title: Vestibular and visual responses in human posterior insular cortex.
abstract: The central hub of the cortical vestibular network in humans is likely localized in the region of posterior lateral sulcus. An area characterized by responsiveness to visual motion has previously been described at a similar location and named posterior insular cortex (PIC). Currently it is not known whether PIC processes vestibular information as well. We localized PIC using visual motion stimulation in functional magnetic resonance imaging (fMRI) and investigated whether PIC also responds to vestibular stimuli. To this end, we designed an MRI-compatible caloric stimulation device that allowed us to stimulate bithermally with hot temperature in one ear and simultaneously cold temperature in the other or with warm temperatures in both ears for baseline. During each trial, participants indicated the presence or absence of self-motion sensations. We found activation in PIC during periods of self motion when vestibular stimulation was carried out with minimal visual input. In combined visual-vestibular stimulation area PIC was activated in a similar fashion during congruent and incongruent stimulation conditions. Our results show that PIC not only responds to visual motion but also to vestibular stimuli related to the sensation of self motion. We suggest that PIC is part of the cortical vestibular network and plays a role in the integration of visual and vestibular stimuli for the perception of self motion.
authors.affiliation: Institute for Experimental Psychology, University of Regensburg, Regensburg, Germany; Department of Psychological and Brain Sciences, Dartmouth College, Hanover, New Hampshire; and.
authors.forename: Sebastian M
authors.initials: SM
authors.lastname: Frank
authors.affiliation: Queensland Brain Institute and School of Psychology, The University of Queensland, St. Lucia, Australia.
authors.forename: Oliver
authors.initials: O
authors.lastname: Baumann
authors.affiliation: Queensland Brain Institute and School of Psychology, The University of Queensland, St. Lucia, Australia.
authors.forename: Jason B
authors.initials: JB
authors.lastname: Mattingley
authors.affiliation: Institute for Experimental Psychology, University of Regensburg, Regensburg, Germany; mark.greenlee@psychologie.uni-regensburg.de.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Greenlee
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004423:Ear / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods; D011434:Proprioception / Q000502:physiology*; D013696:Temperature; D013697:Thermosensing / Q000502:physiology
keywords: caloric stimulation; fMRI; multisensory integration; posterior insular cortex