This study assessed the evidence that exists for the attention restoration values of exposure to natural environments and images.
In order to investigate the existing literature, this project undertook a systematic review of experimental studies that have compared natural settings with other (non-natural or urban) settings.
It used a systematic approach to identifying, appraising and synthesising relevant, existing and quantitative research evidence. Studies that only assessed the perceived benefits of natural settings were not be included.
The research team worked closely with Alison Bethel at PenCLAHRC, and asked if the attention restoration values of nature are different for:
Different groups of people (e.g. adults, children)
Varied prior demands (e.g. people with stressful jobs)
Different types of natural settings (e.g. seascapes vs. landscapes)
Different types of exposure or engagement
People with different opinions about natural settings
They focused on understanding the extent to which differences between various environments could be explained by confounding factors such as physical activity, whether the impacts persist over the long term, and assessing what evidence exists for causal mechanisms.
Attention Restoration Theory (ART) (Kaplan, 1989, 1995) suggests that mental fatigue and concentration can be improved by time spent in, or looking at nature. The capacity of the brain to focus on a specific stimulus or task is limited and results in ‘directed attention fatigue’. ART proposes that exposure to natural environments encourages more effortless brain function, thereby allowing it to recover and replenish its directed attention capacity.
According to Kaplan, the natural environment must have four properties in order to provide this restorative effect:
Extent (the scope to feel immersed in the environment)
Being away (providing an escape from habitual activities)
Soft fascination (aspects of the environment that capture attention effortlessly)
Compatibility (individuals must want to be exposed to, and appreciate, the environment)
It is thought that soft fascination plays the key role, with the other three properties enhancing or sustaining fascination.
Although ART is a widely cited concept in the literature, it is unclear how much empirical evidence there is to support this theory.
Research Recommendations
This systematic review highlighted a number of issues for the future research agenda:
(1) It is unclear how validity and reliability of measures of directed attention should be assessed, and which are likely to be most sensitive to nature exposure. More needs to be done to articulate which specific characteristics of a task might be important and thus gain a better understanding of exactly which underlying attentional processes nature may influence the most.
(2) Meta-analysis would be facilitated if the ART community could articulate more clearly which measures of attention are likely to measure the impact of restoration most appropriately, and then use these measures in a consistent way across multiple studies.
(3) Researchers and journal editors should encourage complete reporting of experimental outcomes, including publishing negative findings, so that accurate assessments can be made of the attention restoration potential of natural settings.
(4) Investigators and journal editors should work together to agree the key elements of research reporting and experimental conduct to allow an accurate and fair appraisal of study quality to be made by readers and reviewers.
(5) Future studies could usefully assess the impact of employing multiple measures, and the order in which they are administered, on the outcomes of attention themselves.