School of Cognitive Sciences, Institute for Research in Fundamental Sciences, Tehran 1956836484, Iran.
Laboratory of Biological Psychology, Department of Brain and Cognition, Leuven Brain Institute, Katholieke Universiteit Leuven, Leuven 3714, Belgium.
Cereb Cortex. 2023 Feb 7;33(4):1462-1475. doi: 10.1093/cercor/bhac149.
Humans can recognize others' actions in the social environment. This action recognition ability is rarely hindered by the movement of people in the environment. The neural basis of this position tolerance for observed actions is not fully understood. Here, we aimed to identify brain regions capable of generalizing representations of actions across different positions and investigate the representational content of these regions. In a functional magnetic resonance imaging experiment, participants viewed point-light displays of different human actions. Stimuli were presented in either the upper or the lower visual field. Multivariate pattern analysis and a surface-based searchlight approach were employed to identify brain regions that contain position-tolerant action representation: Classifiers were trained with patterns in response to stimuli presented in one position and were tested with stimuli presented in another position. Results showed above-chance classification in the left and right lateral occipitotemporal cortices, right intraparietal sulcus, and right postcentral gyrus. Further analyses exploring the representational content of these regions showed that responses in the lateral occipitotemporal regions were more related to subjective judgments, while those in the parietal regions were more related to objective measures. These results provide evidence for two networks that contain abstract representations of human actions with distinct representational content.
人类能够在社会环境中识别他人的动作。这种动作识别能力很少受到环境中人物运动的阻碍。对于这种观察到的动作的位置容忍的神经基础还不完全清楚。在这里，我们旨在确定能够跨不同位置概括动作表示的大脑区域，并研究这些区域的表示内容。在一项功能磁共振成像实验中，参与者观看了不同人类动作的光点显示。刺激物分别在上部或下部视野中呈现。采用多变量模式分析和基于表面的搜索灯方法来识别包含位置容忍动作表示的大脑区域：使用在一个位置呈现的刺激物响应的模式训练分类器，并使用在另一个位置呈现的刺激物进行测试。结果表明，在左侧和右侧外侧枕颞皮质、右侧顶内沟和右侧中央后回中，分类器的分类结果超过了随机水平。进一步探索这些区域表示内容的分析表明，外侧枕颞区域的反应与主观判断更相关，而顶叶区域的反应与客观测量更相关。这些结果为包含人类动作的抽象表示的两个网络提供了证据，这些网络具有不同的表示内容。
