title: Multisensory interactions between vestibular, visual and somatosensory signals.
abstract: Vestibular inputs are constantly processed and integrated with signals from other sensory modalities, such as vision and touch. The multiply-connected nature of vestibular cortical anatomy led us to investigate whether vestibular signals could participate in a multi-way interaction with visual and somatosensory perception. We used signal detection methods to identify whether vestibular stimulation might interact with both visual and somatosensory events in a detection task. Participants were instructed to detect near-threshold somatosensory stimuli that were delivered to the left index finger in one half of experimental trials. A visual signal occurred close to the finger in half of the trials, independent of somatosensory stimuli. A novel Near infrared caloric vestibular stimulus (NirCVS) was used to artificially activate the vestibular organs. Sham stimulations were used to control for non-specific effects of NirCVS. We found that both visual and vestibular events increased somatosensory sensitivity. Critically, we found no evidence for supra-additive multisensory enhancement when both visual and vestibular signals were administered together: in fact, we found a trend towards sub-additive interaction. The results are compatible with a vestibular role in somatosensory gain regulation.
authors: Institute of Cognitive Neuroscience, University College London, London, United Kingdom.
authors: Elisa Raffaella
authors: ER
authors: Ferrè
authors: Department of Otorhinolaryngology & Head and Neck Surgery, University Medicine Mannheim, University of Heidelberg, Mannheim, Germany.
authors: Leif Erik
authors: LE
authors: Walther
authors: Institute of Cognitive Neuroscience, University College London, London, United Kingdom.
authors: Patrick
authors: P
authors: Haggard
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D059906:Neuroimaging / Q000379:methods; D013003:Somatosensory Cortex / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D014722:Vestibule, Labyrinth / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*