Observing self and other body motion modulates vestibular information processing

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• 作者：Estelle Nakul ; Diane Deroualle ; Christophe Lopez ; ^{christophe.lopez@univ-amu.fr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Vestibular system ; Neurophysiology ; Social cognition ; Vestibular-evoked myogenic potentials
• 刊名：Neurophysiologie Clinique / Clinical Neurophysiology
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：46
• 期：4-5
• 页码：271
• 全文大小：52 K

文摘

Recent studies have highlighted the vestibular contributions to cognition, affective control and self-consciousness (Lopez, 2016), but only few studies measured how cognition influences vestibular information processing. There is to date no neurophysiological study linking vestibular processing and social cognition. This is surprising given that humans are often surrounded by other individuals in motion and that vestibular-defective patients frequently report discomfort while surrounded by other individuals in motion (Lopez et al., 2015). Here, we studied how observing passive motion of human bodies influences vestibular information processing by measuring vestibulo-spinal excitability.

Material and methods

Twenty-five healthy volunteers were shown in a head-mounted display 6-second videos depicting passive rotations of their own body (“self” videos), someone else's body (“other” video) or an object (“object” video). At the same time, they received repeated galvanic vestibular stimulation (8 Hz, 4 mA) over the mastoid processes, which stimulates vestibular nerve afferents. Galvanic stimulation evokes short latency vestibulo-spinal reflexes (i.e. vestibular-evoked myogenic potentials, VEMPs ; Welgampola and Colebatch, 2005) that were recorded with electromyography electrodes over the sternocleidomastoid and trapezius muscles.

Results

VEMPs amplitude was significantly reduced for “self” and “other” videos when compared to “object” videos. VEMPs were even smaller for “self” than “other” videos, revealing a social modulation of vestibular information processing.

Discussion–conclusion

Our results show that vestibulo-spinal reflexes are modulated by top-down influences. This study provides the first evidence that social cognition has a pre-reflective influence on vestibular processing. Patients with vestibular disorders experience unbalance when surrounded by moving crowds. Our preliminary results suggest new paths for the understanding and therapy of vestibular symptoms.