Human Aerospace Laboratory, Department of Neurology, Mount Sinai School of Medicine, 1 Gustave L Levy Place, Box 1052, New York, NY 10029, USA.
Exp Brain Res. 2012 Jan;216(2):275-85. doi: 10.1007/s00221-011-2929-z. Epub 2011 Nov 11.
Although imaging studies suggest activation of cortical areas by vestibular input, there is little evidence of an adverse effect of non-veridical vestibular input on cognitive function. To test the hypothesis that degraded vestibular afferent input adversely affects cognition, we compared performance on a cognitive test battery in a group undergoing suprathreshold bilateral bipolar Galvanic vestibular stimulation (GVS) with a control group receiving no GVS or subthreshold stimulation. The battery consisted of six cognitive tests as follows: reaction time, dual tasking, Stroop, mental rotation, perspective-taking and matching-to-sample, as well as a simple visuomotor (manual tracking) task. Subjects performed the test battery before, during and after suprathreshold GVS exposure or subthreshold stimulation. Suprathreshold GVS significantly increased error rate for the match-to-sample and perspective-taking tasks relative to the subthreshold group, demonstrating a negative effect of non-veridical vestibular input in these specific cognitive tasks. Reaction time, dual tasking, mental rotation and manual tracking were unaffected by GVS exposure. The adverse effect of suprathreshold GVS on perspective taking but not mental rotation is consistent with imaging studies, which have demonstrated that egocentric mental transformations (perspective taking) occur primarily in cortical areas that receive vestibular input (the parietal-temporal junction and superior parietal lobule), whereas object-based transformations (mental rotation) occur in the frontoparietal region. The increased error rate during the match-to-sample task is likely due to interference with hippocampal processing related to spatial memory, as suggested by imaging studies on vestibular patients.
尽管影像学研究表明前庭输入会激活皮质区域，但几乎没有证据表明非真实前庭输入会对认知功能产生不良影响。为了验证退化的前庭传入输入会对认知产生不利影响的假设，我们比较了一组接受阈上双侧双极电刺激（GVS）的人群和一组未接受 GVS 或阈下刺激的对照组在认知测试组上的表现。该测试组由以下六个认知测试组成：反应时间、双重任务、Stroop、心理旋转、换位思考和匹配样本，以及简单的视觉运动（手动跟踪）任务。在阈上 GVS 暴露或阈下刺激之前、期间和之后，受试者都要进行测试组。与阈下组相比，阈上 GVS 显著增加了匹配样本和换位思考任务的错误率，表明非真实前庭输入对这些特定认知任务有负面影响。反应时间、双重任务、心理旋转和手动跟踪不受 GVS 暴露的影响。阈上 GVS 对换位思考的负面影响而不是心理旋转的影响与影像学研究一致，影像学研究表明，自我中心的心理转换（换位思考）主要发生在前庭输入的皮质区域（顶颞交界处和上顶叶），而基于对象的转换（心理旋转）发生在前顶叶区域。匹配样本任务期间错误率的增加可能是由于与空间记忆相关的海马处理受到干扰，这与前庭患者的影像学研究结果一致。
