Default mode network connectivity contributes the augment effect stress recovery by natural viewing

The psychological benefits of exposure to natural environments are well established. However, whether simply viewing nature images produce similar restorative effects and the brain mechanisms involved remain unclear. For study purposes, we recruited 131 healthy university students and randomly assigned them to a nature image viewing group (NG) or a city image viewing group (CG), with 49 participants further selected (NG = 26, CG = 23) to undergo functional magnetic resonance imaging while performing behavioral tasks. First, we compared changes in subjective ratings and salivary cortisol levels, related to affect and stress between the NG and CG after stress induction and image viewing. Next, we examined differences in functional connectivity (FC) patterns of the default mode network (DMN) between the groups during image viewing. Finally, we explored correlations between the recovery effects observed after viewing nature images, along with alterations in FC. Under stress, NG participants reported greater changes in subjective ratings of positive affect (t = 2.610, p = 0.010), lower negative affect (t = -3.008, p = 0.003), and less state rumination (t = -2.103, p = 0.037). Neural data also suggest that connectivity of the DMN subsystems with attentional and executive regions plays a crucial role in modulating stress-related responses during natural experiences. Increased FC between the medial DMN subsystem and other networks was significantly correlated with behavioral recovery scores for both affect and state rumination. These findings indicate that viewing images of natural scenes can aid in stress recovery, highlighting the potential for indoor nature viewing to help mitigate psychological challenges faced in urban environments.