In her new book Good Nature, Oxford professor of biodiversity Kathy Willis explains how exposure to natural scenery can benefit our health, mood and functioning.
Understanding the causes of elevated stress in our bodies, and, on the flip side, what makes us less stressed, is an emerging branch of medicine. This is because high stress makes us more susceptible to a whole plethora of sicknesses. These include heart attacks, strokes, cancers, diseases associated with impaired inflammatory/immune responses, fatigue and depression.
Stress is manifest in our bodies through three main and often interconnected pathways. First, when we are stressed, changes occur in our nervous system (brain, spinal cord and peripheral nerves), triggering involuntary changes to our breathing rate, heart-rate variability and width (narrowing) of blood vessels. Second, stress can trigger our endocrine system to release hormones such as cortisol and adrenaline from our glands to mobilise energy sources and increase our heart rate and blood pressure. Third, when we are stressed, this can affect our psychological state. Anxiety, depression and low moods are the most common symptoms.
Given all of these adverse effects, understanding how to reduce and manage stress is an important branch of medicine. Common medications to manage symptoms of stress include tranquillisers, beta-blockers, antidepressants and selective serotonin reuptake inhibitors (SSRIs), among others. But increasingly, healthcare practitioners are starting to explore other approaches and treatments, to prevent stress occurring in the first place and reduce elevated levels. And this is where taking time to view natural scenes on the horizon is revealing some fascinating findings.
The first is that when we look at a natural landscape scene compared to an urban one, even on a computer, we become calmer. For example, a team of scientists from the Centre for Environment, Health and Field Sciences in Japan’s Chiba University asked female students to look at photos of a forest and of high-rise office blocks for just 90 seconds each. Clear results emerged: when viewing the natural scene photo, physiological calming was evidenced in their brain activity, and psychological relaxation was recorded in students’ responses to the questionnaires. These indicated increased perceptions of feeling “comfortable”, “relaxed” and “natural”.
It would appear that viewing natural scenes can trigger pathways in our bodies that make us calmer and less anxious. However, this study, and a number of others showing similar findings, involved healthy individuals who were sitting in a quiet room looking at images on a computer screen – hardly the sort of environment that most often results in us being stressed.
So, do we get the same reactions in more “real-life” stressed situations such as in a highly pressurised workplace? This is where a second interesting finding is emerging. A large number of studies are now showing that when we are stressed, we recover much quicker if we look at natural rather than urban scenes.
A nice example of this is the findings of an experiment where office staff were asked to sit at a desk for 10 minutes and view either a set of slides showing nature scenes typical of those you might see from an office window (trees, open grasslands), or of built environments (office blocks, streets with cars, and so on). They then underwent a five-minute activity to elevate levels of mental and physical stress. This involved studying a series of numbers on a screen and having 10 seconds to write them down in the correct order. The participants were told that a buzzer would sound each time an incorrect answer was given.
Viewing natural scenes can trigger pathways in our bodies that make us calmer and less anxious.
In fact, and somewhat unfairly I think, the buzzer was sounded twice during the test irrespective of whether they got the answer right or not. This would definitely stress me out. The participants had continuous measurements taken of their breathing (frequency and depth), blood pressure and heart-rate variability to measure their physiological indicators of stress. They also filled in two psychological questionnaires, one before and one after the stress test.
The results were intriguing. As expected, all participants showed elevated levels of stress during the test. But those who had viewed scenes of nature beforehand showed significantly faster recovery rates from the stressful incident compared to those who viewed the urban scenes. They also showed less psychological stress.
The take-home message from this, of course, is that we should all look at natural scenes either out of the window or as photos on our computer screen if we are about to encounter a stressful situation at work. But how does it work? Why do we get faster recovery rates when looking at natural scenes? To explain this, a leading environmental psychologist called Roger Ulrich and colleagues proposed the so-called Stress Reduction Theory (SRT) in the early 1990s. They argued that we have two biologically predetermined responses to viewing nature. First, we have a preference for, and instinctively pay attention to, natural scenes. Second, when we do so, it leads to a more “positively toned emotional state”. Together, these will trigger automatic physiological responses in our bodies when we view natural scenes, which cause us to recover faster from stress.
Better cognition
In contrast, they argued that the same does not happen when we view urban environments – instead, these can hamper recuperation, especially after stressful events. Since it was first proposed, many studies have tested this theory and shown it to be broadly correct – when we view natural environments, even from indoors, physiological indicators of stress in our bodies show faster rates of recovery. Fascinating stuff – never before has looking out of the window on to the garden seemed such an attractive pastime. However, another equally important thing that appears to happen when we look at natural scenes is that it improves our mental ability associated with certain tasks – or so-called cognitive functioning.
Cognitive functioning refers to the processes of learning, thinking, reasoning, remembering, problem-solving, decision-making and attention. While some of our cognitive functions decline as we get older, many change very little across our life span: and some, such as vocabulary, may even improve in later life. Cognitive functioning and performance also vary greatly between individuals, whether they are children, adolescents or adults.
