Nature and the Brain

Living in the age of high technology, our devices provide easy access to unending amounts of information. Compared to 1980, we cram in an extra 4.4 hours per day of information consumption outside of work, an increase driven by screen-based media. Is it time for a mental detox?

We need a break

In a somewhat ironic way, science and technology is providing a greater understanding of nature’s role in mental detoxification. Research makes it clear that we need an occasional break from techno-overload. Powering down and avoiding distractions allows for mindful engagement with nature.

Wired for info-desire

Since good information can promote our safety and well-being, it should not be surprising that the human brain is wired for info-desire. Seeking information can feel good; it is a process rewarded through brain pathways in the same way we are rewarded for seeking sustenance and shelter.

Overtaxed brains

But the brain can easily be overtaxed in its distracted efforts to separate information of dubious value from that which might serve us well. And just as the brain’s reward system can be hijacked by kilojoule-dense junk food, the lure of instant screen-based information can be overpowering, displacing health-promoting activities such as exercise, meaningful social interaction and the rejuvenating act of contemplation.

Screen time and depression

Until recently it was assumed that stressed individuals are simply drawn to more screen time because of their existing mental state. However, recent studies show that when otherwise healthy individuals are followed for a number of years, the accumulation of screen time can be a risk factor for, and not a mere consequence of, symptoms of depression and anxiety.

Info-overload

Cyber-based information overload is linked to more frequent and severe health problems, and the overload makes it difficult to recognise that an escape to contemplation can be an effective solution. The lure of screen-based devices and entertainment, so-called videophilia, has increased in tandem with a marked decline in outdoor, nature-based recreation.

Crowding out nature

Since there are a fixed amount of hours in a day, videophilia can displace time otherwise available for mindful engagement with nature—vegetation, water, animals, sights, natural light, sounds and aromas.

The good news? Even brief engagement with nature is proving to be a simple and inexpensive means to improve mental outlook and clear the brain fog associated with info-overload.

Nature promotes health

Several studies build the case for nature as a stress buffer and promoter of health, and in particular, mental health. Researchers from the United Kingdom, Japan, China and the US have connected parks, gardens, green areas and forests with lower mortality from cancers, circulatory diseases, stroke and other causes.

Greater life satisfaction

Unsurprisingly, neighbourhood greenness within urban geography is associated with individual life satisfaction. A closer examination of 4500 urban adults revealed that those living in closest proximity to areas containing a high amount of green space were less likely to experience negative health impacts of stress.

Fewer health complaints

Among those in the same study who had experienced recent life stressors (major losses, financial problems, relationship problems, legal issues), having a more dense green space within a 3 km radius was associated with fewer health complaints compared to those with a low amount of green space.

Reduction in biomarkers for disease

The practice of Japanese Shinrin-yoku (“forest bathing”), or spending time walking or contemplating in a forest (compared to an urban setting), is associated with lower stress hormone levels and other physiological markers of stress. Visits to forests have also been shown to improve the activity of natural killer cells, our frontline immune defenders.

Lower stress

A separate study involving more than 11,000 adults showed that individuals living more than 1 km away from green space were 42 per cent more likely to report high stress and had the worst scores on evaluations of general health, vitality, mental health and bodily pain.

Subjective reports of improved mood have been corroborated with objective markers of stress physiology. These studies show a consistent pattern of rapid and more complete recovery from experimental stress scenarios after viewing vegetation-rich nature scenes.

Brainwave activity measured with an electroencephalogram (EEG) confirms higher alpha wave activity when viewing scenes of vegetation-rich nature compared to urban built scenes, indicating a state of relaxed wakefulness and lowered anxiety.

Reduced illness

After examining the medical records of 195 family physicians, Dutch researchers reported that the annual prevalence rate of 15 of the top 24 disease clusters was lowest among those with the most green space within a 1 km radius from home.

Better mental health

A mere 10 per cent increase in green space over the group average was associated with resiliency against chronic disease. Importantly, those with 10 per cent or less green space within 1 km had a 25 per cent greater risk of depression and a 30 per cent greater risk of anxiety disorders compared to those with the highest amount of green space near the home.

More caring attitudes

In a series of Korean brain imaging studies, viewing nature scenes increased activity in areas of the brain associated with heightened empathy and altruistic motivation. In contrast, viewing urban scenes increased activity in the amygdala, an area associated with threat and anxiety.

Better memory

Finally, we can examine the value of engagement with nature in the age of distraction. In a number of studies, scientists induce mental fatigue in healthy subjects via cognitively demanding tasks, and then half of the group view nature scenes, while the others view urban built scenes.

Upon repeat cognitive testing, those who view nature scenes have enhanced accuracy in target detection, faster reaction time and a higher number of correct responses to challenge and better memory recall.

Improved mental performance

In research involving mentally fatigued adults, a walk (for a little less than an hour) in a vegetation-rich urban park (versus city streets) significantly improves mental performance.

Similar findings have been reported in children with attention deficit hyperactivity disorder (ADHD). And research shows that classroom, dormitory and cafeteria views to green vegetation are underappreciated factors in academic performance on standardised tests.

Get into green

We may be serious about being green, but it’s time to remind ourselves about getting into green—as little as 20 minutes can restore our tired brains and promote happiness.