Here is another one: Why parks matter: Nature improves your brain
Exposure to nature improves concentration and problem solving. It reduces stress and increases feelings of empathy. One study found that hospital patients with bedside views of trees recovered faster, needed less pain medication and had fewer complications after surgery. Even simple things like gardening, hiking, jogging or walking the dog are good for our mental and physical health.
In a test of creative reasoning, researchers found that people score 50% higher on creativity and problem-solving tests after unplugging and spending four days outside.
(I wish that they had linked to the study.)
More info here: This Is Your Brain on Nature.
In some countries governments are promoting nature experiences as a public health policy. In Finland, a country that struggles with high rates of depression, alcoholism, and suicide, government-funded researchers asked thousands of people to rate their moods and stress levels after visiting both natural and urban areas. Based on that study and others, Professor Liisa Tyrväinen and her team at the Natural Resources Institute Finland recommend a minimum nature dose of five hours a month—several short visits a week—to ward off the blues. “A 40- to 50-minute walk seems to be enough for physiological changes and mood changes and probably for attention,” says Kalevi Korpela, a professor of psychology at the University of Tampere. He has helped design a half dozen “power trails” that encourage walking, mindfulness, and reflection. Signs on them say things like, “Squat down and touch a plant.”