kang E, Lee K M, Lee S W, Na D G
Department of Neurology, College of Medicine, Inha University, Incheon, Korea.
Exp Brain Res. 2001 Aug;139(3):311-7. doi: 10.1007/s002210100777.
The purpose of this study was to identify the functional fields activated in relation to gestural movements. Using functional magnetic resonance imaging (fMRI), we mapped brain activity in ten right-handed, normal volunteers during activation and control tasks. The activation condition consisted of pantomiming tool-use gestures with either the left hand or right hand, whereas the control condition comprised repetitive, oppositional movements between thumb and index finger. Activated cortical regions were highly lateralized to the left hemisphere during pantomiming of tool use regardless of hand used. Praxis with either hand commonly activated the superior parietal lobule, supplementary motor area, premotor area of the left hemisphere, and cerebellar vermis. However, minimal activation occurred in the inferior parietal lobule, which has been known to be a critical area for praxis generation. Compared with left-hand praxis, right-hand praxis exhibited additional activation in the left putamen and posterior part of the left inferior temporal region. Our findings concur with neuropsychological observations that the left hemisphere in right-handers mediates programming and executing skilled movements and that, within the left hemisphere, praxis is predominantly subserved by the parietal lobe, supplementary motor area, and premotor area. However, unlike previous lesion studies, the results of our fMRI study suggested that the superior parietal lobule more likely than the inferior parietal lobule play an important role in gesture production.
本研究的目的是确定与手势动作相关的激活功能区。我们使用功能磁共振成像（fMRI）技术，在激活任务和对照任务期间，对10名右利手正常志愿者的大脑活动进行了图谱绘制。激活条件包括用左手或右手模仿使用工具的手势，而对照条件包括拇指和食指之间的重复性反向运动。在使用工具的模仿动作中，无论使用哪只手，激活的皮质区域都高度定位于左半球。使用任何一只手进行的运用动作通常会激活顶上小叶、辅助运动区、左半球的运动前区和小脑蚓部。然而，在已知是运用动作产生关键区域的顶下小叶中，激活程度极小。与左手运用动作相比，右手运用动作在左侧壳核和左侧颞下回后部表现出额外的激活。我们的研究结果与神经心理学观察结果一致，即右利手者的左半球介导熟练动作的编程和执行，并且在左半球内，运用动作主要由顶叶、辅助运动区和运动前区提供支持。然而，与先前的病变研究不同，我们的fMRI研究结果表明，顶上小叶比顶下小叶更有可能在手势产生中发挥重要作用。
