A neural mechanism for affective well-being: Subgenual cingulate cortex mediates real-life effects of nonexercise activity on energy

Abstract

Physical activity substantially improves well-being and mental health, but the underlying brain processes remain unclear. Most research concerns exercise, although the majority of everyday human behaviors, such as walking or stair climbing, are nonexercise activities. Combining neuroimaging with ecological assessment of activity and GPS-triggered smartphone diaries, we show a specific association of nonexercise activity with energy in two independent samples mediated by the subgenual part of the anterior cingulate cortex (sgACC), a key emotion regulatory site. Furthermore, energy predicted a range of mental health metrics. sgACC volume moderated humans' emotional gain from nonexercise activity in real life: Individuals with low sgACC volume, a risk factor for depression, felt less energized when inactive but benefited more from periods of high nonexercise activity. This suggests an everyday life mechanism affecting affective well-being in the general population and, if substantiated in patient samples, a risk and resilience process for mood disorders.

Fig. 1. The total amount of nonexercise activity within the study week relates to gray matter volume of the subgenual ACC.

(A) T map of the significant association between mean nonexercise activity across the study week and gray matter volume. For illustration purposes, findings are shown at a significance threshold of P < 0.005, uncorrected. (B) Scatterplot of the association between mean nonexercise activity across the study week [x axis; depicted are group-centered Movement Acceleration Intensity values (for details, see Methods), residualized for age, gender, total intracranial volume (TIV), BMI, and total exercise activity across the study week) and subgenual ACC gray matter volume [y axis; depicted are individual gray matter volume values for the peak voxel as defined by the main ROI analysis as shown in (A), residualized for age, gender, TIV, BMI, and total exercise activity across the study week]. a.u., arbitrary units.

Fig. 2. sgACC volume moderates the within-subject association between nonexercise activity and energetic arousal.

Here, the estimated within-person effects of nonexercise activity (x axis) on energy (y axis) within the study participant showing the lowest (solid regression line) versus within the participant demonstrating the highest sgACC volume (dashed regression line) from the multilevel model are displayed. Please note that nonexercise values to the left of the x axis refer to sedentary behavior such as sitting, while nonexercise values to the right depict moderate activities such as walking in everyday life.