Man Vehicle Laboratory, Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA; Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA, 02114, USA.
Man Vehicle Laboratory, Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA; Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA, 02114, USA; Smead Aerospace Engineering Sciences, 429 UCB University of Colorado, Boulder, CO, USA.
Brain Stimul. 2018 Jul-Aug;11(4):716-722. doi: 10.1016/j.brs.2018.03.017. Epub 2018 Apr 3.
Stochastic Resonance (SR) is a phenomenon broadly described as "noise benefit". The application of subsensory electrical Stochastic Vestibular Stimulation (SVS) via electrodes behind each ear has been used to improve human balance and gait, but its effect on motion perception thresholds has not been examined.
This study investigated the capability of subsensory SVS to reduce vestibular motion perception thresholds in a manner consistent with a characteristic bell-shaped SR curve.
We measured upright, head-centered, roll tilt Direction Recognition (DR) thresholds in the dark in 12 human subjects with the application of wideband 0-30 Hz SVS ranging from ±0-700 μA. To conservatively assess if SR was exhibited, we compared the proportions of both subjective and statistical SR exhibition in our experimental data to proportions of SR exhibition in multiple simulation cases with varying underlying SR behavior. Analysis included individual and group statistics.
As there is not an established mathematical definition, three humans subjectively judged that SR was exhibited in 78% of subjects. "Statistically significant SR exhibition", which additionally required that a subject's DR threshold with SVS be significantly lower than baseline (no SVS), was present in 50% of subjects. Both percentages were higher than simulations suggested could occur simply by chance. For SR exhibitors, defined by subjective or statistically significant criteria, the mean DR threshold improved by -30% and -39%, respectively. The largest individual improvement was -47%.
At least half of the subjects were better able to perceive passive body motion with the application of subsensory SVS. This study presents the first conclusive demonstration of SR in vestibular motion perception.
随机共振（SR）是一种被广泛描述为“噪声受益”的现象。通过在每只耳朵后面的电极施加亚感觉电随机前庭刺激（SVS）已被用于改善人类平衡和步态，但它对运动感知阈值的影响尚未被检查。
本研究旨在调查亚感觉 SVS 降低前庭运动感知阈值的能力，其方式与特征性钟形 SR 曲线一致。
我们在 12 名人类受试者中测量了黑暗中直立、头中心的滚转角方向识别（DR）阈值，同时应用了 0-30Hz 的宽带 SVS，范围为±0-700µA。为了保守地评估是否表现出 SR，我们将实验数据中主观和统计 SR 表现的比例与具有不同潜在 SR 行为的多个模拟案例中的 SR 表现比例进行了比较。分析包括个体和组统计。
由于没有既定的数学定义，三名人类受试者主观判断 78%的受试者表现出 SR。“具有统计学意义的 SR 表现”，这还要求受试者的 SVS 下 DR 阈值明显低于基线（无 SVS），在 50%的受试者中存在。这两个百分比都高于模拟表明仅因机会而发生的百分比。对于通过主观或统计学显著标准定义的 SR 受试者，DR 阈值分别改善了-30%和-39%。最大的个体改善为-47%。
至少有一半的受试者在应用亚感觉 SVS 时能够更好地感知被动身体运动。本研究首次在前庭运动感知中证明了 SR 的存在。
