By Craig Weatherby
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.
Back in 2011, we reported on studies suggesting that natural settings like parks and woodlands refresh the brain, and may even improve physical health.
Affirming an idea called “attention restoration theory
”, natural environments – even simulated ones provided by murals – improved participants' moods, levels of relaxation, and capacity for “directed attention
” … the ability to focus on tasks and maintain calm.
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.
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 … and 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:
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 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!
Aspinall P, Mavros P, Coyne R, Roe J. The urban brain: analysing outdoor physical activity with mobile EEG. Br J Sports Med. 2013 Mar 6. [Epub ahead of print]
De Young R. Restoring the capacity to direct attention. Accessed at http://www-personal.umich.edu/~rdeyoung/publications/art.html
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Korpela KM, Ylén M, Tyrväinen L, Silvennoinen H. Favorite green, waterside and urban environments, restorative experiences and perceived health in Finland. Health Promot Int. 2010 Jun;25(2):200-9. doi: 10.1093/heapro/daq007. Epub 2010 Feb 22.
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Wikipedia. Attention restoration theory. Accessed at http://en.wikipedia.org/wiki/Attention_Restoration_Theory