Comparing the effect of mindful and other engagement interventions in nature on attention restoration, nature connection, and mood

Highlights

• We tested three cognitive engagement interventions in nature.

• Mindfulness in nature was contrasted with mind wandering and directed engagement.

• All groups reported similar levels of nature connection and positive affect.

• Mind wandering group reported lowest negative affect after nature experience.

• The control group performed best on an attention task after nature experience.

Abstract

Mindful engagement interventions have been shown to improve psychological benefits of nature experiences but to date there has been little evaluation of their efficacy compared with other forms of engagement. An online experimental study was conducted to compare different forms of engagement with nature. Before and after a 20-min outdoor experience, participants (n = 215) completed surveys on state-mindfulness, connection with nature, and mood, and then the Sustained Attention to Response Task (SART). Participants were randomly allocated to one of four engagement intervention groups: mindful engagement, directed engagement, mind wandering, and an unguided control group. The groups did not differ on connection with nature or positive affect after the nature experience, when accounting for the baseline measures, however the mind wandering group reported significantly lower negative affect than the directed engagement group. Overall, SART outcomes indicated that the unguided control group had the greatest level of attention restoration, suggesting that all three engagement interventions taxed the attention system. Mediation analyses indicated that there was an indirect effect of state mindfulness on the psychological outcomes, primarily for the mindful engagement group when contrasted with the unguided control. The findings challenge the idea that all forms of heightened engagement enhance the experience of nature and resulting psychological outcomes. We use these findings to outline considerations for designing and applying engagement interventions in nature for specific outcomes.

Introduction

Research over the past decade has explored the effect of various nature-based engagement interventions on psychological benefits of spending time in nature (Duvall, 2011; Korpela et al., 2017; Lumber et al., 2017). Several of these interventions apply qualities of mindfulness to the nature experience, such as nonreactivity and curiosity (e.g., Lymeus et al., 2018; Nisbet et al., 2019), setting them apart from other engagement interventions including those using imagination and abstract thought (e.g., Duvall, 2011). Concurrently, researchers have hypothesised and observed varying psychological outcomes associated with engagement interventions, including mood (Korpela et al., 2017) and connection with nature (Lumber et al., 2017). Despite this diversity, only one study to date has compared outcomes of different engagement interventions on a single set of psychological outcomes (Pasanen et al., 2018). Further, theoretical accounts are emerging of mind wandering as an alternative form of engagement in nature (Williams et al., 2018), warranting its consideration alongside existing engagement concepts. To progress understanding of engagement interactions in nature, it is essential to compare and contrast mindful and other engagement interventions, so that they can be designed to support desired outcomes.

Heightened engagement in nature may influence commonly reported psychological outcomes of nature experiences. They include attention restoration (Ohly et al., 2016; Stevenson et al., 2018), mood (McMahan & Estes, 2015), and connection with nature (Lumber et al., 2017; Mayer & Frantz, 2004). Improved attention performance has been observed after two-weeks of engagement-enhancing tasks conducted in nature (Duvall, 2011), after a walking intervention with restoration-based engagement exercises (Pasanen et al., 2018), and when participants were simply instructed to ‘pay attention closely’ to vegetation in photographs (Y.-H. Lin et al., 2014). While satisfaction with engagement tasks has been associated with mood enhancement (Korpela et al., 2017), experimental studies have not found effects of engagement exercises on self-reported mood (Lumber et al., 2017; Pasanen et al., 2018). Heightened engagement with nature may also improve one's feeling of connection with nature, through a sense of immersion in nature (Weinstein et al., 2009), or specifically designed engagement exercises (Lumber et al., 2017). Within these studies, there is a relatively consistent finding that engagement in nature improves attention performance, with little evidence for engagement impacting mood. The mixed findings may be the result of diverse designs of engagement interventions, though associations between specific engagement forms and outcomes remain unclear. The current study aimed to experimentally examine the effect of various forms of engagement on psychological outcomes of nature. In the following section, we review development of engagement exercises in the literature, and specify theoretical contrasts between forms of engaging in nature.

Kaplan (2001) proposed that a heightened engagement or mental resonance with the environmental experience would support restorative outcomes, and since then several studies have designed engagement tasks to strengthen outcomes of nature experiences. Duvall (2011) developed exercises to heighten interest of the environment during a two-week walking intervention. Some exercises were quite abstract (e.g., “How would this area be different if everyone had to grow their own food?“), while others were more directed (e.g., “Focus on sounds”, Duvall, 2011, p. 29). The theoretical foundation for the exercises did not clearly relate to psychological restoration in Duvall's study, but other researchers have built on these ideas and designed exercises that test theoretical pathways to restorative outcomes (Korpela et al., 2017; Pasanen et al., 2018) and nature connection (Lumber et al., 2017). For example, Pasanen et al. (2018) developed restoration-enhancement exercises that conceptually align with theoretical pathways described in attention restoration theory (ART; Kaplan, 1995), and compared their efficacy with Duvall's awareness-enhancing exercises (2011). Participants in the restoration-enhancement condition had better sustained attention after the nature experience, while both the restoration- and awareness-enhancing groups reported comparable improvements in positive mood (Pasanen et al., 2018). These studies demonstrate that the form of engagement is clearly important in the effect on outcomes and thus needs to be carefully considered when designing such exercises. The current study follows this line of reasoning: we developed and contrasted theoretically driven engagement exercises, and extend past research by using mindfulness as a starting point to identify and distinguish key qualities of nature-based engagement exercises.

