Abstract:

Motor contagion, as a core mechanism of dynamic sensorimotor coupling in human social interaction, refers to the unconscious influence on one's own actions when observing others' movements, with its neural mechanisms and evolutionary significance remaining long-debated. Theoretical evolution reveals that its essence has shifted from the early “observation-execution” hard-coded imitation based on the mirror neuron system to adaptive behavioral regulation within the predictive processing framework: the brain generates predictions by constructing forward models and dynamically calibrates internal representations using error signals between actual sensory input and predictions, thereby explaining behavioral diversity ranging from imitation to strategic deviation. Within this framework, the dual-path model integrates an automatic path (unconscious imitation driven by the mirror system involving the ventral premotor cortex and inferior parietal lobule) and a conscious path (goal-directed behavior regulated by the prefrontal cortex); while the hierarchical processing model clarifies the primacy of intention—when higher-order intentions are clear, the influence of lower-order kinematic features on motor contagion diminishes. Research on neural mechanisms confirms that the mirror system initiates motor contagion through “observation-execution” neural matching, with its core functional mechanism—motor resonance—extending to intra-individual and interpersonal resonance, modulated by social cognition. Concurrently, the cerebellum plays a key role in predictive processing: its mossy fibers receive cortical prediction signals, while climbing fibers integrate real-time sensory feedback to generate prediction error signals uploaded to the cortex (forming a cortico-cerebellar loop) to update internal models. Notably, even non-biological motion cues can activate premotor cortex, highlighting the predictive system's capacity for generalization beyond biological attributes, towards physical motion laws. Social contextual factors exert fine-tuned control over motor contagion intensity via the prefrontal cortex: for instance, cooperative contexts enhance imitation (activating the left orbitofrontal cortex), while competitive contexts trigger behavioral inhibition (activating the right parietal cortex), profoundly reflecting the adaptive functionality endowed to this mechanism through evolution. The practical value of motor contagion underscores its cross-disciplinary potential: in sports, implicit observational design optimizes motor skill internalization by inducing prediction errors, and neurofeedback training enhances complex skill performance by modulating sensorimotor mu rhythms; in neurorehabilitation, action observation therapy combined with multisensory integration promotes functional reorganization of damaged neural networks by activating the mirror system, and the absence of an “interference transfer effect” can serve as a quantitative screening indicator for motor contagion deficits in autism spectrum disorder (ASD); in human-robot collaboration, leveraging motor contagion mechanisms (particularly the active inference framework), generative models can simulate intent prediction, advancing interaction paradigms from passive response towards predictive proactive synergy. Current core controversies focus on the necessity of the mirror neuron system—the occurrence of prediction error-driven behavioral deviations and effective contagion from non-biological cues suggest the mirror system may not be essential for motor contagion, but rather a replaceable node within dynamic neural networks. In summary, the essence of motor contagion lies in the dynamic interaction of perceptual, motor, and social cognitive networks under the predictive processing framework: the mirror system provides the motor resonance initiation signal, the predictive system endows behavioral flexibility through continuous minimization of prediction errors, and social context factors implement top-down adaptive regulation via the prefrontal cortex. Future research urgently requires deep interdisciplinary integration to build dynamic weighting models, combine more ecologically valid experimental paradigms, precisely quantify the regulatory effects of socio-cultural factors on motor contagion, thereby deepening the understanding of the embodied cognitive mechanisms of the “social brain” and promoting its innovative applications in fields such as digital twin training systems, neurorehabilitation, and human-robot collaboration.

Key words: motor contagion, neural mechanisms, mirror neuron system, predictive processing, social cognition