关键词: 生物运动, 拍子同步, 整体构型, 局部运动

Abstract: Humans possess an inherent ability to detect biological motion (BM) in their environment and synchronize with its rhythm, even when it is represented by a simplified set of light points. Point-light biological motion, despite its simplification, contains both global configuration and local motion trajectories, which are crucial for perception. While previous research has advanced our understanding of biological motion processing, few studies have thoroughly investigated the relative contributions of global configuration and local motion in beat synchronization with biological motion. The aim of this study was to examine the mechanisms involved in the interaction between global configuration and local motion information during beat synchronization with biological motion. This research included three experiments with 30, 27, and 33 Chinese participants in Experiments 1, 2, and 3, respectively. All three experiments employed a beat synchronization paradigm, where participants were asked to simultaneously perform beat synchronization tasks and change detection tasks. The experimental materials in Experiment 1 consisted of standard BM, scrambled BM, and inverted scrambled BM. Experiment 2 involved scrambled BM, inverted scrambled BM, and scrambled uniform BM, while Experiment 3 included standard BM, unscrambled uniform BM, scrambled BM, and scrambled uniform BM. The primary dependent variable in all experiments was the stability of beat synchronization. Experiment 1 revealed that the stability of beat synchronization under the standard BM condition was significantly higher compared to the scrambled BM and inverted scrambled BM conditions. This finding highlights the critical role of global configuration information in the synchronization process. Experiment 2 found that when the global configuration is disrupted, neither the preservation nor alterations to local motion information—whether through disrupting the biological nature of motion direction (inversion) or speed variation patterns (eliminating acceleration)—had a significant effect on the stability of beat synchronization with biological motion. In other words, the absence of global configuration information might limit the role of local motion in stabilizing synchronization. A significant interaction between global configuration and local motion was observed in Experiment 3. When the global configuration was intact, the disruption of local motion (eliminating acceleration) resulted in a marked decrease in beat synchronization stability. However, when the global configuration was disrupted, the biological nature of local motion did not have a significant effect on synchronization stability. This suggests global configuration might be a prerequisite for the functioning of local motion information. In conclusion, the present study demonstrated that beat synchronization with biological motion is modulated by both global configuration and local motion, with the global configuration exerting a dominant influence. The findings can be interpreted through the lens of Bayesian theory: when the global configuration of biological motion remains intact, human-like information activates pre-existing brain templates, thereby providing prior knowledge, while local motion offers likelihood information that aligns with these predictions. This facilitates more efficient sensorimotor timing, as reflected in enhanced stability of beat synchronization. In contrast, when the biological nature of local motion is disrupted or the global configuration is compromised, the brain fails to activate these templates, resulting in no differential performance in synchronization. These results are consistent with Bayesian theory and offer a novel perspective on the mechanisms underlying biological motion perception.

Key words: biological motion, beat synchronization, global configuration, local motion