Of most relevance here, however, is the fact that some aspects can be improved at whatever age – and this is where studies showing how our cognitive function changes when we see natural views on the horizon are important. Fascinatingly, it would appear from a large body of emerging research that if we view natural compared to urban scenes when taking breaks, we see significant improvements in our working memory, attention control and cognitive flexibility (our ability to switch between thinking about two different concepts or to think about multiple concepts simultaneously). Importantly, this is apparent in all age groups – it is never too late to start staring out of the window! – but some of the most interesting studies are those involving school-aged children. I will mention just one here to give a flavour of the data that is emerging.
This study was carried out in 2015 by a team of scientists led by Payam Dadvand, a research professor at the Barcelona Institute for Global Health in Spain. Dadvand examined whether there was a difference in the cognitive development of primary school children who saw natural scenes on a daily basis. The quantity of natural green space that the children encountered in their everyday lives was measured using satellite imagery.
Three areas were mapped: a 250m buffer around each child’s home, a 50m buffer around the children’s school buildings, and the amount of natural green space the child would encounter in their commuting route to school. The experiment was carried out over an entire school year in 2012-13 and involved 2593 primary school children whose average age was 8.5 from 36 schools.
While the neighbourhoods of the schools were all similar in socio-economic factors, additional data on maternal education, parental employment, marital status and ethnicity was collected to understand if these variables would influence the outcome. The cognitive development of the children was measured over a year. Tests were undertaken every three months to assess working memory and attention.
Remarkably, their findings showed that, regardless of socio-economic factors or family background, the greater the amount of natural green space that the children encountered in their everyday lives, the better their monthly progress in working memory and attentiveness.
Possibly even more important was the finding that the strongest measure for improved cognitive performance was the amount of green space surrounding the children’s school buildings, not on their commuting route. The authors suggested this was most likely to be reflecting the fact that, since children spend most of their day at school inside, seeing natural scenes through the windows will therefore have most influence on improving their cognitive performance. This has important policy implications for the design and location of schools.
Restorative functions
But why do we see these clear improvements in cognitive function when we look at natural scenes? What is the process responsible? Explanations have been suggested in a theory from the field of the psychology of natural scenes, called Attention Restoration Theory. This was proposed by two professors of psychology at the University of Michigan, Stephen and Rachel Kaplan, in a set of seminal papers published in 1989 and 1995. They hypothesised that views of nature improve our cognitive functioning because of the restorative effect that they have on our directed attention.
In our everyday lives, our brains rely heavily on cognitive resources that direct attention towards a task that requires focus, while simultaneously ignoring background distractions, such as people chatting and computers beeping to remind us that we have new emails.
In psychology, this cognitive resource is known as directed attention. However, our capacity to direct attention in this way cannot be sustained indefinitely, which is why our ability to concentrate tends to wax and wane during the day. Prolonged directed attention also leads to a state of mental fatigue, which is something we need to avoid as it is associated with, for example, poorer decision making, more errors and lower levels of self-control.
The Attention Restoration Theory proposes that seeing scenes of nature restores our directed attention, because viewing natural scenes draws instead upon our involuntary attention. This is when our mind is diverted (distracted) towards some other activity, for example something glimpsed in our peripheral field of vision, rather than being consciously and deliberately selected or focused on by us.
It is never too late to start staring out of the window.
But why do natural scenes draw on our involuntary attention more? The Kaplans propose that this is because, counter-intuitively, they contain far fewer stimuli that require our notice. So, when we are looking at natural scenes, our directed attention is given a “mini-break”, allowing it to recover and replenish. When we then return to tasks that require focus, we show better cognitive performance because our directed attention has recovered.
To summarise: there appears to be a strong body of evidence showing that looking at natural scenes triggers psychological and physiological responses that bring about calming, faster recovery from stress and improvement in our working memory and attention.
An edited extract from Good Nature: The New Science of How Nature Improves Our Health, by Kathy Willis (Bloomsbury), on sale now.
Nature’s Balm
■ Thanks apparently to compounds they exude, walking through pine forests makes us measurably calmer and more relaxed.
■ Listening to the sounds of nature improves physiological and psychological measures, including post-operative pain, according to a synthesis of studies.
■ A number of studies suggest humans prefer wide canopy types of trees, like oaks and acacias, rather than pointy-shaped trees like conifers.
■ People of all ages tend to prefer savanna landscapes, even if some have never seen them in real life.
■ Viewing green and blue colours seems to trigger neural activity in areas of our brains associated with enhanced attentional and cognitive processes.
■ Combinations of green-yellow and bright green in plants appear to have the most positive neural results for calm and focus.
■ Viewing real flowers seems to decrease physiological stress and improve mood more than fake ones.
