映像に酔うと右脳と左脳の活動が乖離する現象を発見 -安全で快適な高臨場感映像技術開発の足がかりに-. 京都大学プレスリリース. 2015-05-26.Visually induced motion sickness (VIMS) is triggered in susceptible individuals by stationary viewing of moving visual scenes. VIMS is often preceded by an illusion of self-motion (vection) and/or by inappropriate optokinetic nystagmus (OKN) responses associated with increased activity in the human motion-sensitive middle temporal area (MT+). Neuroimaging studies have reported predominant right hemispheric activation in MT+ during both vection and OKN, suggesting that VIMS may result from desynchronization of activity between left and right MT+ cortices. However, this possibility has not been directly tested. To this end, we presented VIMS-free and VIMS-inducing movies in that order while measuring the temporal correlations between corresponding left and right visual cortices (including MT+) using functional magnetic resonance imaging. The inter-hemispheric correlation was reduced significantly during the viewing of the VIMS-inducing movie compared to the control VIMS-free movie in the MT+ of subjects reporting VIMS, but not in insusceptible subjects. In contrast, there were no significant inter-hemispheric differences within VIMS-free or VIMS-inducing movie exposure for visual area V1, V2, V3, V3A or V7. Our findings provide the first evidence for an association between asynchronous bilateral MT+ activation and VIMS. Desynchronization of left and right MT+ regions may reflect hemispheric asymmetry in the activities of functional networks involved in eye movement control, vection perception and/or postural control.