Galvanic Vestibular Stimulation Elicits Consistent Head-Neck Motion in Seated Subjects

• Published in: IEEE transactions on biomedical engineering Vol. 59; no. 7; pp. 1978 - 1984
• Main Authors: Ehtemam, Farzad, Forbes, Patrick A., Schouten, Alfred C., van der Helm, Frans C.T., Happee, Riender
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.2012; Institute of Electrical and Electronics Engineers
• Subjects: Adolescent; Adult; Analysis of Variance; Applied sciences; Coherence; Detection, estimation, filtering, equalization, prediction; Electric Stimulation - instrumentation; Electric Stimulation - methods; Electrodes; Exact sciences and technology; Female; Galvanic vestibular stimulation (GVS); Head Movements - physiology; head stabilization; Humans; Information, signal and communications theory; Kinematics; Magnetic heads; Male; Muscles; Neck; Neck - physiology; neck reflexes and system identification; Postural Balance - physiology; Posture; Signal and communications theory; Signal, noise; Statistics, Nonparametric; Telecommunications and information theory; Torso; Vestibule, Labyrinth - physiology; Human; Head position; neck reflexes and system identification; Stabilization; Head and neck; head stabilization; Neck; System identification; Galvanic vestibular stimulation (GVS); Biomedical engineering
• ISSN: 0018-9294; 1558-2531; 1558-2531
• DOI: 10.1109/TBME.2012.2195178

Humans actively stabilize the head-neck system based on vestibular, proprioceptive and visual information. Galvanic vestibular stimulation (GVS) has been used previously to demonstrate the role of vestibular feedback in standing balance. This study explores the effect of GVS on head-neck kinematics and evaluates the approach to investigate the vestibular contribution to head-neck stabilization. GVS was applied to 11 seated subjects using seven different stimuli (single sinusoids and multisines) at amplitudes of 0.5-2 mA and frequencies of 0.4-5.2 Hz using a bilateral bipolar configuration while 3-D head and torso kinematics were recorded using motion capture. System identification techniques were used evaluating coherence and frequency response functions (FRFs). GVS resulted in significant coherence in roll, yaw and lateral translation, consistent with effects of GVS while standing as reported in the literature. The gain of the FRFs varied with frequency and no modulation was observed across the stimulus amplitudes, indicating a linear system response for the stimulations considered. Compared to single sine stimulation, equivalent FRFs were observed during unpredictable multisine stimulation, suggesting the responses during both stimuli to be of a reflexive nature. These results demonstrate the potential of GVS to investigate the vestibular contribution to head-neck stabilization.