Department of Psychiatry, University of Western Ontario, London, Ontario, Canada.
Neuroimage. 2013 Jan 15;65:324-35. doi: 10.1016/j.neuroimage.2012.09.046. Epub 2012 Sep 26.
Neurofeedback (NFB) involves a brain-computer interface that allows users to learn to voluntarily control their cortical oscillations, reflected in the electroencephalogram (EEG). Although NFB is being pioneered as a noninvasive tool for treating brain disorders, there is insufficient evidence on the mechanism of its impact on brain function. Furthermore, the dominant rhythm of the human brain is the alpha oscillation (8-12 Hz), yet its behavioral significance remains multifaceted and largely correlative. In this study with 34 healthy participants, we examined whether during the performance of an attentional task, the functional connectivity of distinct fMRI networks would be plastically altered after a 30-min session of voluntary reduction of alpha rhythm (n=17) versus a sham-feedback condition (n=17). We reveal that compared to sham-feedback, NFB induced an increase of connectivity within regions of the salience network involved in intrinsic alertness (dorsal anterior cingulate), which was detectable 30 min after termination of training. The increase in salience network (default-mode network) connectivity was negatively (positively) correlated with changes in 'on task' mind-wandering as well as resting state alpha rhythm. Crucially, we observed a causal dependence between alpha rhythm synchronization during NFB and its subsequent change at resting state, not exhibited by the SHAM group. Our findings provide neurobehavioral evidence for the brain's exquisite functional plasticity, and for a temporally direct impact of NFB on a key cognitive control network, suggesting a promising basis for its use to treat cognitive disorders under physiological conditions.
神经反馈（NFB）涉及一种脑机接口，允许用户学习自愿控制皮质振荡，这些振荡反映在脑电图（EEG）中。尽管 NFB 作为一种治疗大脑疾病的非侵入性工具正在被开拓，但它对大脑功能的影响机制的证据还不够充分。此外，人类大脑的主导节律是阿尔法振荡（8-12Hz），但其行为意义仍然是多方面的，并且在很大程度上是相关的。在这项有 34 名健康参与者的研究中，我们检查了在执行注意力任务时，经过 30 分钟的自愿减少阿尔法节律（n=17）与假反馈条件（n=17）的 session 后，不同 fMRI 网络的功能连接是否会发生塑性变化。我们发现，与假反馈相比，NFB 会增加与内在警觉（背侧前扣带）相关的显着网络区域内的连接，这在训练结束后 30 分钟即可检测到。显着网络（默认模式网络）连接的增加与“任务中”思维漫游以及静息状态阿尔法节律的变化呈负相关（正相关）。至关重要的是，我们观察到 NFB 期间的阿尔法节律同步与其在静息状态下随后的变化之间存在因果关系，而假反馈组则没有表现出这种关系。我们的研究结果为大脑的高度功能可塑性以及 NFB 对关键认知控制网络的即时影响提供了神经行为证据，这为在生理条件下使用 NFB 治疗认知障碍提供了有希望的基础。
