Neural Control of Movement Lab, ETH Zürich, Zürich, Switzerland.
Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
Elife. 2018 Nov 29;7:e40843. doi: 10.7554/eLife.40843.
To date there exists no reliable method to non-invasively upregulate or downregulate the state of the resting human motor system over a large dynamic range. Here we show that an operant conditioning paradigm which provides neurofeedback of the size of motor evoked potentials (MEPs) in response to transcranial magnetic stimulation (TMS), enables participants to self-modulate their own brain state. Following training, participants were able to robustly increase (by 83.8%) and decrease (by 30.6%) their MEP amplitudes. This volitional up-versus down-regulation of corticomotor excitability caused an increase of late-cortical disinhibition (LCD), a TMS derived read-out of presynaptic GABA disinhibition, which was accompanied by an increase of gamma and a decrease of alpha oscillations in the trained hemisphere. This approach paves the way for future investigations into how altered brain state influences motor neurophysiology and recovery of function in a neurorehabilitation context.
迄今为止，还没有可靠的方法可以在较大的动态范围内非侵入性地上调或下调静息状态下人类运动系统的状态。在这里，我们展示了一种操作性条件反射范式，该范式提供了针对经颅磁刺激（TMS）的运动诱发电位（MEP）大小的神经反馈，使参与者能够自我调节自己的大脑状态。经过训练，参与者能够强有力地增加（增加 83.8％）和减少（减少 30.6％）他们的 MEP 幅度。这种对皮质运动兴奋性的自主上调与下调导致了晚期皮质抑制（LCD）的增加，这是 TMS 衍生的对前突触 GABA 抑制的读出，同时伴随着训练半球中伽马和阿尔法振荡的增加和减少。这种方法为未来的研究开辟了道路，探讨改变大脑状态如何影响运动神经生理学以及神经康复背景下的功能恢复。
