Abstract:
There is a growing body of evidence that demonstrates nature's ability to enhance human health and wellbeing across an expansive range of areas including cognitive, emotional, social, and physical wellbeing. As the world experiences a shift towards an increasingly urbanized population, however, exposure to these health benefits are less likely to occur without specific interventions that aim to enhance the necessary dose. Surprisingly, there are relatively few studies that specifically explore dose-response or even a minimum dose required to derive these health benefits. Those that do exist report conflicting evidence on both nature's ability to buffer against stress and the ability of contextually different nature scenes in promoting more effective health outcomes. The current study subsequently aimed to systematically disentangle certain aspects of nature to identify what, if any, is the most effective and efficient way in realizing some of these health benefits. This study experimentally investigated whether a single, acute exposure (i.e. 5 minutes) to contextually different nature images (i.e. beach and forest) buffered, or protected, an individual from a psychosocial stress task. A total of 58 participants aged between 18-63 from the University of Auckland were recruited. Participants were randomly assigned to either a beach, forest, or control group for an hour and a half laboratory session where they completed a series of health related questionnaires while simultaneously having their heart rate data recorded as they engaged in a reading, visual (i.e. beach, forest, or neutral images) and psychosocial stress task. Despite significant task effects noted throughout the experimental protocol, the results of the current study demonstrated that there was no significant difference in physiological health measures (i.e. heart rate and heart rate variability) or mood measures between the groups following the psychosocial stress task, nor was there a significant difference in psychophysiological health measures between those exposed to beach as opposed to forest images. In sum, this study demonstrated that a single acute dose, in this case, a 5-minute exposure to images of nature, does not buffer against stress, nor does contextually different nature images produce better health outcomes. While findings of this study do not support the main hypotheses, an interesting pattern emerged within the psychological data that contributes to a gap within the literature. This study was able to demonstrate that exposure to images of nature, both beach and forest scenes, influenced very specific affective states (i.e. positively valence, low arousal). This finding highlights the distinctive influence that nature has on mood, as opposed to other studies that report a generalized improvement in mood. Furthermore, future studies may build on the current study by considering other aspects of 'nature dose', including duration, intensity, and frequency of exposure to further understand how to better utilize nature as a health intervention against stress.