The psychological benefits of nature exposure and their sensitivity to litter-related environmental degradation: An in situ eye-tracking study

Exposure to natural environments has been associated with the restoration of attentional resources and improvements in affective functioning. Although these psychological benefits are well documented, less is known about whether and how environmental degradation, in the form of litter, attenuates them. In this preregistered study, we investigated the psychological effects of real-world nature exposure and whether these effects were reduced when natural environments were degraded by litter. Participants were exposed, in counterbalanced order, to a preserved forest, a littered forest, and an urban setting. Eye movements, affective state, perceived restorativeness, and mental bandwidth were assessed for each exposure. Compared with the urban setting, the forest settings were associated with lower eye-movement activity (i.e., lower fixation rates and longer fixation durations), more favorable post-exposure affect (i.e., higher positive and lower negative affect, adjusting for pre-exposure levels), and higher perceived restorativeness. The littered forest was associated with higher post-exposure negative affect compared to the preserved forest, whereas no reliable differences emerged for gaze indices, positive affect, or perceived restorativeness. Most mediation analyses were inconclusive regarding the indirect association between environment and affect or perceived restorativeness via eye-movement activity, and attention allocated to litter was neither associated with psychological outcomes nor with nature connectedness or eco-anxiety. Finally, the restorative advantage of natural over urban settings was larger among participants with higher nature connectedness. In the context of increasing urbanization and environmental degradation, these findings highlight the importance of nature preservation for psychological well-being.