How a walk in nature restores attention

New research from psychology researchers at the University of Utah helps prove what American authors John Muir and Henry David Thoreau tried to teach more than 150 years ago: time spent in nature is good for the heart and soul.

Amy McDonnell and David Strayer show that it’s also good for the brain. Their latest research, conducted at the university’s Red Butte Garden, uses electroencephalography (EEG), which records the brain’s electrical activity using small discs attached to the scalp, to measure participants’ attentional capacity.

“A walk in nature improves certain executive control processes in the brain beyond the benefits associated with exercise,” concludes the study published in Scientific reports. The article contributes to the growing body of scientific literature on how natural environments contribute to a person’s physical and mental health. The university itself recently created a new research group, Nature and Human Health Utah, which is exploring these questions and proposing solutions to bridge the gap between humans and nature.

Many researchers suspect that a primal need for nature is written into human DNA and that diminishing access to nature puts our health at risk.

“There is an idea called biophilia that basically says that our evolution over hundreds of thousands of years has led us to have more connections or love for natural living things,” said Strayer, the psychology professor. “And our modern urban environment has become this dense urban jungle with cell phones and cars and computers and traffic, just the opposite of that kind of restorative environment.”

Strayer’s previous research on multitasking and distracted driving associated with cell phone use has attracted national attention. Over the past decade, his lab has focused on how nature affects cognition. The new research was part of McDonnell’s dissertation as a graduate student in Strayer’s Applied Cognition Lab. She has since completed her doctorate. and continues his research on attention as a postdoctoral fellow at the University of Utah.

The study, conducted in 2022 between April and October, analyzed EEG data recorded on each of the 92 participants immediately before and after undertaking a 40-minute walk. Half passed through Red Butte, the arboretum at the base of the university, and the other half passed through the nearby asphalt-laden medical campus.

“We start by asking participants to perform a very draining cognitive task in which they count backwards from 1,000 by sevens, which is really difficult,” McDonnell said. “No matter how good you are at mental arithmetic, it gets pretty exhausting after 10 minutes. And right after that, we give them an attention task.”

The idea was to deplete participants’ attentional reserves before performing the standardized “attention network task” and walking around, which they do without their electronic devices or talking to anyone in class. of road. They are randomly selected to roam the less built-up portion of the arboretum along Red Butte Creek or the adjacent U Medical campus and parking lots. Both routes covered two miles with similar elevation gain.

“Participants who had walked in nature showed improvement in their executive attention on this task, whereas urban walkers did not. So we know that the environment you walk in is something unique,” McDonnell said. “We know that exercise also benefits leaders’ attention, so we want to make sure that both groups are getting comparable amounts of exercise.”

What sets this study apart from most existing research on the human-nature connection is its reliance on EEG data, as opposed to surveys and self-reports, which provide useful information but can be very subjective.

“This is probably one of the most rigorous studies in terms of controlling and making sure that it was exposure to Red Butte” that led to the observed cognitive effects, Strayer said .

McDonnell fitted each participant with a cap with holes to support an array of 32 electrodes that came into contact with the scalp using a special gel.

“It has electrodes placed over the entire surface of the scalp,” Strayer said. “It records really, really low voltages, but it’s a system of active electrodes that provides beautiful brain maps.”

The maps revealed three components of attention, alerting, orienting, and executive control.

Executive control occurs in the brain’s prefrontal cortex, an area essential for working memory, decision-making, problem solving, and coordinating disparate tasks.

“The kinds of things we do every day tend to heavily use these attentional networks of leaders,” Strayer said. “It’s important for concentration and most importantly, it’s an essential part of higher-order thinking.”

Although the results of the EEG and attention tasks did not show much difference in alertness and orientation between the garden walkers and those who walked on the asphalt, those who participated in the nature walk showed improved executive control.

McDonnell and Strayer hope the results can be refined to show what types of natural settings result in optimal cognitive benefits and what exposure is needed to help.

“If you understand something about what makes us healthier mentally and physically, then you could potentially design our cities to support that,” Strayer said.

The team is continuing their research in Red Butte, but is now examining how cell phone use affects garden walkers’ responses. Strayer is sometimes asked why he studies both distraction and attention, which he considers opposite sides of the same coin.

“That’s where the prefrontal cortex gets overloaded, overstimulated, and you make all sorts of dangerous mistakes when you’re multitasking while driving,” he said. “But the antidote to that is to be in a natural environment, leave the phone in your pocket, and then go out and hit the trails. The parts of the brain that have been overused during daily travel are restored. You see and think more clearly.”