University of Colorado Boulder (Smead Aerospace Engineering Sciences), Boulder, Co, USA.
Soterix Medical, Inc, Woodbridge, NJ, USA.
Exp Brain Res. 2024 Oct;242(10):2443-2455. doi: 10.1007/s00221-024-06908-6. Epub 2024 Aug 20.
Galvanic Vestibular Stimulation (GVS) has been proposed as an alternative display modality to relay information without increasing demands on the visual or auditory sensory modalities of the wearer or in environments where those modalities cannot be used (e.g., covert night operations). We further investigated this concept with four experiments designed to test: (1) thresholds at which subjects could distinguish between different GVS current amplitudes and polarities, (2) thresholds at which different bipolar (i.e., sinusoidal waveform with current oscillating between left and right directions) current frequencies were distinguishable among room temperature, hot, cold, and windy environments, (3) effects of unipolar (i.e., sinusoidal waveform with current occurring in only the left or right direction) currents on balance performance, and (4) dual-task performance among frequency and polarity modulated GVS conditions during a concordant visual search task. Subjects reliably distinguished between current amplitudes that varied from a pedestal of ± 0.6 mA by a median of 0.03 mA (range of 0.02-0.32 mA) and between unipolar currents at a median amplitude of 0.55 mA (range of 0.32-0.83 mA). GVS frequency thresholds were robust to the environment conditions tested, with no statistical differences found. Sway and balance errors were increased with unipolar currents. GVS thresholds were not impacted by the dual-task paradigm, but the visual search scores were slightly elevated when congruently performing a polarity thresholding task. Overall findings continue to support GVS use as a display modality, but some limitations are noted, such as the use of unipolar currents under scenarios where postural control is important.
电刺激前庭（GVS）已被提议作为一种替代显示模式，用于在不增加佩戴者视觉或听觉感官模式需求的情况下传递信息，或者在无法使用这些模式的环境中（例如，秘密夜间行动）。我们进一步通过四个实验来研究这一概念，旨在测试：（1）被试者能够区分不同 GVS 电流幅度和极性的阈值，（2）不同双极（即电流在左右方向之间振荡的正弦波）电流频率在室温、热、冷和风环境中可区分的阈值，（3）单极（即仅在左或右方向发生电流的正弦波）电流对平衡性能的影响，以及（4）在一致的视觉搜索任务中，在频率和极性调制 GVS 条件下进行双重任务的表现。被试者可靠地区分了电流幅度，范围从±0.6 mA 的基准值变化了 0.03 mA（范围为 0.02-0.32 mA），并且可靠地区分了单极电流，其幅度中位数为 0.55 mA（范围为 0.32-0.83 mA）。GVS 频率阈值对所测试的环境条件具有稳健性，没有发现统计学差异。单极电流会增加摆动和平衡误差。GVS 阈值不受双重任务范式的影响，但在执行一致的极性阈值任务时，视觉搜索得分略有升高。总体研究结果继续支持 GVS 作为一种显示模式，但也注意到了一些限制，例如在需要姿势控制的情况下使用单极电流。
