Expectation and the vestibular control of balance
Expectation and the vestibular control of balance
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DOI：
10.1162/0898929053279540
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发表时间：
2005-03-01
影响因子：
3.2
通讯作者：
Day, BL
中科院分区：
文献类型：
--
作者：
Guerraz, M;Day, BL
最近的实验表明，平衡控制的视觉通道易受认知影响。当受试者意识到即将到来的视觉障碍可能来自外部因素，即视觉环境的移动，而不是来自自我运动时，全身反应被抑制。在这里，我们问这是否是一个原则，推广到前庭通道的平衡控制。我们研究了全身对前庭电刺激（GVS; 0.5mA，持续3秒）产生的纯前庭扰动的反应。在第一个实验中，受试者站着，视觉被遮挡，同时刺激由受试者自己（自我触发）或由实验者提供。对于后者，刺激要么没有警告（不可预测），要么在一个固定的时间间隔后，听觉crue（可预测）。结果表明，GVS引起的全身反应不受刺激是否是自我触发的，可预测的，或不可预测的。在第二个实验中也得到了同样的结果，在这个实验中，受试者在前庭刺激期间获得了视觉信息。我们的结论是前庭诱发的平衡反应是自动的和免疫知识的扰动源和它的时间。我们认为，视觉和前庭通道之间的这种差异的原因是源于他们的自然能力的差异，以信号的自我运动。前庭系统对头部在空间中的加速度做出反应，因此总是发出自我运动的信号。另一方面，视觉流是模糊的，因为它发出物体运动和眼睛运动的信号，以及自我运动。
Recent experiments have shown that the visual channel Of balance control is susceptible to cognitive influence. When a subject is aware that an upcoming visual disturbance is likely to arise from an external agent, that is, movement of the Visual environment, rather than from self-motion, the whole-body response is suppressed. Here we ask whether this is a principle that generalizes to the vestibular channel of balance control. We Studied the whole-body response to a pure Vestibular perturbation produced by galvanic vestibular stimulation (GVS; 0.5 mA for 3 sec). In the first experiment, subjects stood with vision occluded while stimuli were delivered either by the subject himself (self-triggered) or by the experimenter. For the latter, the stimulus was delivered either without warning (unpredictable) or at a fixed interval following an auditory crue (predictable). Results showed that GVS evoked a whole-body response that was not affected by whether the stimulus was self-triggered, predictable, or unpredictable. The same results were obtained in a second experiment in which subjects had access to visual information during vestibular stimulation. We conclude that the vestibular-evoked balance response is automatic and immune to knowledge of the source of the perturbation and its timing. We suggest the reason for this difference between visual and vestibular channels stems from a difference in their natural abilities to signal self-motion. The vestibular system responds to acceleration of the head in space and therefore always signals self-motion. Visual flow, on the other hand, is ambiguous in that it signals object motion and eye motion, as well as self-motion.