Facing emotions: real-time fMRI-based neurofeedback using dynamic emotional faces to modulate amygdala activity

Introduction: Maladaptive functioning of the amygdala has been associated with impaired emotion regulation in affective disorders. Recent advances in real-time fMRI neurofeedback have successfully demonstrated the modulation of amygdala activity in healthy and psychiatric populations. In contrast to an abstract feedback representation applied in standard neurofeedback designs, we proposed a novel neurofeedback paradigm using naturalistic stimuli like human emotional faces as the feedback display where change in the facial expression intensity (from neutral to happy or from fearful to neutral) was coupled with the participant's ongoing bilateral amygdala activity. Methods: The feasibility of this experimental approach was tested on 64 healthy participants who completed a single training session with four neurofeedback runs. Participants were assigned to one of the four experimental groups (n = 16 per group), i.e., happy-up, happy-down, fear-up, fear-down. Depending on the group assignment, they were either instructed to "try to make the face happier" by upregulating (happy-up) or downregulating (happy-down) the amygdala or to "try to make the face less fearful" by upregulating (fear-up) or downregulating (fear-down) the amygdala feedback signal. Results: Linear mixed effect analyses revealed significant amygdala activity changes in the fear condition, specifically in the fear-down group with significant amygdala downregulation in the last two neurofeedback runs as compared to the first run. The happy-up and happy-down groups did not show significant amygdala activity changes over four runs. We did not observe significant improvement in the questionnaire scores and subsequent behavior. Furthermore, task-dependent effective connectivity changes between the amygdala, fusiform face area (FFA), and the medial orbitofrontal cortex (mOFC) were examined using dynamic causal modeling. The effective connectivity between FFA and the amygdala was significantly increased in the happy-up group (facilitatory effect) and decreased in the fear-down group. Notably, the amygdala was downregulated through an inhibitory mechanism mediated by mOFC during the first training run. Discussion: In this feasibility study, we intended to address key neurofeedback processes like naturalistic facial stimuli, participant engagement in the task, bidirectional regulation, task congruence, and their influence on learning success. It demonstrated that such a versatile emotional face feedback paradigm can be tailored to target biased emotion processing in affective disorders

Improving emotion regulation in depression using real-time fMRI-based neurofeedback

Major depressive disorders (MDD), commonly known as depression, have a high prevalence worldwide. Patients suffering from depression have deficits in emotion-processing brain regions and networks. This highlights emotional biases in depression patients, as patients show selective or enhanced brain reactions to negative emotions, while the processing of positive emotions is reduced. Modern neuroimaging methods such as real-time fMRI-based neurofeedback can help patients self-regulate their dysfunctional brain regions by presenting them with feedback on their own brain activity. By modulating brain responses through appropriate cognitive strategies, patients can improve their emotion regulation skills. Based on these findings, we aimed to address positive and negative emotional biases in depression. In this experimental MRI-based intervention, patients are shown faces with different emotions ranging from fearful to happy. They are asked to make neutral faces more happy by actively using positive strategies while decreasing facial fearfulness to reduce anxiety symptoms. This approach serves as a therapeutic measure by allowing patients to learn to control their dysfunctional brain activity. It is non-invasive and has no major side effects, hence it is safe. Most importantly, it focuses on a fundamental human trait, our ability to learn. This study aims to evaluate the effectiveness of such an innovative neurofeedback modality in improving the symptoms associated with depression