Freyer Frank, Reinacher Matthias, Nolte Guido, Dinse Hubert R, Ritter Petra
Bernstein Focus State Dependencies of Learning and Bernstein Center for Computational Neuroscience Berlin, Germany.
Front Hum Neurosci. 2012 May 23;6:144. doi: 10.3389/fnhum.2012.00144. eCollection 2012.
Neurological disorders and physiological aging can lead to a decline of perceptual abilities. In contrast to the conventional therapeutic approach that comprises intensive training and practicing, passive repetitive sensory stimulation (RSS) has recently gained increasing attention as an alternative to countervail the sensory decline by improving perceptual abilities without the need of active participation. A particularly effective type of high-frequency RSS, utilizing Hebbian learning principles, improves perceptual acuity as well as sensorimotor functions and has been successfully applied to treat chronic stroke patients and elderly subjects. High-frequency RSS has been shown to induce plastic changes of somatosensory cortex such as representational map reorganization, but its impact on the brain's ongoing network activity and resting-state functional connectivity has not been investigated so far. Here, we applied high-frequency RSS in healthy human subjects and analyzed resting state Electroencephalography (EEG) functional connectivity patterns before and after RSS by means of imaginary coherency (ImCoh), a frequency-specific connectivity measure which is known to reduce over-estimation biases due to volume conduction and common reference. Thirty minutes of passive high-frequency RSS lead to significant ImCoh-changes of the resting state mu-rhythm in the individual upper alpha frequency band within distributed sensory and motor cortical areas. These stimulation induced distributed functional connectivity changes likely underlie the previously observed improvement in sensorimotor integration.
神经障碍和生理衰老会导致感知能力下降。与包括强化训练和练习的传统治疗方法不同，被动重复感觉刺激（RSS）作为一种替代方法最近受到越来越多的关注，它无需主动参与，而是通过提高感知能力来抵消感觉衰退。一种特别有效的高频RSS利用赫布学习原理，可提高感知敏锐度以及感觉运动功能，并已成功应用于治疗慢性中风患者和老年受试者。高频RSS已被证明可诱发体感皮层的可塑性变化，如表征图重组，但到目前为止，其对大脑正在进行的网络活动和静息态功能连接的影响尚未得到研究。在这里，我们对健康人类受试者应用高频RSS，并通过想象相干性（ImCoh）分析RSS前后的静息态脑电图（EEG）功能连接模式，ImCoh是一种频率特异性连接测量方法，已知可减少由于容积传导和公共参考导致的高估偏差。30分钟的被动高频RSS导致在分布式感觉和运动皮层区域内的个体上α频段静息态μ节律的ImCoh发生显著变化。这些刺激诱导的分布式功能连接变化可能是先前观察到的感觉运动整合改善的基础。
