Shen Li, Li Shuo, Tian Yuhao, Wang Ying, Jiang Yi
State Key Laboratory of Cognitive Science and Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
Elife. 2025 Feb 5;13:RP98701. doi: 10.7554/eLife.98701.
When observing others' behaviors, we continuously integrate their movements with the corresponding sounds to enhance perception and develop adaptive responses. However, how the human brain integrates these complex audiovisual cues based on their natural temporal correspondence remains unclear. Using electroencephalogram (EEG), we demonstrated that rhythmic cortical activity tracked the hierarchical rhythmic structures in audiovisually congruent human walking movements and footstep sounds. Remarkably, the cortical tracking effects exhibit distinct multisensory integration modes at two temporal scales: an additive mode in a lower-order, narrower temporal integration window (step cycle) and a super-additive enhancement in a higher-order, broader temporal window (gait cycle). Furthermore, while neural responses at the lower-order timescale reflect a domain-general audiovisual integration process, cortical tracking at the higher-order timescale is exclusively engaged in the integration of biological motion cues. In addition, only this higher-order, domain-specific cortical tracking effect correlates with individuals' autistic traits, highlighting its potential as a neural marker for autism spectrum disorder. These findings unveil the multifaceted mechanism whereby rhythmic cortical activity supports the multisensory integration of human motion, shedding light on how neural coding of hierarchical temporal structures orchestrates the processing of complex, natural stimuli across multiple timescales.
在观察他人行为时，我们不断将他们的动作与相应的声音整合起来，以增强感知并形成适应性反应。然而，人类大脑如何基于自然的时间对应关系整合这些复杂的视听线索仍不清楚。我们利用脑电图（EEG）证明，节律性皮层活动跟踪了视听一致的人类行走动作和脚步声中的分层节律结构。值得注意的是，皮层跟踪效应在两个时间尺度上表现出不同的多感官整合模式：在较低阶、较窄的时间整合窗口（步周期）中为相加模式，在较高阶、较宽的时间窗口（步态周期）中为超相加增强。此外，虽然较低阶时间尺度上的神经反应反映了一种通用的视听整合过程，但较高阶时间尺度上的皮层跟踪专门参与生物运动线索的整合。此外，只有这种高阶、特定领域的皮层跟踪效应与个体的自闭症特征相关，突出了其作为自闭症谱系障碍神经标志物的潜力。这些发现揭示了节律性皮层活动支持人类运动多感官整合的多方面机制，阐明了分层时间结构的神经编码如何在多个时间尺度上协调复杂自然刺激的处理。
