For body and mind: Neuroscientist ties brain health to outdoors life

Outdoor activity is often associated with physical well-being.

Being in the natural world also plays a vital role in mental health, according to Dr. Michael Merzenich, professor emeritus at the University of California, San Francisco and a leading pioneer in brain plasticity research for nearly five decades.

When people are engaged in activities like hiking, Merzenich says, the brain is getting its own exercise, constantly assessing and reassessing the environment for everything from threats to making minute adjustments along an uneven hiking trail.

“One of the main things the brain is designed to do is it’s designed to detect and interpret surprise,” said Merzenich. “When a surprise occurs your brain basically goes into a momentary super-charged state. It pumps out a chemical called noradrenaline, and what it does is it amplifies activity in the brain, and the region that’s amplified relates to an area where you’re interpreting what you’re seeing or what you’re hearing.”

“We don’t problem solve so much as we look up answers to things. We’re changing the way our brains are exercised and that’s changing us.”— Dr. Michael Merzenich, University of California, San Francisco

Merzenich, a Kavli Laureate in Neuroscience and co-founder of Posit Science, a company that provides brain training software and services, said when the act of being surprised is simulated in the laboratory, the subjects are then able to learn at a faster rate.

“If I set them up with a task in that period, they are a faster learner,” he said. “It’s good for about an hour.”

Merzenich compared the effect on subjects to turning up the lights on a dimmer switch, and said the benefit begins to be sustained after two weeks of 15-minute sessions.

engage with environment

In the natural world, Merzenich said novel things and surprises trigger this super-charged state, but as people have built cities and more recently, turned their attention to digital devices, they are no longer getting the benefits of being engaged with their environment.

“Our brain is deprived a massive level of exercise by living in an artificial world. We’ve adjusted our local environment so that everything is predictable, we don’t have to think about anything,” said Merzenich.

“Common city life, you only see things in front of your nose and you no longer see things out in the world … you became very, very inadequate at detecting anything that’s surprising or novel. That’s really what we’re designed to do. That’s what our brains are designed to do, we’re designed to be masters of our physical environment, to be looking for the surprises in it that don’t fit, to be evaluating what they mean and what their value is to us. The natural world is just about the best possible way to find all of those surprises.”

He added that living in an “artificial world” has other negative consequences such as loss of field of vision.

“It’s not that it’s completely bad for us,” he said on living in cities or spending a great deal of time indoors. “In a sense, it’s just very unnatural, very distorted, and very limited. If you just look at the average 65 year old, they’ve lost about 40% of the world in front of them, they don’t see it. Anything close to the side of their vision, they don’t see it. By the time you’re 75, you’ve lost half of it.

“You’ve trained your vision to focus on the just ahead part of the world. Really, from the point of view of your brain, that’s very unnatural. That’s very different from the average individual 100 years ago.”


With the emergence of mobile devices, Merzenich said the effects are worsening, especially for children.

“There’s no question that the brain of the average little kid right now is vastly different from the brain of a kid even 20 years ago, because the brain basically is plastic, and it changes itself as a function of how it’s engaged,” said Merzenich. “What the child is engaging in is a lot of rule-based behavior, working in activities that are largely rule-based. The kid is doing things that they enjoy and are not valueless, but they’re not the real world, and increasingly we take a sort of artificial approach to life. We don’t problem solve so much as we look up answers to things. We’re changing the way our brains are exercised and that’s changing us.”

By being deprived of the unpredictability and novelty of natural settings, according to Merzenich, people begin to suffer from disorders such as depression and anxiety.

“Human survival was dependent on being an accurate, fast interpreter of the meanings of things,” he said. “Another way of putting that is, that it’s an important form of exercise. If I degrade that machinery, I go into clinical depression. If I enliven that machinery, I have a life that’s vital and bright. There’s real value in exercising the brain.”

In order to employ this mental form of exercise, Merzenich’s advice is simply to get outside and be engaged in one’s surroundings, whether it is at a park, on a hiking path or at the beach.

“I tell people try to be a little bit more like a child again,” he said. “There’s nothing quite so wonderful as being out on a forest path or being some place where everywhere you look there’s something really interesting — if you’re just open to it.”

Justin Scacco is a reporter for the Sierra Sun. Contact him at

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