Recent studies have reported on the feasibility of real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback (NF) training. Although modulation of blood oxygenation level-dependent signal of single brain regions in rt-fMRI NF is a well established technique, the same does not hold true for modulation of connectivity. Self-modulation of interregional connectivity is a potential alternative in clinical neuroscience applications, since long-range functional dysconnectivity is being increasingly recognized as a mechanism underlying neuropsychiatric disorders. In this study, a framework was designed to train participants to self-regulate, in real time, interhemispheric functional connectivity between bilateral premotor cortices. To this end, participants use a novel adaptive motor imagery task, with gradual frequency variation preventing activity plateaus and subsequent decreases in correlation of activity (three NF runs). Participants were able to upregulate and maintain interhemispheric connectivity using such adaptive approach, as measured by correlation analysis. Modulation was achieved by simultaneous volitional control of activity in premotor areas. Activation patterns in the downregulation condition led to significantly lower correlation values than those observed in the upregulation condition, in the first two NF runs. Comparison between runs with and without feedback showed enhanced activation in key reward, executive function, and cognitive control regions, suggesting NF promotes reward and the development of goal-directed behavior. This proof-of-principle study suggests that functional connectivity feedback can be used for volitional self-modulation of neuronal connectivity. Functional connectivity-based NF could serve as a possible therapeutic tool in diseases related to the impairment of interhemispheric connectivity, particularly in the context to motor training after stroke.

中文翻译：

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使用自适应方法在实时功能磁共振成像神经反馈研究中对运动前皮层半球之间连通性的自调制。

最近的研究报告了实时功能磁共振成像（rt-fMRI）神经反馈（NF）训练的可行性。尽管在rt-fMRI NF中调节单个大脑区域的血液氧合水平依赖性信号是一项公认的技术，但对于调节连通性却不成立。区域间连通性的自我调节是临床神经科学应用中的一种潜在替代方法，因为远程功能性失连通性已被越来越多地视为神经精神疾病的潜在机制。在这项研究中，设计了一个框架来训练参与者实时调节双侧运动前皮质之间的半球功能连通性。为此，参与者使用新颖的自适应运动图像任务，频率逐渐变化会阻止活动平台并随后降低活动相关性（三个NF运行）。通过相关分析，参与者能够使用这种自适应方法来上调和维持半球之间的连通性。通过同时自愿控制运动前区域的活动来实现调节。在前两个NF运行中，下调条件下的激活模式导致的相关值明显低于上调条件下的相关值。有和没有反馈的跑步之间的比较表明，关键奖励，执行功能和认知控制区域的激活增强，表明NF促进奖励和目标导向行为的发展。这项原理证明研究表明，功能连接反馈可用于神经元连接的自愿自我调节。基于功能连接性的神经纤维蛋白可以作为与半球间连接性受损有关的疾病的一种可能的治疗工具，尤其是在卒中后运动训练的背景下。