Autonomic regulation during cognitive reappraisal in major depressive disorder: a study of fMRI correlates

Emotion regulation mediated by cognitive reappraisal can induce activity changes in brain areas and fluctuations in peripheral physiological indicators regulated by the autonomic nervous system (ANS). However, little is known about the relationship between emotional and ANS regulation in major depressive disorder (MDD). In specific, the intermediate band (IM; 0.12–0.18 Hz) is thought to reflect relaxation and emotion processing. In a real-time fMRI neurofeedback-guided cognitive reappraisal experiment in MDD patients, we utilized a general linear model to obtain brain activations of reappraisal, heart rate variability (HRV) IM band, and respiratory IM band. The emotion regulation-related brain regions involved in cognitive reappraisal were defined as regions of interest (ROIs). Statistical tests were performed on the average time course of voxels within these ROIs in the brain activations of HRV and respiratory IM band. This enabled the establishment of the coupling between brain regions involved in emotion regulation and peripheral physiological indicators. Emotion regulation and fluctuations in the IM band of HRV and respiration during cognitive reappraisal predicted brain activity, both for MDD patients and healthy controls. However, there were significant differences between patients and healthy controls in the coupling between ANS activity and neural activity during emotion regulation. In particular, the coupling between the IM band and prefrontal regions changed over training sessions only in MDD patients. This study established links between peripheral physiological indicators in the IM band and neural activity that deepen understanding of ANS regulation in MDD patients. The identified altered ANS coupling and its relation to cognitive reappraisal emphasize the close association between the IM band and emotion regulation, which may aid in assessing psychological states in patients with MDD.