Department of Experimental Clinical and Health Psychology, Ghent University, Ghent 9000, Belgium.
Department of Psychology, Goldsmiths, University of London, London SE14 6NW, UK.
Soc Cogn Affect Neurosci. 2023 Mar 22;18(1). doi: 10.1093/scan/nsad014.
Although the ability to detect the actions of other living beings is key for adaptive social behavior, it is still unclear if biological motion perception is specific to human stimuli. Biological motion perception involves both bottom-up processing of movement kinematics ('motion pathway') and top-down reconstruction of movement from changes in the body posture ('form pathway'). Previous research using point-light displays has shown that processing in the motion pathway depends on the presence of a well-defined, configural shape (objecthood) but not necessarily on whether that shape depicts a living being (animacy). Here, we focused on the form pathway. Specifically, we combined electroencephalography (EEG) frequency tagging with apparent motion to study how objecthood and animacy influence posture processing and the integration of postures into movements. By measuring brain responses to repeating sequences of well-defined or pixelated images (objecthood), depicting human or corkscrew agents (animacy), performing either fluent or non-fluent movements (movement fluency), we found that movement processing was sensitive to objecthood but not animacy. In contrast, posture processing was sensitive to both. Together, these results indicate that reconstructing biological movements from apparent motion sequences requires a well-defined but not necessarily an animate shape. Instead, stimulus animacy appears to be relevant only for posture processing.
虽然能够检测其他生物的行为对于适应性的社会行为至关重要，但生物运动知觉是否专门针对人类刺激仍然不清楚。生物运动知觉既涉及运动运动学的自下而上的处理（“运动途径”），也涉及从身体姿势的变化中重建运动的自上而下的重构（“形式途径”）。先前使用点光显示的研究表明，运动途径的处理取决于存在定义明确的、整体的形状（物体性），但不一定取决于该形状是否描绘了一个生物（生物性）。在这里，我们专注于形式途径。具体来说，我们结合脑电图（EEG）频率标记和明显运动来研究物体性和生物性如何影响姿势处理以及姿势如何融入运动。通过测量大脑对重复的定义明确或像素化图像序列（物体性）、描绘人类或螺旋桨代理（生物性）、执行流畅或非流畅运动（运动流畅性）的反应，我们发现运动处理对物体性敏感，但对生物性不敏感。相比之下，姿势处理对两者都敏感。这些结果表明，从明显的运动序列中重建生物运动需要一个定义明确但不一定是有生命的形状。相反，刺激的生物性似乎仅与姿势处理有关。
