Attention Restoration Theory II: a systematic review to clarify attention processes affected by exposure to natural environments

ABSTRACT

Attention Restoration Theory (ART) predicts exposure to natural environments may lead to improved cognitive performance through restoration of a limited cognitive resource, directed attention. A recent review by Ohly and colleagues (2016) uncovered substantial ambiguity surrounding details of directed attention and how cognitive restoration was tested. Therefore, an updated systematic review was conducted to identify relevant cognitive domains from which to describe elements of directed attention sensitive to the restoration effect. Forty-two articles that tested natural environments or stimuli against a suitable control, and included an objective measure of cognitive performance, had been published since July 2013. Articles were subjected to screening procedures and quality appraisal. Random effects meta-analyses were performed to calculate pooled effect sizes across 8 cognitive domains using data from 49 individual outcome measures. Results showed that working memory, cognitive flexibility, and to a less-reliable degree, attentional control, are improved after exposure to natural environments, with low to moderate effect sizes. Moderator analyses revealed that actual exposures to real environments may enhance the restoration effect within these three domains, relative to virtual exposures; however, this may also be due to differences in the typical lengths of exposure. The effect of a participants’ restoration potential, based upon diagnosis or fatigue-induction, was less clear. A new framework is presented to qualify the involvement of directed attention-related processes, using examples of tasks from the three cognitive domains found to be sensitive to the restoration effect. The review clarifies the description of cognitive processes sensitive to natural environments, using current evidence, while exploring aspects of protocol that appear influential to the strength of the restoration effect.

KEYWORDS:

• Executive functions
• greenspace
• mental fatigue
• restorative environments

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Acknowledgments

We would like to thank Heather Ohly and her co-authors for their contact and support during the completion of this article. We would also like to thank Terry Hartig for his valuable input on addressing aspects of research designs and analysis of data. Finally, we would like to thank all authors for their cooperation and patience during the review, quality assessment, and data synthesis. MPS’s research is funded by a grant from Trygfonden, Denmark (ID#109942). The opinions expressed are the authors only and are not necessarily those of Trygfonden, Denmark. No potential conflicts of interest were reported by the authors.

Additional information

Funding

This work was supported by Trygfonden, Denmark [ID#109942].