Cusack William F, Cope Michael, Nathanson Sheryl, Pirouz Nikta, Kistenberg Robert, Wheaton Lewis A
School of Applied Physiology, Georgia Institute of Technology, Atlanta GA, USA.
Front Hum Neurosci. 2012 Jun 29;6:182. doi: 10.3389/fnhum.2012.00182. eCollection 2012.
The mirror neuron system (MNS) has been attributed with increased activation in motor-related cortical areas upon viewing of another's actions. Recent work suggests that limb movements that are similar and dissimilar in appearance to that of the viewer equivalently activate the MNS. It is unclear if this result can be observed in the action encoding areas in amputees who use prosthetic devices. Intact subjects and upper extremity amputee prosthesis users were recruited to view video demonstrations of tools being used by an intact actor and a prosthetic device user. All subjects pantomimed the movements seen in the video while recording electroencephalography (EEG). Intact subjects showed equivalent left parietofrontal activity during imitation planning after watching the intact or prosthetic arm. Likewise, when prosthesis users imitated prosthesis demonstrations, typical left parietofrontal activation was observed. When prosthesis users imitated intact actors, an additional pattern was revealed which showed greater activity in right parietal and occipital regions that are associated with the mentalizing system. This change may be required for prosthesis users to plan imitation movements in which the limb states between the observed and the observer do not match. The finding that prosthesis users imitating other prosthesis users showed typical left parietofrontal activation suggests that these subjects engage normal planning related activity when they are able to imitate a limb matching their own. This result has significant implications on rehabilitation, as standard therapy involves training with an intact occupational therapist, which could necessitate atypical planning mechanisms in amputees when learning to use their prosthesis.
镜像神经元系统（MNS）被认为在观察他人动作时，与动作相关的皮质区域会有增强的激活。最近的研究表明，与观察者外观相似和不同的肢体动作会同等程度地激活MNS。目前尚不清楚在使用假肢的截肢者的动作编码区域是否能观察到这一结果。招募了健全受试者和上肢截肢假肢使用者，让他们观看健全演员和假肢使用者使用工具的视频演示。所有受试者在模仿视频中看到的动作时记录脑电图（EEG）。健全受试者在观看健全或假肢手臂后进行模仿计划时，左侧顶叶额叶活动相当。同样，当假肢使用者模仿假肢演示时，观察到典型的左侧顶叶额叶激活。当假肢使用者模仿健全演员时，发现了另一种模式，即与心理化系统相关的右侧顶叶和枕叶区域有更大的活动。对于假肢使用者来说，计划观察到的肢体状态与观察者的肢体状态不匹配的模仿动作时，可能需要这种变化。假肢使用者模仿其他假肢使用者时出现典型的左侧顶叶额叶激活这一发现表明，当这些受试者能够模仿与自己肢体匹配的动作时，他们参与了正常的计划相关活动。这一结果对康复具有重要意义，因为标准治疗包括与健全的职业治疗师一起训练，这可能会使截肢者在学习使用假肢时需要非典型的计划机制。
