Cognitive Neuroscience Sector, SISSA Trieste, Italy.
Neuroimage. 2012 Jan 16;59(2):1622-30. doi: 10.1016/j.neuroimage.2011.09.004. Epub 2011 Sep 10.
Human ability to imitate movements is instantiated in parietal, premotor and opercular structures, often referred to as the human homologue of the macaque mirror neuron system. As most studies employed imitation of specular models (participants imitated the seen movement as their mirror reflection), it is unclear whether the structures implicated code for the anatomical compatibility between the performer and the model or the spatial compatibility between the location at which both movements occur. We used fMRI to disentangle the neural mechanisms underlying anatomical and spatial components of imitation. Participants moved one finger which was either spatially or anatomically compatible with the finger moved in a video-display. In keeping with the existent behavioral literature, we found that during the spatial task, participants' responses were faster when the seen movement was also anatomically compatible, whereas in the anatomical task, responses were faster when the seen movement was also spatially compatible. Critically, the activity of the parietal opercula bilaterally was associated with the anatomical compatibility effect. Furthermore, increased activity of the left middle frontal gyrus and right superior temporal sulcus (extending to the temporo-parietal junction) was found in those trials in which the spatial mapping between the seen and executed movements was detrimental for the anatomical task. Our findings extend current understanding of the role played by spatial and anatomical components in imitation and provide new insights about the parietal opercula.
人类模仿动作的能力体现在顶叶、前运动和脑岛结构中，这些结构通常被称为猕猴镜像神经元系统的人类同源物。由于大多数研究采用镜像模型的模仿（参与者模仿所看到的运动作为其镜像反射），因此尚不清楚所涉及的结构是否编码执行者和模型之间的解剖兼容性或两个运动发生的位置之间的空间兼容性。我们使用 fMRI 来区分模仿的解剖和空间成分的神经机制。参与者移动一个手指，该手指在视频显示中与所移动的手指在空间上或解剖上兼容。与现有的行为文献一致，我们发现，在空间任务中，当看到的运动也在解剖上兼容时，参与者的反应更快，而在解剖任务中，当看到的运动也在空间上兼容时，反应更快。关键的是，双侧顶叶脑岛的活动与解剖兼容性效应有关。此外，在那些对执行动作的空间映射对解剖任务不利的试验中，发现左额中回和右颞上回（延伸至颞顶联合区）的活动增加。我们的发现扩展了对模仿中空间和解剖成分所起作用的现有理解，并提供了关于顶叶脑岛的新见解。
