Probing fMRI brain connectivity and activity changes during emotion regulation by EEG neurofeedback

Neurofeedback is a non-invasive brain training with long-term medical and non-medical applications. Despite the existence of several emotion regulation studies using neurofeedback, further investigation is needed to understand interactions of the brain regions involved in the process. We implemented EEG neurofeedback with simultaneous fMRI using a modified happiness-inducing task through autobiographical memories to upregulate positive emotion. The results showed increased activity of prefrontal, occipital, parietal, and limbic regions and increased functional connectivity between prefrontal, parietal, limbic system, and insula in the experimental group. New connectivity links were identified by comparing the functional connectivity of different experimental conditions within the experimental group and between the experimental and control groups. The proposed multimodal approach quantified the changes in the brain activity (up to 1.9% increase) and connectivity (FDR-corrected for multiple comparison, q = 0.05) during emotion regulation in/between prefrontal, parietal, limbic, and insula regions. Psychometric assessments confirmed significant changes in positive and negative mood states by neurofeedback with a p-value smaller than 0.002 in the experimental group. This study quantifies the effects of EEG neurofeedback in changing functional connectivity of all brain regions involved in emotion regulation. For the brain regions involved in emotion regulation, we found significant BOLD and functional connectivity increases due to neurofeedback in the experimental group but no learning effect was observed in the control group. The results reveal the neurobiological substrate of emotion regulation by the EEG neurofeedback and separate the effect of the neurofeedback and the recall of the autobiographical memories.