How does nature influence the brain, body and mind?

Recent meta-analyses have suggested that nature appears to improve cognition (Ohly et al., 2016; Stevensen et al., 2018). These analyses revealed that there are strong improvements in working memory and cognitive flexibility, and somewhat weaker improvements in attentional inhibition. In other words, there appear to be improvements in all three of the core “executive functions” (i.e. Diamond, 2013; Miyake et al., 2000) –the functions considered vital to achieving almost any goal-directed behavior. There is also evidence that nature reduces stress. For example, recent meta-analyses have shown that blood pressure decreases in nature (Ideno et al., 2017), and that vagally-mediated heart-rate variability, a marker of the body’s parasympathetic “rest and digest” system, increases in nature (Cheng et al., 2021). However, questions still remain about the exact mechanisms by which these changes emerge.

Our past research on this topic:

Attention Restoration Theory suggests that volitional attention is restored when participants spend time in nature—we aim to understand whether this hypothesis is supported by neurophysiological evidence. We accomplished this by taking participants on a 5-day camping trip and recording their brain activity before, during and after the trip. In our first study, we found neurological evidence that participants, when instructed to sit for ten minutes, are more visually engaged with their surroundings while in nature (Hopman et al., 2020). Although this provided evidence for changed baseline brain activity, it was still unclear whether or not brain activity would change, or be restored, for attentionally demanding tasks. Therefore, we next examined how the Error-Related Negativity (ERN), a brain wave related to cognitive control, might change in response to nature compared to a lab (LoTemplio et al., 2020)—our findings suggested a boost in cognitive control abilities while participants are in nature, as manifested by an increase in ERN amplitude. In addition to this work, we have documented neural changes in both reward processing (McDonnell et al., under review, and attentional processes (Scott et al., under review) in nature. In addition to EEG, we have also documented how physiological measures of stress (e.g. heart- rate variability) change in nature (Scott et al., 2020), in response to longer-term nature exposure. Finally, we recently authored an integrative review and novel framework on psychophysiological changes in nature (Scott et al., 2021).

Current Research Questions:

1. Can the neurophysiological changes in nature be linked via a single biomarker of midline frontal theta? Midline frontal theta is a broad oscillatory signal in the EEG that is thought to subsume many cognitive control processes such as error-processing, reward processing, and conflict-monitoring. Therefore, understanding changes in theta in nature could be key to uncovering a generalized biomarker for cognitive control changes in nature.
2. To what extent do attention restoration and stress regulation co-occur in nature? However, recently, some have argued that both stress-reduction and attention restoration co-occur, and have argued for the use of simultaneous physiological and cognitive measurement (Scott et al., 2020; 2021). Specifically, Scott et al., (2021) argue that these two processes—stress reduction and attention restoration—co-occur as a direct result of improvement in vagal tone. However, there has been little existing work to test this hypothesis.