Comparison of Postural Responses to Galvanic Vestibular Stimulation between Pilots and the General Populace

Abstract

Galvanic vestibular stimulation (GVS) can be used to study the body's response to vestibular stimuli. This study aimed to investigate whether postural responses to GVS were different between pilots and the general populace. Bilateral bipolar GVS was applied with a constant-current profile to 12 pilots and 12 control subjects via two electrodes placed over the mastoid processes. Both GVS threshold and the center of pressure's trajectory (COP's trajectory) were measured. Position variability of COP during spontaneous body sway and peak displacement of COP during GVS-induced body sway were calculated in the medial-lateral direction. Spontaneous body sway was slight for all subjects, and there was no significant difference in the value of COP position variability between the pilots and controls. Both the GVS threshold and magnitude of GVS-induced body deviation were similar for different GVS polarities. GVS thresholds were similar between the two groups, but the magnitude of GVS-induced body deviation in the controls was significantly larger than that in the pilots. The pilots showed less GVS-induced body deviation, meaning that pilots may have a stronger ability to suppress vestibular illusions.

Techniques and Methods for Testing the Postural Function in Healthy and Pathological Subjects

“…It consists of provoking neurosensory conflicts by applying an electrical current via surface electrodes to the mastoid processes [ 118 , 119 , 123 ]. This electrical current disturbs the transduction of ciliated cells in ampullary crests (in semicircular canals) and macula (in otoliths) which induces body motion illusions [ 123 , 124 ] and modifies postural attitude [ 125 – 127 ] but does not change the internal representation of the subjective vertical [ 127 ]. Galvanic vestibular stimulation can be applied unilaterally or bilaterally through monopolar or bipolar stimulus [ 128 , 129 ].…”

“…The delay in postural response to stimulation is about 1-2 s [ 124 ]. The experience of more natural stimulation of the vestibular system, that is, through accelerations of the head movement through specific physical activities (e.g., control subjects versus pilots), can limit the magnitude of body deviation [ 125 ]. This study showed that pilots have a stronger ability to suppress vestibular illusions than control subjects.…”

Postural Effects of Vestibular Manipulation Depend on the Physical Activity Status

“…young professional gymnast) than control participants on postural balance. In addition, Yang et al [ 58 ] also showed that experienced airplane pilots demonstrated less postural balance alteration to withstand GVS than control participants. However, Maitre et al [ 31 ] found no difference between physically active participants (i.e.…”

“…Balter et al [ 51 ] showed that postural differences with a current intensity of 2 mA. Yang et al [ 58 ] also demonstrated differences with a maximal current intensity of 1.2 mA. Maitre et al [ 31 ] demonstrated no differences with a current intensity of 1 mA.…”

Efficacy of Trans-Mastoidal Vestibular Galvanic Stimulation in Improvement of Gait Performance and Upright Postural Stability in Hemiplegic C.P. Children

“…The response of GVS is low when the patient is but has a great effect during walking. This is an indicator that vestibular apparatus is very vital during walking more than during 40] GVS could stimulate the semicircular canal which evoked by angular acceleration and head velocity also could stimulate the static utricle and saccule which evoked by linear acceleration and head tilt [41].…”