Gazzola Valeria, van der Worp Henk, Mulder Theo, Wicker Bruno, Rizzolatti Giacomo, Keysers Christian
BCN Neuroimaging Center, University Medical Center Groningen, University of Groningen, A. Deusinglaan 2, 9713 AW Groningen, The Netherlands.
Curr Biol. 2007 Jul 17;17(14):1235-40. doi: 10.1016/j.cub.2007.06.045.
The premotor and parietal mirror neuron system (MNS) is thought to contribute to the understanding of observed actions by mapping them onto "corresponding" motor programs of the observer [1-24], but how would the MNS respond to the observation of hand actions if the observer never had hands? Would it not show changes of blood-oxygen-level dependent (BOLD) signal, because the observer lacks motor programs that can resonate [12, 25, 26], or would it show significant changes because the observer has motor programs for the foot or mouth with corresponding goals [15, 17, 19, 27, 28]? We scanned two aplasic subjects, born without arms or hands, while they watched hand actions and compared their brain activity with that of 16 control subjects. All subjects additionally executed actions with different effectors (feet, mouth, and, for controls, hands). The BOLD signal of aplasic individuals within the putative MNS was augmented when they watched hand actions, demonstrating the brain's capacity to mirror actions that deviate from the embodiment of the observer by recruiting voxels involved in the execution of actions that achieve corresponding goals by different effectors. This sheds light on the functional organization of the MNS and predominance of goals in imitation.
运动前区和顶叶镜像神经元系统（MNS）被认为通过将观察到的动作映射到观察者的“相应”运动程序来促进对这些动作的理解[1-24]，但如果观察者从未有过双手，MNS会如何对观察到手部动作做出反应呢？它不会因为观察者缺乏能够产生共鸣的运动程序而不显示血氧水平依赖（BOLD）信号的变化[12, 25, 26]，还是会因为观察者有针对足部或口腔且具有相应目标的运动程序而显示出显著变化呢[15, 17, 19, 27, 28]？我们对两名先天性无手臂或双手的发育不全受试者进行了扫描，观察他们观看手部动作时的情况，并将他们的大脑活动与16名对照受试者的大脑活动进行比较。所有受试者还使用不同的效应器（足部、口腔，对照受试者使用手部）执行动作。发育不全个体在假定的MNS内的BOLD信号在观看手部动作时增强，这表明大脑能够通过募集参与使用不同效应器实现相应目标的动作执行的体素，来镜像与观察者身体表现不同的动作。这为MNS的功能组织以及模仿中目标的主导地位提供了线索。