Mindfulness has received growing interest as a form of engagement intervention in nature experiences, and its characteristics can provide a basis to compare qualities and forms of engaging in nature (Macaulay et al., 2022). Mindfulness involves awareness of the present moment, which includes the external (sensory experience) and internal experience (thoughts and emotions), with qualities of curiosity, acceptance, and without judgment or reactivity (Bishop et al., 2006; Cardaciotto et al., 2008; Kabat-Zinn, 2003). Mindfulness thus differs from other engagement exercises that direct attention to nature: where other forms of engagement may be external (e.g., focusing on sounds and smells; Weinstein et al., 2009) or internal (e.g., observing one's mood; Korpela et al., 2017), mindful engagement can be characterised as an awareness of the whole experience – external and internal – that includes acceptance and nonjudgment (Bishop et al., 2006; Cardaciotto et al., 2008).

Mindfulness has been applied in heterogenous ways in studies of nature experience. Studies have compared the effects of established mindfulness interventions in natural settings with indoor or built environments, finding benefits of mindfulness in nature on attention performance (Lymeus et al., 2018), connection with nature, and stress reduction (Choe et al., 2020). Short walking interventions in nature with mindful engagement have demonstrated benefits for connection with nature and negative affect (Nisbet et al., 2019), and anxiety and happiness (Shin et al., 2013). Studies have found that being in nature can facilitate state mindfulness or present-centred awareness (Brymer et al., 2021), and that state mindfulness can mediate the effect of nature exposure on affect (Stewart & Haaga, 2018). Brymer et al. (2021) call for further research on the mediating effects of mindfulness in nature, to better understand its role in psychological outcomes of nature experiences. This would help delineate the key differences between mindful engagement interventions in nature and other forms of engagement in nature.

Mind wandering is a form of engagement that has received some attention for its role in supporting restoration in nature experiences (Williams et al., 2018), yet has not been applied as an engagement technique in empirical studies. Mind wandering involves an internally oriented awareness (Schooler et al., 2014), with relatively little cognitive effort or control (Christoff et al., 2016). While mind wandering is commonly linked with negative outcomes such as lower mood (Killingsworth & Gilbert, 2010), it may lead to improvements in mood when the content of thoughts is interesting or stimulating (Franklin et al., 2013; Schooler et al., 2014). Mind wandering in nature has also been proposed to support attention restoration via a process of gentle shifting between internal mind wandering and external fascination with nature (Williams et al., 2018). There is some evidence for these ideas, where settings that are highly rated for restorativeness are also rated highly for the potential for introspection and mind wandering (Cervinka et al., 2020). Mind wandering offers an interesting research direction in the context of engagement in nature experiences. However, with mixed findings on the potential for mind wandering to improve or lower mood (Franklin et al., 2013; Killingsworth & Gilbert, 2010), we would expect exercises that are designed to draw awareness to nature (e.g., through mindfulness or other awareness-enhancing activities) would be more restorative than internally-oriented mind wandering.

This study aimed to compare the effectiveness of three different engagement interventions in nature, on psychological outcomes. During a brief nature experience, a mindful engagement, a directed engagement, and a mind wandering intervention were compared with an unguided control condition. The interventions were designed to be theoretically distinct from one another. The mindful engagement intervention was designed with reference to prior studies that implement short, guided mindfulness interventions focusing on the breath and physical sensations (Arch & Craske, 2006; Aspy & Proeve, 2017) and to internal sensations (Kiken & Shook, 2011), and studies that apply mindfulness in nature (Lymeus et al., 2018; Nisbet et al., 2019). The directed engagement intervention was designed by drawing on exercises shown to be effective in encouraging attention to the nature experience (e.g., Duvall, 2011), but with qualities that contrast with mindfulness (for example, encouraging elaborative and judgmental thought). Additionally we drew on designs of active control groups in mindfulness literature, that use physical relaxation exercises (Aspy & Proeve, 2017; Rahl et al., 2017), movement and imagery (MacCoon et al., 2012). The mind wandering intervention was based on studies that use mind wandering as a control condition for mindfulness interventions, where participants are instructed to let attention move away from the present moment (Arch & Craske, 2006; Kiken & Shook, 2011).

To examine whether mindfulness itself is an important factor in such interventions, we additionally aimed to test whether the level of state mindfulness during the experience played a key role. We aimed to contribute to existing literature that explored the role of state mindfulness during nature exposure (e.g., Brymer et al., 2021; Stewart & Haaga, 2018) by testing whether state mindfulness mediated the effects of the engagement interventions on psychological outcomes of the nature experience.

Hypothesis 1

A mindful engagement intervention would improve outcomes of, a) state mindfulness, b) connection with nature, c) positive affect, d) negative affect, and e) sustained attention, to a greater degree than other intervention groups.

Hypothesis 2

The directed engagement intervention would improve all outcomes greater than the mind-wandering intervention and the unguided control group.

Hypothesis 3

Engagement interventions in nature would be indirectly associated with psychological outcomes through a higher level of state mindfulness during the experience.