Ehrsson H Henrik, Geyer Stefan, Naito Eiichi
Department of Neuroscience and Motor Control Laboratory, Karolinska Institutet, S-17176 Stockholm, Sweden.
J Neurophysiol. 2003 Nov;90(5):3304-16. doi: 10.1152/jn.01113.2002.
We investigate whether imagery of voluntary movements of different body parts activates somatotopical sections of the human motor cortices. We used functional magnetic resonance imaging to detect the cortical activity when 7 healthy subjects imagine performing repetitive (0.5-Hz) flexion/extension movements of the right fingers or right toes, or horizontal movements of the tongue. We also collected functional images when the subjects actually executed these movements and used these data to define somatotopical representations in the motor areas. In this study, we relate the functional activation maps to cytoarchitectural population maps of areas 4a, 4p, and 6 in the same standard anatomical space. The important novel findings are 1). that imagery of hand movements specifically activates the hand sections of the contralateral primary motor cortex (area 4a) and the contralateral dorsal premotor cortex (area 6) and a hand representation located in the caudal cingulate motor area and the most ventral part of the supplementary motor area; 2). that when imagining making foot movements, the foot zones of the posterior part of the contralateral supplementary motor area (area 6) and the contralateral primary motor cortex (area 4a) are active; and 3). that imagery of tongue movements activates the tongue region of the primary motor cortex and the premotor cortex bilaterally (areas 4a, 4p, and 6). These results demonstrate that imagery of action engages the somatotopically organized sections of the primary motor cortex in a systematic manner as well as activating some body-part-specific representations in the nonprimary motor areas. Thus the content of the mental motor image, in this case the body part, is reflected in the pattern of motor cortical activation.
我们研究了不同身体部位的自主运动意象是否会激活人类运动皮层的躯体感觉区。我们使用功能磁共振成像来检测7名健康受试者想象进行右手手指或右脚趾的重复性（0.5赫兹）屈伸运动，或舌头的水平运动时的皮层活动。我们还收集了受试者实际执行这些运动时的功能图像，并使用这些数据来定义运动区域中的躯体感觉表征。在本研究中，我们将功能激活图与相同标准解剖空间中4a、4p和6区的细胞构筑群体图相关联。重要的新发现是：1）手部运动意象特异性地激活对侧初级运动皮层（4a区）的手部区域、对侧背侧运动前区皮层（6区）以及位于尾侧扣带运动区和辅助运动区最腹侧部分的手部表征；2）当想象进行足部运动时，对侧辅助运动区后部（6区）和对侧初级运动皮层（4a区）的足部区域会被激活；3）舌头运动意象会双侧激活初级运动皮层和运动前区皮层的舌区（4a、4p和6区）。这些结果表明，动作意象以系统的方式激活了初级运动皮层的躯体感觉组织区域，同时也激活了非初级运动区域中一些特定身体部位的表征。因此，在这种情况下，心理运动图像的内容，即身体部位，反映在运动皮层激活模式中。
