Papadourakis Vassilis, Raos Vassilis
Department of Basic Sciences, Faculty of Medicine, School of Health Sciences, University of Crete and Computational Neuroscience Group, Institute of Applied and Computational Mathematics, Foundation for Research and Technology-Hellas, Heraklion, Greece.
Department of Basic Sciences, Faculty of Medicine, School of Health Sciences, University of Crete and Computational Neuroscience Group, Institute of Applied and Computational Mathematics, Foundation for Research and Technology-Hellas, Heraklion, Greece
J Neurophysiol. 2017 Dec 1;118(6):3215-3229. doi: 10.1152/jn.00816.2016. Epub 2017 Sep 20.
Mirror neurons (MirNs) are sensorimotor neurons that fire both when an animal performs a goal-directed action and when the same animal observes another agent performing the same or a similar transitive action. It has been claimed that the observation of intransitive actions does not activate MirNs in a monkey's brain. Prompted by recent evidence indicating that the discharge of MirNs is modulated also by non-object-directed actions, we investigated thoroughly the efficacy of intransitive actions to trigger MirNs' discharge. Using representational similarity analysis, we also studied whether the elements constituting the visual scene presented to the monkey during the observation of actions (both transitive and intransitive) are represented in the discharge of MirNs. For this purpose, the moving hand was modeled by its kinematics and the object by features of its geometry. We found that MirNs respond to the observation of both transitive and intransitive actions and that the discharge differences evoked by the observation of object- and non-object-directed actions are correlated more with the kinematic differences of these actions than with the differences of the objects' features. These findings support the view that observed action kinematics contribute to action mirroring. Mirror neurons in the monkey brain are thought to respond exclusively to the observation of object-directed actions. Here, we show that mirror neurons also respond to the observation of intransitive actions and that the kinematics of the observed movements are represented in their discharge. This finding supports the view that mirror neurons provide also a kinematics-based representation of actions.
镜像神经元（MirNs）是一种感觉运动神经元，当动物执行目标导向动作时以及当同一动物观察到另一个体执行相同或类似的及物动作时，它们都会放电。有人声称，观察不及物动作不会激活猴子大脑中的镜像神经元。鉴于最近有证据表明镜像神经元的放电也受到非目标导向动作的调节，我们深入研究了不及物动作触发镜像神经元放电的效能。使用表征相似性分析，我们还研究了在观察动作（及物和不及物）期间呈现给猴子的视觉场景的构成元素是否在镜像神经元的放电中得到表征。为此，通过运动学对手部运动进行建模，并通过几何特征对物体进行建模。我们发现，镜像神经元对及物和不及物动作的观察均有反应，并且观察目标导向和非目标导向动作所引发的放电差异，与这些动作的运动学差异的相关性，比与物体特征差异的相关性更大。这些发现支持了这样一种观点，即观察到的动作运动学有助于动作镜像。猴子大脑中的镜像神经元被认为仅对目标导向动作的观察有反应。在这里，我们表明镜像神经元也对不及物动作的观察有反应，并且观察到的运动的运动学在它们的放电中得到表征。这一发现支持了这样一种观点，即镜像神经元也提供基于运动学的动作表征。
