Wood Scott J, Black F Owen, MacDougall Hamish G, Moore Steven T
Universities Space Research Association, NASA Johnson Space Center, Houston, Texas 77058, USA.
Ann N Y Acad Sci. 2009 May;1164:492-8. doi: 10.1111/j.1749-6632.2009.03768.x.
The purpose of this study was to assess the influence of electrotactile feedback on postural control performance during binaural galvanic vestibular stimulation (GVS). Postural equilibrium was measured with a computerized hydraulic platform in 10 healthy adults (6M, 4F, 24-65 y). Feedback of anterior-posterior (AP) and mediallateral (ML) body sway was derived from a 2-axis linear accelerometer mounted on a torso belt and displayed on a 144-point electrotactile array held against the anterior dorsal tongue. Subjects were trained to use the tongue electrotactile feedback (TEF) by voluntarily swaying to draw figures on their tongue, both with and without GVS. Subjects performed 24 randomized trials (20-s duration with eyes closed, 2 trials per condition), including 4 support surface conditions (fixed, rotational sway-referenced, translating the support surface proportional to AP sway, and combined rotational-translational support-platform sway referencing), and 3 feedback conditions (baseline, GVS, and GVS with TEF). Postural performance was assessed using deviations from upright (peak-to-peak and root-mean-square sway) and convergence toward stability limits (time and distance to limit of support boundaries). Postural stability was impaired (with respect to baseline) during GVS in all platform conditions, with larger decrements in performance during trials with rotation sway-referencing. Electrotactile feedback improved performance with GVS toward non-GVS levels, especially during trials with rotation sway-referencing. These results demonstrate the effectiveness of TEF in providing sensory substitution to maintain postural stability during vestibular disturbances.
本研究的目的是评估在双耳直流电前庭刺激（GVS）期间，电触觉反馈对姿势控制性能的影响。使用计算机化液压平台对10名健康成年人（6名男性，4名女性，年龄24 - 65岁）的姿势平衡进行测量。前后（AP）和左右（ML）身体摆动的反馈来自安装在躯干带上的双轴线性加速度计，并显示在贴于舌背前部的144点电触觉阵列上。通过在有和没有GVS的情况下自愿摆动以在舌头上绘制图形，训练受试者使用舌电触觉反馈（TEF）。受试者进行了24次随机试验（闭眼持续20秒，每种条件2次试验），包括4种支撑表面条件（固定、旋转摆动参考、支撑表面与AP摆动成比例平移，以及旋转 - 平移组合支撑平台摆动参考）和3种反馈条件（基线、GVS以及GVS加TEF）。使用相对于直立的偏差（峰峰值和均方根摆动）以及向稳定极限的收敛（到达支撑边界极限的时间和距离）来评估姿势性能。在所有平台条件下，GVS期间姿势稳定性均受损（相对于基线），在旋转摆动参考试验中性能下降更大。电触觉反馈使GVS期间的性能提高至接近非GVS水平，尤其是在旋转摆动参考试验中。这些结果证明了TEF在提供感觉替代以在前庭干扰期间维持姿势稳定性方面的有效性。
