Dynamic brain connectivity: linking inter-group difference and individual susceptibility changes in visually induced motion sickness susceptibility.

Visually induced motion sickness (VIMS) is a prevalent discomfort experienced in virtual environments, and individual susceptibility to VIMS can change with training or experience. Currently, the neurological activities that respond to susceptibility changes remain unclear. This study identified dynamic brain connectivity that consistently responded to inter-group susceptibility differences as well as individual susceptibility changes. Participants with varying susceptibility to VIMS underwent adaptation training, which involved repeated exposure to roll rotation stimulation for 7-10 days. VIMS susceptibility and Theta-band EEG phase synchronization were measured before and after the adaptation training. The results revealed that the inter-hemispheric connectivity in temporal-parietal regions not only significantly differed between the susceptible and resistant groups, but also increased with individual resistance enhancement. The strength of this connectivity was negatively correlated to individual level of VIMS symptoms. Machine learning models based on whole brain connection patterns effectively identified susceptible individuals and tracked changes in susceptibility following training. All effects were also observed in untrained stimulus type, indicating the robustness of the connectivity indicators. These findings underscore the importance of inter-hemispheric coordination in VIMS and highlight the potential of EEG phase synchronization as a tool for testing and monitoring individual susceptibility to VIMS. The online version contains supplementary material available at 10.1007/s11571-025-10354-7.