Natural sounds positively affect our heart and brain, according to research.
Whether it’s a ramble through woods or the ebb and flow of waves on the seashore, nature has a calming effect on us, and scientists have been investigating what’s happening in the body when people hear natural sounds.
In a lab-based experiment researchers from the University of Sussex in England teamed up with an audio-visual artist who records nature and artificial sounds
MRI scans recorded the brain activity of 17 healthy participants who performed a mind-wandering task listening to a background recording of a familiar nature or artificial sound. At the same time minute alterations in heart rate were monitored to measure autonomic nervous system activity.
The results published online in the journal Scientific Reports found the default mode network in the brain – a collection of regions activated during rest – responded differently to the artificial and natural sounds.
The natural sounds produced brain patterns indicating an outward-directed focus of attention, meaning attention focuses on what’s happening in the environment instead of inside the head.
Conversely, artificial sounds produced brain patterns indicating an inward focus of attention or focusing on what’s happening inside our body, such as feelings and thoughts: this brain pattern is often seen in conditions where people worry and ruminate a lot, such as anxiety, depression and post-traumatic stress disorder.
Listening to natural sounds also slowed the sympathetic nervous system which triggers stress responses, whereas the parasympathetic nervous system which helps the body relax was increased.
In addition, reaction times were slower when the participants listened to artificial sounds, indicating that listening to the artificial sounds was associated with a poorer attention span.
The response strength depended on the participants’ baseline: the people most stressed at the start of the experiment seemed to benefit the most from listening to the natural sounds. In contrast, the relaxed people at baseline showed slight increases in stress after listening to the natural sounds.
“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. 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,” said lead author Dr Cassandra Gould van Praag in a news release.
Gould van Praag, C. D. et al. Mind-wandering and alterations to default mode network connectivity when listening to naturalistic versus artificial sounds. Sci. Rep. 7, 45273; doi: 10.1038/srep45273 (2017).