Ferrari P F, Bonini L, Fogassi L
Dipartimento di Biologia Evolutiva e Funzionale, via Usberti 11/a, Universitá di Parma, 43100, Parma, Italy.
Philos Trans R Soc Lond B Biol Sci. 2009 Aug 27;364(1528):2311-23. doi: 10.1098/rstb.2009.0062.
The discovery of mirror neurons (MNs), deemed to be at the basis of action understanding, could constitute the potential solution to the 'correspondence problem' between one's own and others' action that is crucial for of imitative behaviours. However, it is still to be clarified whether, and how, several imitative phenomena, differing in terms of complexity and cognitive effort, could be explained within a unified framework based on MNs. Here we propose that MNs could differently contribute to distinct imitative behaviours by means of two anatomo-functional pathways, subjected to changes during development. A 'direct mirror pathway', directly influencing the descending motor output, would be responsible for neonatal and automatic imitation. This proposal is corroborated by some new behavioural evidences provided here. During development, the increased control of voluntary movements and the capacity to efficiently suppress automatic motor activation during action observation assign to the core MNs regions essentially perceptuo-cognitive functions. These functions would be exploited by an 'indirect mirror pathway' from the core regions of the MN system to prefrontal cortex. This latter would play a key role in parsing, storing and organizing motor representations, allowing the emergence of more efficient and complex imitative behaviours such as response facilitation and true imitation.
镜像神经元（MNs）的发现被认为是动作理解的基础，它可能为自身与他人动作之间的“对应问题”提供潜在解决方案，而这一问题对于模仿行为至关重要。然而，在基于MNs的统一框架内，能否以及如何解释几种在复杂性和认知努力方面存在差异的模仿现象，仍有待阐明。在此，我们提出MNs可通过两条在发育过程中会发生变化的解剖功能路径，对不同的模仿行为产生不同的作用。一条“直接镜像路径”直接影响下行运动输出，负责新生儿和自动模仿。本文提供的一些新的行为证据证实了这一观点。在发育过程中，对随意运动的控制增强以及在动作观察期间有效抑制自动运动激活的能力，使MNs的核心区域主要承担感知认知功能。这些功能将被从MN系统核心区域到前额叶皮层的“间接镜像路径”所利用。后者在解析、存储和组织运动表征方面将发挥关键作用，从而使更高效、复杂的模仿行为得以出现，如反应促进和真正的模仿。
