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

这项拟议的研究将对猕猴、黑猩猩和人类的行为、大脑功能反应和镜像系统的解剖连接进行比较。镜像系统被认为是理解行为的基础，它允许个人模拟他人的行为，就好像他们正在执行这些行为一样。然而，几个悬而未决的问题限制了镜子系统与人类社会认知的联系程度。首先，猕猴镜面系统的结果在很大程度上是重复的。其次，猕猴和人类结果之间的等价性尚不清楚，因为它们涉及不同的方法。第三，猕猴和人类的镜子系统的反应不同，只有人类的镜子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的镜子系统有关的行为，最明显的是模仿。 这项提案将通过验证基本的猕猴镜子系统发现来解决前两个问题，方法与人类使用的方法类似。它将通过直接研究灵长类物种之间镜像系统的反应和连接性的不同来解决第二个问题。主要的假设是，通过增加与其他大脑网络的连接，镜像系统反应特性的进化拓宽，使这些细胞能够对更广泛的观察到的刺激做出反应，从而模拟更广泛的刺激。这一假设将使用行为任务、活体功能神经成像和结构扩散张量成像的组合进行验证。目标1将使用18F-FDG正电子发射断层扫描来比较猕猴和黑猩猩在有无物体的情况下执行和观察动作的神经相关性。目标1还将获得每个受试者的模仿能力行为指数。目标2将使用扩散张量成像来比较猕猴、黑猩猩和人类中连接镜像系统组件的白质路径。在目标1中获得的行为和功能大脑反应将与在目标2中获得的解剖学结果进行比较。这样，物种和个体在模仿能力上的差异可以与大脑反应和解剖连接的差异联系在一起。

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.