Hans Berger Department for Neurology, University Hospital Jena, Germany.
Clinic for Otorhinolaryngology, University Hospital Jena, Germany.
Behav Brain Res. 2013 Jan 1;236(1):194-199. doi: 10.1016/j.bbr.2012.08.049. Epub 2012 Sep 6.
It is known that the functional response (e.g., nystagmus) to caloric vestibular stimulation is delayed and prolonged compared with the stimulus-response timing of other sensory systems. Imaging studies have used different models to predict cortical responses and to determine the areas of the brain that are involved. These studies have revealed a widespread network of vestibular brain regions. However, there is some disagreement regarding the brain areas involved, which may partly be caused by differences in the models used. This disagreement indicates the possible existence of multiple cortical components with different temporal characteristics that underlie cortical vestibular processing. However, data-driven methods have yet to be used to analyze the underlying hemodynamic components during and after vestibular stimulation. We performed functional magnetic resonance imaging (fMRI) on 12 healthy subjects during caloric stimulation and analyzed these data using a model-free analysis method (ICA). We found seven independent stimulus-induced components that outline a robust pattern of cortical activation and deactivation. These independent components demonstrated significant differences in their time courses. No single-modeled response function was able to cover the entire range of these independent components. The response functions determined in the present study should improve model-based studies investigating vestibular cortical processing.
已知与其他感觉系统的刺激-反应时相比，冷热前庭刺激的功能反应（如眼震）延迟且持续时间更长。影像学研究使用不同的模型来预测皮质反应，并确定参与的脑区。这些研究揭示了广泛的前庭脑区网络。然而，关于涉及的脑区存在一些分歧，这可能部分是由于使用的模型不同所致。这种分歧表明，皮质前庭处理可能存在多个具有不同时间特征的皮质成分。然而，在冷热前庭刺激期间和之后，还没有使用数据驱动的方法来分析潜在的血液动力学成分。我们在 12 名健康受试者进行冷热刺激期间进行了功能磁共振成像（fMRI），并使用无模型分析方法（ICA）对这些数据进行了分析。我们发现了七个独立的刺激诱导成分，这些成分勾勒出了皮质激活和失活的稳健模式。这些独立成分的时程表现出显著差异。没有单一建模的响应函数能够涵盖这些独立成分的整个范围。本研究中确定的响应函数应改善基于模型的前庭皮质处理研究。
