Vitamin G: How a Daily Dose of Green Improves Brain Function

Can wilderness and waterside walks lift mood, relieve stress…and allow the aimless reflection that helps balance and focus our minds and spirits?

As John Muir wrote, “Everybody needs beauty as well as bread, places to play in and pray in, where nature may heal and give strength to body and soul.”

But, to quote a certain 1980’s hair band from Boston, is this “more than a feeling”?

It turns out that in fact, conventional wisdom about the restorative power of nature enjoys an increasing amount of scientific evidence.

The human brain’s ability to stay calm and focused can be swamped by the insistent attention demands and sensory distractions of urban and office living.

Over the course of hours, days, and weeks, this sensory/attention overload leads to the “brain fatigue” that makes people in cities and offices distracted, irritable, and less effective.

Nature proves restorative…the wilder the better

Many studies have now been conducted, all designed to test something called Attention Restoration Theory (ART).

The goal has been to quantify the restorative powers of nature and discover how natural settings enhance people’s thinking and mood. These studies suggest that natural settings like parks and woodlands refresh the brain, and may even improve physical health. So we’re calling this nutrient “Vitamin G,” and we need to make sure we get our daily allowance of getting outside and enjoying some Green.

Natural environments – even simulated ones provided by murals – improved study participants’ moods, levels of relaxation, and capacity for “directed attention”…the ability to focus on tasks and maintain calm.

Several years ago, University of Michigan scientists reported on two “experiments that show that walking in nature or viewing pictures of nature can improve directed-attention abilities…thus validating attention restoration theory.” (Berman MG et al. 2008)

And addressing the reasons for nature’s brain benefits, they noted that “Nature, which is filled with intriguing stimuli, modestly grabs attention in a bottom-up fashion, allowing top-down directed-attention abilities a chance to replenish.”

In contrast, they wrote, “…urban environments are filled with stimulation that captures attention dramatically and additionally requires directed attention (e.g., to avoid being hit by a car), making them less restorative.” (Berman MG et al. 2008)

And indoor environments are ruled by straight lines and flat, smooth surfaces, with none of the random or “fractal” shapes and movements seen everywhere in nature.

Objective scientific tests show that natural environments accelerate recovery from surgery and restore people’s ability to engage in directed attention…which cannot be sustained indefinitely.

Compared with people who live amid concrete, those who dwell near nature enjoy lower levels of the stress hormone cortisol, while children with attention problems performed better on cognitive tests after walking through natural settings.

Scandinavian and student research affirms nature’s relaxing power

Finnish researchers reported in 2010 that most of 1,273 study participants believed that time spent in their favorite outdoor areas and woodlands were more relaxing and restorative than time spent in their favorite built-up urban settings or city parks (Korpela KM et al. 2010).

Encouragingly, those who had the most stress reported the greatest relief from time in relatively untamed nature.

However, those who needed nature the most were the least likely to seek it out:

“The more worries about money and work a person had, the more stressed a person had felt during the last year, the less energetic she/he had felt, the lower was the number of visits to the favorite place (during the last 6 months) and the lower the typical level of restorative experiences.”

The lesson, it seems, is that if you are feeling stressed, depressed, or frazzled, it’s harder but even more important to get yourself into the woods.

Portable brain scans affirm nature’s brain benefits

Harder evidence came from clinical studies employing the electroencephalogram (EEG)…a device that reads brain waves.

Volunteers in labs were shown photographs of either natural or urban scenes with electrodes attached to their heads. Their brain waves displayed more characteristics of calm in response to the nature scenes.

But until the recent advent of a portable electroencephalogram, it wasn’t possible to study peoples’ brains while they were walking through urban areas and green parks.

Now, a novel study from Scotland provides hard evidence that nature actually affects brain function in beneficial ways.

Scottish study read brain waves on the move

Researchers from Edinburgh’s Heriot-Watt University and the University of Edinburgh attached a portable EEG called the Emotiv EPOC to the scalps of 12 healthy young adults, under an ordinary cap (Aspinall P et al. 2013).

The electrodes sent brain readings wirelessly to laptops carried in the participants’ backpacks.

All 12 volunteers took a walk of about a mile and half through three distinctly different areas of Edinburgh, lasting about 25 minutes:

Zone 1 – Shopping district with historic brick buildings, moderate pedestrian traffic, and light vehicle traffic.
Zone 2 – Park-like green space.
Zone 3 – Busy commercial district with heavy auto traffic and concrete buildings.

The Emotiv EPOC provided continuous recordings from brain-wave channels associated with five different states:

Excitement
Frustration
Engagement (directed attention)
Long-term (LT) Excitement
Meditation

Afterwards, the scientists analyzed the volunteer’s brain wave records using a sophisticated new mathematical method.

The analysis showed evidence of lower engagement and arousal, and higher meditation when moving into the “green zone,” and higher engagement when moving out of it.

The walkers were still paying attention in the green zone, but it was the kind that brain researchers call “effortless” or “involuntary” attention.

In other words, effortless/involuntary attention allows us to reflect and it refreshes brains fatigued by the continuous attention demanded by offices and city streets.

As the Scottish team said, “Systematic differences in EEG recordings were found between three urban areas in line with restoration theory. This has implications for promoting urban green space as a mood-enhancing environment for walking or for other forms of physical or intellectual activity.”

The takeaway seems obvious…we should all take every opportunity to get outside and let our minds wander and wonder! A walk in the park…better yet, in the woods or along the water, can help people who feel blue or frazzled. Take a daily walk, ride, or paddle in the wildest places nearby and surround yourself with scenes of nature.

Sources

photo credit: goingslo cc