Department of Psychology, Harvard University, Cambridge, MA, USA.
Center for Mind/Brain Sciences (CIMeC), Università degli Studi di Trento, Rovereto, Italy.
Cereb Cortex. 2019 Jul 22;29(8):3434-3444. doi: 10.1093/cercor/bhy212.
The human high-level visual cortex comprises regions specialized for the processing of distinct types of stimuli, such as objects, animals, and human actions. How does this specialization emerge? Here, we investigated the role of effector-specific visuomotor coupling experience in shaping the organization of the action observation network (AON) as a window on this question. Observed body movements are frequently coupled with corresponding motor codes, e.g., during monitoring one's own movements and imitation, resulting in bidirectionally connected circuits between areas involved in body movements observation (e.g., of the hand) and the motor codes involved in their execution. If the organization of the AON is shaped by this effector-specific visuomotor coupling, then, it should not form for body movements that do not belong to individuals' motor repertoire. To test this prediction, we used fMRI to investigate the spatial arrangement and functional properties of the hand and foot action observation circuits in individuals born without upper limbs. Multivoxel pattern decoding, pattern similarity, and univariate analyses revealed an intact hand AON in the individuals born without upper limbs. This suggests that the organization of the AON does not require effector-specific visuomotor coupling.
人类的高级视觉皮层包含专门用于处理不同类型刺激的区域，例如物体、动物和人类动作。这种专业化是如何出现的？在这里，我们研究了效应器特异性运动耦合经验在塑造动作观察网络 (AON) 组织中的作用，将其作为研究这个问题的窗口。观察到的身体运动经常与相应的运动代码相耦合，例如，在监测自己的运动和模仿时，导致参与身体运动观察的区域（例如手）和参与其执行的运动代码之间形成双向连接的电路。如果 AON 的组织是由这种效应器特异性的运动耦合塑造的，那么它不应该形成不属于个体运动技能库的身体运动。为了检验这一预测，我们使用 fMRI 研究了出生时没有上肢的个体的手部和脚部动作观察回路的空间排列和功能特性。多体素模式解码、模式相似性和单变量分析显示，出生时没有上肢的个体的手部 AON 是完整的。这表明 AON 的组织不需要效应器特异性的运动耦合。
