Neural Correlates of Action Perception: Brain Structure, Function, and Behavior

这项拟议中的研究将比较猕猴、黑猩猩和人类在镜像系统中的行为、功能性大脑反应和解剖连通性。镜像系统被认为是行为理解的基础，它允许个体模仿他人的行为，就好像他们在表演一样。然而，一些尚未解决的问题限制了镜像系统与人类社会认知的联系程度。首先，猕猴镜像系统的结果在很大程度上是重复的。其次，猕猴和人类的结果是否相同尚不清楚，因为它们涉及不同的方法。第三，猕猴和人类镜像系统的反应不同，只有人类镜像系统对不涉及物体的动作做出反应。第四，猕猴缺乏一些与人类镜像系统相关的行为，最明显的是模仿。

The proposed research will compare behavior, functional brain responses, and anatomical connectivity in the mirror system in macaques, chimpanzees, and humans. The mirror system is thought to underlie action understanding by allowing individuals to simulate others' actions as if they were performing them. However, several unresolved issues limit the extent to which the mirror system can be linked to human social cognition. First, macaque mirror system results are largely replicated. Second, the equivalence between macaque and human results is unclear because they involve different methodologies. Third, macaque and human mirror system responses differ, with only the human mirror system responding to actions that do not involve objects. Fourth, macaques lack some behaviors which have been linked to the mirror system in humans, most notably imitation. This proposal will address the first two issues by validating basic macaque mirror system findings using a methodology comparable to those used in humans. It will address the second two issues by directly investigating how mirror system responses and connectivity differ among primate species. The main hypothesis is that an evolved broadening in mirror system response properties, via increased connectivity with other brain networks, allowed these cells to respond to, and thus simulate, a wider variety of observed stimuli. This hypothesis will be tested using a combination of behavioral tasks, in vivo functional neuroimaging, and structural diffusion tensor imaging. Aim 1 will employ 18F-FDG positron emission tomography to compare the neural correlates of the execution and observation of actions with and without objects in macaques and chimpanzees. Aim 1 will also procure behavioral indices of imitation ability in each subject. Aim 2 will use diffusion tensor imaging to compare white matter pathways linking the components of the mirror system in macaques, chimpanzees, and humans. The behavioral and functional brain responses obtained in Aim 1 will be compared to the anatomical results obtained in Aim 2. In this way, species and individual differences in imitation ability can be linked to differences in brain responses and anatomical connectivity.