Frontal Alpha EEG Asymmetry Before and After Positive Psychological Interventions for Medical Students

Subjective well-being (SWB) refers to traits concerned with happiness, fulfillment and enrichment and is a substantial predictor of a flourishing life. Interest in the promotion of well-being has blossomed in recent years, and it is widely reported that positive psychological interventions (PPIs) can effectively improve SWB. However, to date, the neural correlates of PPIs remain elusive. Since previous research has suggested that emotion regulation might be the theoretical foundation for potential working mechanisms, here we used electroencephalography (EEG) techniques to identify whether the intentional increase of subjective well-being through PPIs was associated with greater tonic left frontal activation. Fifty-five students met the inclusion criteria and were allocated to a randomized controlled trial that was single blinded. The intervention group received PPIs once a week for 10 weeks (n = 28). Meanwhile, students in a placebo control group (CG, n = 27) were asked to write down early memories every day for 10 weeks and were invited to share voluntarily at the weekly meeting. Measures of subjective well-being, depression and anxiety were assessed at pre-test and post-test. Forty-eight students completed the post-test, and the collected data were analyzed across time (PPIs, n = 25; CG, n = 23). It was found that students undergoing the 10-week PPIs reported larger improvement in SWB, and greater relief in self-rated depression and anxiety from pre-intervention to post-intervention than did those in the control group. As expected, in conjunction with the promotion of subjective well-being and the amelioration of emotional distress from pre- to post-treatment in the intervention group, a significantly increased coefficient of frontal alpha EEG asymmetry was found. In summary, these findings suggest that adaptive emotion regulation, which is characteristic of greater tonic left frontal activation, reflects the efficiency of PPIs and highlights the frontal alpha EEG asymmetry as a neural substrate linking PPIs and mental health. Clinical Trial Registration Number: ChiCTR-ROC-17012636