Gordon A M, Lee J H, Flament D, Ugurbil K, Ebner T J
Department of Biobehavioral Sciences, Teachers College, Columbia University, New York, NY 10027, USA.
Exp Brain Res. 1998 Jul;121(2):153-66. doi: 10.1007/s002210050447.
We investigated the activation of sensory and motor areas involved in the production of typing movements using functional magnetic resonance imaging (fMRI). Eleven experienced typists performed tasks, in which the spatial and temporal requirements as well as the number of digits involved were varied. These included a simple uni-digit repetitive task, a uni-digit sequential task, a dual-digit sequential task, a multi-digit sequential task, and typing text from memory. We found that the production of simple repetitive keypresses with the index finger primarily involved the activation of contralateral primary motor cortex (M1), although a small activation of the supplementary motor area (SMA) and other regions was sometimes observed as well. The sequencing of keypresses involved bilateral M1 and a stronger activation of the SMA and to a lesser extent the premotor area, cingulate gyrus, caudate, and lentiform nuclei. However, the activation of these areas did not exclusively depend on the complexity of the movements, since they were often activated during more simple movements, such as alternating two keypresses repeatedly. Somatosensory and parietal regions were also found to be activated during typing sequences. The activation of parietal areas did not exclusively depend on the spatial requirements of the task, since similar activation was observed during movements within intra-personal space (finger-thumb opposition) and may instead be related to the temporal requirements of the task. Our findings suggest that the assembly of well-learned, goal-directed finger movement sequences involves the SMA and other secondary motor areas as well as somatosensory and parietal areas.
我们使用功能磁共振成像（fMRI）研究了与打字动作产生相关的感觉和运动区域的激活情况。11名经验丰富的打字员执行了任务，其中空间和时间要求以及涉及的手指数量各不相同。这些任务包括简单的单指重复任务、单指顺序任务、双指顺序任务、多指顺序任务以及凭记忆打字。我们发现，用食指进行简单的重复按键主要涉及对侧初级运动皮层（M1）的激活，不过有时也会观察到辅助运动区（SMA）和其他区域有少量激活。按键的顺序排列涉及双侧M1以及SMA更强的激活，前运动区、扣带回、尾状核和豆状核的激活程度较低。然而，这些区域的激活并不完全取决于动作的复杂性，因为在更简单的动作（如反复交替按下两个按键）过程中它们也经常被激活。在打字序列过程中还发现体感区和顶叶区域被激活。顶叶区域的激活并不完全取决于任务的空间要求，因为在个人空间内的动作（手指与拇指对捏）过程中也观察到了类似的激活，可能反而与任务的时间要求有关。我们的研究结果表明，熟练掌握的、目标导向的手指运动序列的组合涉及SMA和其他二级运动区域以及体感区和顶叶区域。
