Objectives
Various active control interventions for Mindfulness-Based Stress Reduction (MBSR) have been developed, though many can fall short in controlling for non-specific or placebo effects. We developed a Nature-Based Stress Reduction (NBSR) program based on previously reported positive results from virtual natural environment exposure on mental health.
Methods
In the present study, we present the NBSR program with its components that were matched with MBSR to ensure equality in structure, duration, contacts, and intensity, but not in specific active components (i.e., mindfulness meditation). Furthermore, we characterized the nature video component of NBSR (videos consisting of scenes of nature) as an attention-matched activity equivalent to the formal meditation practice components of MBSR. Videos were edited with creator permissions and freely online available content to include ten 3-min clips for scenes of nature from 8 different biomes. All clips were viewed by 3 different staff members and rated based on hedonic valence (pleasant to unpleasant). Each 30-min video set was designed to have a ratio of 4 pleasant, 3 unpleasant, and 3 neutral valence clips consistent with the documented heterogeneity of affective experiences during mindfulness meditation. Amazon Mechanical Turk Workers (n = 127) rated hedonic valence and self-reported arousal for individual video clips. We conducted ANOVA and t-tests to establish how hedonic valence differed by proposed valence category.
Results
Mean valence ratings significantly differed between the three categories of nature video clips using an ANOVA test (p < .001). Follow-up pairwise t-tests revealed significant differences between valence ratings for pleasant vs. unpleasant (p < .001), neutral vs. unpleasant (p < .001), and pleasant vs. neutral (p < .01).
Conclusions
The subjective experience of NBSR nature videos was reported as pleasant, with higher variability reported for unpleasant clips. This pattern generally parallels the variability and heterogeneity of subjective experiences during mindfulness meditation. These findings demonstrate that the nature video component of NBSR provides promising attention- and valence-matched placebo activity unrelated to mindfulness meditation. A comparison of NBSR versus MBSR in a randomized controlled trial is needed to validate NBSR; however, the freely available nature videos may be a useful component to match mindfulness meditation practice in studies.