Psychologists have long known there is good evidence that being in nature clears the mind and removes stress, that the sound of a rushing stream or the sight of a soaring mountain can help to bring people back to sanity.
There have been two competing theories why that should be the case but the notion appears to have gained support from research published in the journal Scientific Reports.
Attentional restoration theory argues that when we are in artificial environments there is too much to see and our brains become overstimulated, while in the natural world we are still stimulated but in a way that requires less direct, conscious, attention. Alternatively, stress recovery theory suggests that being in nature reduces the physiological stress mechanisms, including the fight or flight reaction.
Scientists from Brighton and Sussex Medical School tested the theories by exposing 17 people to sounds from natural and artificial environments while monitoring their brain and heart rate.
Stress recovery theory looked the better fit because parts of the brain responsible for fight or flight were being directly affected. However, the experiment would need to be repeated on a larger scale in a natural environment to be more confident of the results.