Cortical Contributions to Local and Global Biological Motion Perception: Insights from Transcranial Magnetic Stimulation

Humans have an extraordinary ability to detect and recognize biological motion (BM). This sophisticated perception relies on two fundamental visual cues: local kinematics and global structure-from-motion information, which are processed along subcortical-cortical pathways. However, it remains unclear how key motion-sensitive regions, such as the posterior superior temporal sulcus (pSTS) and the medial temporal complex (MT+), contribute to the processing of distinct BM cues. In this study, we employed transcranial magnetic stimulation (TMS) to explore the causal roles of these two cortical regions in BM perception. TMS was delivered to the pSTS and MT+, which were individually localized in the right hemisphere, and participants performed direction discrimination tasks with intact BM, scrambled BM, and simple coherent motion stimuli. Results demonstrated that TMS over the pSTS selectively impaired intact BM discrimination, whereas MT+ stimulation only disrupted coherent motion perception. Importantly, neither site showed significant impairment in scrambled BM direction discrimination. These findings suggest that while pSTS and MT+ are critical for global BM and coherent motion perception, respectively, they are not obligatory for local BM processing. The detection of local BM signals may rely on a specialized mechanism operating at an early stage of visual processing.人类拥有卓越的检测与识别生物运动（Biological Motion, BM）的能力。这种复杂的感知能力依赖于两类核心视觉线索：局部运动学信息与基于运动的全局结构信息，相关信息会经由皮层下-皮层通路进行处理。然而，学界仍未明确关键的运动敏感脑区——如后侧颞上沟（posterior superior temporal sulcus, pSTS）与内侧颞叶复合区（medial temporal complex, MT+）——是如何参与处理不同类型的生物运动线索的。本研究采用经颅磁刺激（transcranial magnetic stimulation, TMS）技术，探究这两个皮层区域在生物运动感知中的因果性作用。我们将经颅磁刺激精准施加于右侧半球内分别定位的pSTS与MT+脑区，同时让被试完成三类刺激下的方向辨别任务：完整生物运动、打乱结构的生物运动以及简单连贯运动刺激。实验结果显示，对pSTS施加经颅磁刺激会选择性损伤完整生物运动的辨别能力，而MT+刺激仅会破坏连贯运动感知。值得注意的是，对两个脑区施加刺激均未对打乱结构的生物运动的方向辨别造成显著损伤。上述结果表明，尽管pSTS与MT+分别是全局生物运动感知与连贯运动感知的关键脑区，但二者并非局部生物运动处理的必需通路。局部生物运动信号的检测或许依赖于视觉处理早期阶段的一种专属机制。

搜集汇总

背景与挑战

背景概述

该数据集通过经颅磁刺激（TMS）研究大脑皮层区域对生物运动感知的贡献，重点关注后颞上沟（pSTS）和内侧颞复合体（MT+）。实验结果表明，pSTS对全局生物运动感知起关键作用，而MT+主要影响连贯运动感知，两者均不直接参与局部生物运动处理。这揭示了皮层区域在生物运动感知中的特异性功能分工，局部信号可能依赖早期视觉机制。