title: Inter-hemispheric desynchronization of the human MT+ during visually induced motion sickness.
abstract: 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.
authors.affiliation: Corporate R&D, Canon Inc., Tokyo, Japan.
authors.forename: Jungo
authors.initials: J
authors.lastname: Miyazaki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Ichimura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamashiro
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Murase
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Masahiro
authors.initials: M
authors.lastname: Umeda
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Higuchi
mesh_terms: D000328:Adult; D003344:Cortical Synchronization / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D009041:Motion Sickness / Q000503:physiopathology*; D017120:Nystagmus, Optokinetic / Q000502:physiology*; D013702:Temporal Lobe / Q000503:physiopathology*; D014793:Visual Cortex / Q000503:physiopathology*