Smekal Vojtěch, Poyo Solanas Marta, de Gelder Beatrice
Department of Cognitive Neuroscience, Maastricht University, Oxfordlaan, Maastricht 6229EV, The Netherlands.
PNAS Nexus. 2025 Mar 24;4(3):pgaf067. doi: 10.1093/pnasnexus/pgaf067. eCollection 2025 Mar.
Human action perception involves processing dynamic information in its temporal order. However, previous studies investigating action perception have not yet distinguished between the presence of dynamic information and the temporal order in which dynamic information unfolds within the context of a single action. Using 3-T functional MRI, we presented participants with brief, single-actor, whole-body actions viewed either as still images, as intact videos, or as videos consisting of short dynamic fragments with the order temporally scrambled. Regions classically associated with action perception showed higher activity for dynamic compared with still stimuli, regardless of the temporal continuity in the dynamic stimuli. However, two clusters in the right inferior parietal lobule (IPL) differentiated between the intact and temporally scrambled videos. Specifically, the right angular gyrus (AG) showed a preference for the intact videos over the temporally scrambled ones, while the right supramarginal gyrus (SMG) showed the opposite pattern. Combined with previous literature, we argue for the role of the IPL as a temporospatial buffer, with the SMG processing dynamic information on short timescales and the AG processing on longer timescales. Our results underscore the need to consider dynamic information and temporal order separately in investigations of action perception.
人类动作感知涉及按时间顺序处理动态信息。然而，以往研究动作感知的实验尚未区分动态信息的存在与动态信息在单个动作情境中展开的时间顺序。我们使用3-T功能磁共振成像，向参与者展示简短的、单演员全身动作，这些动作以静态图像、完整视频或由时间顺序被打乱的短动态片段组成的视频形式呈现。经典上与动作感知相关的脑区，对于动态刺激比静态刺激表现出更高的激活，无论动态刺激中的时间连续性如何。然而，右侧顶下小叶（IPL）中的两个脑区簇区分了完整视频和时间顺序被打乱的视频。具体而言，右侧角回（AG）对完整视频的偏好高于时间顺序被打乱的视频，而右侧缘上回（SMG）则表现出相反的模式。结合先前的文献，我们认为IPL起到时空缓冲的作用，其中SMG在短时间尺度上处理动态信息，而AG在较长时间尺度上进行处理。我们的结果强调在动作感知研究中需要分别考虑动态信息和时间顺序。
