Abstract
<title>Abstract</title> <p>Background Action observation is associated with changes in sensorimotor EEG rhythms, including suppression of the central mu rhythm. Immersive virtual reality (IVR) provides an enriched perceptual context for action observation and may influence sensorimotor oscillatory responses during the viewing of complex human movements. However, few studies have directly compared immersive, live, and conventional 2D observation using the same complex motor stimulus. Methods Thirty-six healthy, right-handed female novices were randomly assigned to one of three observation conditions: IVR, live observation, or 2D video observation. Participants observed a standardized Karate Kata sequence while EEG activity was recorded from central sensorimotor sites. Mu rhythm suppression in the 8–13 Hz band over C3, Cz, and C4 was calculated relative to resting baseline and compared across observation modalities. An exploratory theta-to-beta ratio analysis was also performed as an EEG-derived index related to attentional state. Results Observation modality significantly affected central mu rhythm suppression. The IVR condition showed greater mu suppression than both live observation and 2D video observation, whereas live and 2D observation did not significantly differ. Mu suppression did not differ significantly across C3, Cz, and C4 within each modality. The exploratory theta-to-beta ratio did not differ significantly across observation modalities. Conclusions These findings indicate that immersive observation of a complex whole-body action is associated with stronger central mu rhythm suppression than live or 2D observation. By showing that observation format can modulate sensorimotor oscillatory activity during action observation, this study supports the potential value of IVR as an experimental platform for investigating embodied and sensorimotor aspects of observed movement. These findings may inform the design of future IVR-based action-observation protocols for motor training and rehabilitation research.</p>