Brain Behav. 2012 May;2(3):237-42. doi: 10.1002/brb3.50.
Mirror neurons are recognized as a crucial aspect of motor and social learning yet we know little about their origins and development. Two competing hypotheses are highlighted in the literature. One suggests that mirror neurons may be innate and are an adaptation for action understanding. The alternative, proposes that mirror neurons develop through sensorimotor experience. To date, there has been little direct evidence from infant studies to support either argument. In the present study, we explored the temporal dynamics and spatial distribution of electroencephalography (EEG) brain responses in young infants during the observation of three distinct types of actions: (a) actions that are within the motor repertoire of infants, (b) actions that are not within the motor repertoire of infants, and (c) object motion. We show that young infants had significant motor resonance to all types of actions in the sensorimotor regions. Only observation of human goal-directed actions led to significant responses in the parietal regions. Importantly, there was no significant mu desychronization observed in the temporal regions under any observation condition. In addition, the onset of mu desychronization occurred earliest in response to object motion, followed by reaching, and finally walking. Our results suggest that the infants may have a basic, experience-independent sensorimotor mechanism optimized to detect all coherent motion that is modulated by experience.
镜像神经元被认为是运动和社会学习的关键方面，但我们对它们的起源和发展知之甚少。文献中突出了两种相互竞争的假说。一种假设认为镜像神经元可能是先天的，是对动作理解的一种适应。另一种假设则提出，镜像神经元通过感觉运动经验发展而来。迄今为止，婴儿研究几乎没有直接证据支持这两种观点。在本研究中，我们通过对三种不同类型的动作（a）婴儿运动范围内的动作、（b）婴儿运动范围外的动作和（c）物体运动的观察，探讨了幼儿在观察过程中脑电图（EEG）大脑反应的时间动态和空间分布。我们发现，幼儿在运动感觉区域对所有类型的动作都有显著的运动共鸣。只有观察到人类有目的的动作才会引起顶叶区域的显著反应。重要的是，在任何观察条件下，在时间区域都没有观察到显著的 mu 去同步。此外，mu 去同步的出现最早是对物体运动的反应，其次是伸手，最后是行走。我们的结果表明，婴儿可能有一种基本的、无需经验的运动感觉机制，这种机制可以优化对所有由经验调制的连贯运动的检测。
