- Naturalistic sounds and green environments have been demonstrated to promote relaxation and wellbeing.
- When listening to natural sounds, the brain connectivity reflected an outward-directed focus of attention.
- The restorative effects of naturalistic stimuli, that is, the ability of nature exposure promotes recovery from physiological or psychological stress.
We tend to feel relaxed when we take a walk by the river or when the wind blows gently. There is scientific proof behind this 'nature's relaxing technique'.
The team of researchers found that activity in the default mode network of the brain (a collection of areas which are active when we are resting) was different depending on the sounds playing in the background.
Playing natural sounds affects the bodily systems that control the flight-or-fright and rest-digest autonomic nervous systems (associated with relaxation of the body), with associated effects in the resting activity of the brain, the findings published in the journal Scientific Reports showed.
In collaboration with audio visual artist Mark Ware, the team at BSMS conducted an experiment where participants listened to sounds recorded from natural and artificial environments, while their brain activity was measured in an MRI scanner.
"We are all familiar with the feeling of relaxation and 'switching-off' which comes from a walk in the countryside, and now we have evidence from the brain and the body which helps us understand this effect," said led study author Cassandra Gould van Praag from the Brighton and Sussex Medical School (BSMS) in England.
"This has been an exciting collaboration between artists and scientists, and it has produced results which may have a real-world impact, particularly for people who are experiencing high levels of stress," she said.
The autonomic nervous system activity of the participants was monitored via minute changes in heart rate. The team found that activity in the default mode network of the brain (a collection of areas which are active when we are resting) was different depending on the sounds playing in the background.
When listening to natural sounds, the brain connectivity reflected an outward-directed focus of attention. But when listening to artificial sounds, the brain connectivity reflected an inward-directed focus of attention similar to states observed in anxiety, post-traumatic stress disorder and depression.
There was also an increase in rest-digest nervous system activity (associated with relaxation of the body) when listening to natural compared with artificial sounds, and better performance in an external attentional monitoring task.
Nervous system results also changed depending on which sounds were heard, with natural sounds generally inducing a more relaxed state and artificial sounds inducing a more elevated, anxious state.
The nervous system changes were biggest for those who were most stressed when they started the study (interestingly, some people who started the study in a very relaxed state had an elevated reaction even to natural sounds).
This was a complex study in terms of interpretation, and there are probably some gray areas to resolve. But beyond what just this research can tell us, the results add to a growing library of science reinforcing how vital it is to get outside. Carving out opportunities in our hurried days to take a walk or bike ride, or just sit in a park at lunch, is the ideal counterbalance for our anxiety-generating organizations, offices and interactions.
- Hugo D. Critchley et al. Mind-wandering and alterations to default mode network connectivity when listening to naturalistic versus artificial sounds, Scientific Reports (2017) http:www.nature.com/articles/srep45273.