正弦电流前庭刺激对认知负荷期间心血管反应极性依赖性影响

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中文摘要

前庭系统在重力负荷变化（如体位转换、微重力）、前庭疾病以及前庭刺激期间参与心血管调节。采用正弦电流前庭刺激（GVS）的研究报告了相互矛盾的自主神经反应，近期证据提示前庭传入以非线性方式编码GVS。这种非线性编码是否导致极性依赖的自主神经反应，以及这些反应是否与同时存在的认知需求相互作用，尚不清楚。为探讨这些问题，我们对35名健康个体使用正弦GVS调节前庭输入，同时使用可穿戴设备记录生理信号。参与者在三种平衡条件下完成工作记忆任务，任务前后各有休息期：右侧阳极/左侧阴极GVS（RGVS）、左侧阳极/右侧阴极GVS（LGVS）和假GVS。反复评估感知压力。任务执行期间，与假GVS相比，RGVS使心率增加，LGVS使心率降低（p = 0.001），所有条件下感知压力均增加（p < 0.001）。任务后，RGVS的心率仍高于LGVS（p = 0.006），LGVS的压力评分较其他条件降低（p < 0.01）。这些发现表明，正弦GVS诱导极性依赖的自主神经效应，主要发生在同时存在认知需求时。这种模式可能反映非线性前庭编码，其出现可能受注意力转移的调节。

英文摘要

The vestibular system contributes to cardiovascular regulation during changes in gravitational load (e.g., postural transitions, microgravity), in vestibular disorders, and during vestibular stimulations. Studies employing sinusoidal galvanic vestibular stimulation (GVS) reported conflicting autonomic responses, and recent evidence suggests that vestibular afferents encode GVS in a non-linear fashion. Whether this non-linear encoding results in polarity-dependent autonomic responses and whether such responses interact with concurrent cognitive demand remains unknown. To investigate these issues, we used sinusoidal GVS to modulate vestibular input in 35 healthy individuals while physiological signals were recorded using a wearable device. Participants completed a working memory task, preceded and followed by rest periods, under three counterbalanced conditions: right-anodal/left-cathodal GVS (RGVS), left-anodal/right-cathodal GVS (LGVS), and Sham GVS. Perceived stress was repeatedly assessed. During task performance, heart rate increased with RGVS and decreased with LGVS relative to Sham (p = 0.001) and perceived stress increased across all conditions (p < 0.001). Post-task, heart rate remained elevated in RGVS compared to LGVS (p = 0.006), and stress ratings decreased in LGVS compared to the other conditions (p < 0.01). These findings indicate that sinusoidal GVS induces polarity-dependent autonomic effects, primarily during concurrent cognitive demand. This pattern may reflect non-linear vestibular encoding, with its emergence being potentially modulated by attentional shifts.