Fadaee Shannon B, Migliaccio Americo A
Balance and Vision Laboratory, Neuroscience Research Australia, Cnr Barker Street & Easy Street, Randwick, Sydney, 2031, Australia.
University of New South Wales, Sydney, 2031, Australia.
Exp Brain Res. 2016 Apr;234(4):1085-94. doi: 10.1007/s00221-015-4535-y. Epub 2015 Dec 29.
The primary function of the angular vestibulo-ocular reflex (VOR) is to stabilise images on the retina during head movements. Retinal image movement is the likely feedback signal that drives VOR modification/adaptation for different viewing contexts. However, it is not clear whether a retinal image position or velocity error is used primarily as the feedback signal. Recent studies examining this signal are limited because they used near viewing to modify the VOR. However, it is not known whether near viewing drives VOR adaptation or is a pre-programmed contextual cue that modifies the VOR. Our study is based on analysis of the VOR evoked by horizontal head impulses during an established adaptation task. Fourteen human subjects underwent incremental unilateral VOR adaptation training and were tested using the scleral search coil technique over three separate sessions. The update rate of the laser target position (source of the retinal image error signal) used to drive VOR adaptation was different for each session [50 (once every 20 ms), 20 and 15/35 Hz]. Our results show unilateral VOR adaptation occurred at 50 and 20 Hz for both the active (23.0 ± 9.6 and 11.9 ± 9.1% increase on adapting side, respectively) and passive VOR (13.5 ± 14.9, 10.4 ± 12.2%). At 15 Hz, unilateral adaptation no longer occurred in the subject group for both the active and passive VOR, whereas individually, 4/9 subjects tested at 15 Hz had significant adaptation. Our findings suggest that 1-2 retinal image position error signals every 100 ms (i.e. target position update rate 15-20 Hz) are sufficient to drive VOR adaptation.
角前庭眼反射（VOR）的主要功能是在头部运动期间稳定视网膜上的图像。视网膜图像运动可能是驱动VOR针对不同观看情境进行修改/适应的反馈信号。然而，尚不清楚主要是将视网膜图像位置误差还是速度误差用作反馈信号。最近研究该信号的研究有限，因为它们使用近视力来修改VOR。然而，尚不清楚近视力是驱动VOR适应还是一种预先编程的情境线索来修改VOR。我们的研究基于在既定适应任务期间对水平头部冲动诱发的VOR进行分析。14名人类受试者接受了渐进性单侧VOR适应训练，并在三个独立的阶段使用巩膜搜索线圈技术进行测试。用于驱动VOR适应的激光目标位置（视网膜图像误差信号源）的更新速率在每个阶段都不同[50（每20毫秒一次）、20和15/35赫兹]。我们的结果表明，对于主动VOR（适应侧分别增加23.0±9.6和11.9±9.1%）和被动VOR（13.5±14.9、10.4±12.2%），在50和20赫兹时均发生了单侧VOR适应。在15赫兹时，受试者组中主动和被动VOR均不再发生单侧适应，而单独来看，在15赫兹测试的9名受试者中有4名有显著适应。我们的研究结果表明，每100毫秒1 - 2个视网膜图像位置误差信号（即目标位置更新速率15 - （此处原文有误，应为20）20赫兹）足以驱动VOR适应。
