School of Sport and Exercise Sciences, University of Birmingham, England B15 2TT, UK.
Brain Res. 2009 Dec 22;1304:57-65. doi: 10.1016/j.brainres.2009.09.092. Epub 2009 Sep 30.
This work investigated human brain activity in healthy subjects during an involuntary movement. The involuntary movement was driven by an involuntary postural aftercontraction of the deltoid muscle of the shoulder which follows the cessation of a prolonged isometric voluntary contraction. Previous authors have suggested that this aftercontraction phenomenon does not involve the cerebral cortex. To test this idea we examined brain activation using functional magnetic resonance imaging (fMRI) during the involuntary movement and during a matched voluntary movement. In contrast to the conjectures of earlier authors, during the involuntary movement there was widespread activation of the cerebral cortex. There were also clear activation differences between conditions. The voluntary movement showed activation of the putamen whereas the involuntary movement showed much greater activation of the anterior cingulate cortex (BA 24/32). There were also some similarities in the brain areas activated under both movement conditions namely in the left hemisphere precentral gyrus (BA 4), the left hemisphere superior parietal lobe (BA 7), and the bilateral superior temporal gyrus (BA 22). Activity was also present in the caudate nucleus, the thalamus, and the cerebellum. The results are discussed in relation to theories of aftercontraction generation and error processing by the anterior cingulate.
本研究旨在探讨健康受试者在无意识运动时的大脑活动。无意识运动是由三角肌的无意识姿势后收缩引起的，这种收缩发生在长时间等长自主收缩停止之后。先前的作者认为，这种后收缩现象不涉及大脑皮层。为了验证这一观点，我们使用功能磁共振成像（fMRI）在无意识运动和匹配的自主运动时检查大脑激活。与早期作者的推测相反，在无意识运动时大脑皮层广泛激活。两种运动条件之间也存在明显的激活差异。自主运动表现出壳核的激活，而无意识运动则表现出更大的前扣带皮层（BA24/32）的激活。两种运动条件下激活的大脑区域也有一些相似之处，即左半球中央前回（BA4）、左半球顶叶上回（BA7）和双侧颞上回（BA22）。尾状核、丘脑和小脑也有活动。结果与前扣带对后收缩产生和错误处理的理论进行了讨论。
