Istituto Italiano di Tecnologia (IIT), Brain Center for Social and Motor Cognition (BCSMC), Via Volturno 39, 43125, Parma, Italy.
Dipartimento di Neuroscienze, Università di Parma, Via Volturno 39, 43125, Parma, Italy.
Sci Rep. 2017 Aug 15;7(1):8231. doi: 10.1038/s41598-017-08956-1.
The spatial location and viewpoint of observed actions are closely linked in natural social settings. For example, actions observed from a subjective viewpoint necessarily occur within the observer's peripersonal space. Neurophysiological studies have shown that mirror neurons (MNs) of the monkey ventral premotor area F5 can code the spatial location of live observed actions. Furthermore, F5 MN discharge can also be modulated by the viewpoint from which filmed actions are seen. Nonetheless, whether and to what extent MNs can integrate viewpoint and spatial location of live observed actions remains unknown. We addressed this issue by comparing the activity of 148 F5 MNs while macaque monkeys observed an experimenter grasping in three different combinations of viewpoint and spatial location, namely, lateral view in the (1) extrapersonal and (2) peripersonal space and (3) subjective view in the peripersonal space. We found that the majority of MNs were space-selective (60.8%): those selective for the peripersonal space exhibited a preference for the subjective viewpoint both at the single-neuron and population level, whereas space-unselective neurons were view invariant. These findings reveal the existence of a previously neglected link between spatial and viewpoint selectivity in MN activity during live-action observation.
在自然社会环境中，观察到的动作的空间位置和视角密切相关。例如，从主观视角观察到的动作必然发生在观察者的个人空间内。神经生理学研究表明，猴子腹侧前运动区 F5 的镜像神经元 (MNs) 可以对活体观察到的动作的空间位置进行编码。此外，F5MN 的放电也可以通过观察到的动作的视角进行调节。然而，MN 是否以及在多大程度上可以整合活体观察到的动作的视角和空间位置仍然未知。我们通过比较 148 个 F5MN 在猕猴观察实验者以三种不同的视角和空间位置组合进行抓取时的活动来解决这个问题，即（1）体外和（2）个人空间以及（3）个人空间中的主观视角。我们发现，大多数 MN 是空间选择性的（60.8%）：那些对个人空间有选择性的 MN 在单神经元和群体水平上都更喜欢主观视角，而空间非选择性神经元则与视角无关。这些发现揭示了在活体动作观察过程中 MN 活动的空间和视角选择性之间存在一个以前被忽视的联系。
