PDF(Pubmed)
Abstract：
Modulation of neuronal firing rates by the spatial locations of physical objects is a widespread phenomenon in the brain. However, little is known about how neuronal responses to the actions of biological entities are spatially tuned and whether such spatially tuned responses are affected by social contexts. These issues are of key importance for understanding the neural basis of embodied social cognition, such as imitation and perspective-taking. Here, we show that spatial representation of actions can be dynamically changed depending on others\' social relevance and agents of action. Monkeys performed a turn-taking choice task with a real monkey partner sitting face-to-face or a filmed partner in prerecorded videos. Three rectangular buttons (left, center, and right) were positioned in front of the subject and partner as their choice targets. We recorded from single neurons in two frontal nodes in the social brain, the ventral premotor cortex (PMv) and the medial prefrontal cortex (MPFC). When the partner was filmed rather than real, spatial preference for partner-actions was markedly diminished in MPFC, but not PMv, neurons. This social context-dependent modulation in the MPFC was also evident for self-actions. Strikingly, a subset of neurons in both areas switched their spatial preference between self-actions and partner-actions in a diametrically opposite manner. This observation suggests that these cortical areas are associated with coordinate transformation in ways consistent with an actor-centered perspective-taking coding scheme. The PMv may subserve such functions in context-independent manners, whereas the MPFC may do so primarily in social contexts.
摘要：
物理对象的空间位置对神经元放电率的调节是大脑中的普遍现象。然而,关于神经元对生物实体行为的反应是如何在空间上调节的，以及这种在空间上调节的反应是否受到社会环境的影响，人们知之甚少。这些问题对于理解具体社会认知的神经基础至关重要，比如模仿和透视。这里,我们表明，行动的空间表示可以根据他人的社会相关性和行动代理而动态变化。猴子在预先录制的视频中与一个真正的猴子伴侣面对面或拍摄的伴侣一起执行了选择任务。三个矩形按钮(左,中心,和右)被定位在受试者和伴侣的前面，作为他们的选择目标。我们记录了社交大脑两个额叶节点的单个神经元，腹侧运动前皮层（PMv）和内侧前额叶皮层（MPFC）。当搭档被拍摄而不是真实的时候，在MPFC中，对伙伴行动的空间偏好明显减弱，但不是PMv，神经元。MPFC中这种与社会背景相关的调制对于自我行为也很明显。引人注目的是，两个区域中的神经元子集以截然相反的方式在自我行为和伴侣行为之间切换了空间偏好。此观察表明，这些皮质区域以与以演员为中心的透视编码方案一致的方式与坐标变换相关联。PMv可以以上下文无关的方式为这些功能提供子服务，而MPFC可能主要在社会环境中这样做。
