title: Differential effect of visual motion adaption upon visual cortical excitability.
abstract: The objectives of this study were1) to probe the effects of visual motion adaptation on early visual and V5/MT cortical excitability and2) to investigate whether changes in cortical excitability following visual motion adaptation are related to the degree of visual dependency, i.e., an overreliance on visual cues compared with vestibular or proprioceptive cues. Participants were exposed to a roll motion visual stimulus before, during, and after visual motion adaptation. At these stages, 20 transcranial magnetic stimulation (TMS) pulses at phosphene threshold values were applied over early visual and V5/MT cortical areas from which the probability of eliciting a phosphene was calculated. Before and after adaptation, participants aligned the subjective visual vertical in front of the roll motion stimulus as a marker of visual dependency. During adaptation, early visual cortex excitability decreased whereas V5/MT excitability increased. After adaptation, both early visual and V5/MT excitability were increased. The roll motion-induced tilt of the subjective visual vertical (visual dependence) was not influenced by visual motion adaptation and did not correlate with phosphene threshold or visual cortex excitability. We conclude that early visual and V5/MT cortical excitability is differentially affected by visual motion adaptation. Furthermore, excitability in the early or late visual cortex is not associated with an increase in visual reliance during spatial orientation. Our findings complement earlier studies that have probed visual cortical excitability following motion adaptation and highlight the differential role of the early visual cortex and V5/MT in visual motion processing.NEW & NOTEWORTHYWe examined the influence of visual motion adaptation on visual cortex excitability and found a differential effect in V1/V2 compared with V5/MT. Changes in visual excitability following motion adaptation were not related to the degree of an individual's visual dependency.
authors.affiliation: Academic Department of Neuro-Otology, Division of Brain Sciences, Charing Cross Hospital Campus, Imperial College London, London, United Kingdom.|Research Institute MOVE, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
authors.forename: Astrid J A
authors.initials: AJ
authors.lastname: Lubeck
authors.affiliation: Academic Department of Neuro-Otology, Division of Brain Sciences, Charing Cross Hospital Campus, Imperial College London, London, United Kingdom.|Antwerp University Research Centre for Equilibrium and Aerospace (AUREA), University of Antwerp, Antwerp, Belgium; and.
authors.forename: Angelique
authors.initials: A
authors.lastname: Van Ombergen
authors.affiliation: Academic Department of Neuro-Otology, Division of Brain Sciences, Charing Cross Hospital Campus, Imperial College London, London, United Kingdom.
authors.forename: Hena
authors.initials: H
authors.lastname: Ahmad
authors.affiliation: Research Institute MOVE, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.|TNO Perceptual and Cognitive Systems, Soesterberg, The Netherlands.
authors.forename: Jelte E
authors.initials: JE
authors.lastname: Bos
authors.affiliation: Antwerp University Research Centre for Equilibrium and Aerospace (AUREA), University of Antwerp, Antwerp, Belgium; and.
authors.forename: Floris L
authors.identifier: 0000-0002-4485-6412
authors.initials: FL
authors.lastname: Wuyts
authors.affiliation: Academic Department of Neuro-Otology, Division of Brain Sciences, Charing Cross Hospital Campus, Imperial College London, London, United Kingdom; a.bronstein@imperial.ac.uk.
authors.forename: Adolfo M
authors.initials: AM
authors.lastname: Bronstein
authors.affiliation: Academic Department of Neuro-Otology, Division of Brain Sciences, Charing Cross Hospital Campus, Imperial College London, London, United Kingdom.
authors.forename: Qadeer
authors.initials: Q
authors.lastname: Arshad
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000071080:Cortical Excitability; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception; D010719:Phosphenes; D010775:Photic Stimulation; D050781:Transcranial Magnetic Stimulation; D014793:Visual Cortex / Q000502:physiology*; D055815:Young Adult
keywords: V5/MT; cortical excitability; early visual cortex; transcranial magnetic stimulation; visual dependency; visual motion adaptation