Real-time fMRI-based neurofeedback reinforces causality of attention networks.

In this study, we investigated the efficacy of a real-time functional magnetic resonance imaging (rtfMRI)-based neurofeedback method for the modulation of the effective connectivity (EC) of causality between attention-related neuronal activities. In participants who received the feedback of attention-related neuronal activity, the EC estimated from Granger causality analysis was reinforced within the task-related network, such as between the bilateral cingulate gyri and frontal cortices, whereas the EC between the task-related network and task-unrelated resting-state network, including the inferior parietal lobule, was diminished. On the other hand, only marginal changes were observed in participants who received "sham" feedback. This "dynamic" characteristic measure of EC based on causality may be useful for evaluating the efficacy of methods designed to modulate brain networks, including rtfMRI-based neurofeedback.