It’s no secret that our brains are wired to constantly process the sensory information we receive from our environment, even when we’re not actively paying attention to it. But did you know that this includes background noise? Researchers have found that the brain is hardwired to categorise and make sense of the sounds that surround us, no matter where our focus may be.
This new understanding of the brain’s abilities sheds light on how we process the world around us and could have important implications for fields such as psychology, neuroscience, and even urban planning. This is the finding of a research carried out at the University of Oslo.
“The brain always tries to utilise all kinds of information to understand what’s going on”, said Julian Fuhrer. He is a research fellow at RITMO Centre for Interdisciplinary Studies in Rhythm, Time and Motion.
In his research, Fuhrer has investigated how the brain even encodes patterns in the background while performing other tasks such as reading a book.
“The brain does this automatically. For example when you watch the sky and you suddenly realise that the clouds form shapes,” Fuhrer explained.
The study relied on a cutting-edge measurement technique called intracranial electroencephalography (iEEG), which involves placing electrodes directly on the brain.
Fuhrer’s access to unique iEEG data has provided a wealth of information about the electrical signals generated by the brain. These signals can be used to accurately capture and measure brain activity, even during sleep and coma.
Compared to traditional scalp electroencephalography (EEG), iEEG provides a much more accurate picture of brain activity due to its higher temporal resolution and its ability to measure signals from neurons that are very close to the point of contact.
“These recordings enabled us to provide new neurophysiological evidence to show that our brains continuously aim to systemize the immediate environment and regard even things we don’t pay any attention to. This evidence helps to understand how we perceive and how the respective underlying brain mechanisms are implemented,” explained Fuhrer.
Fuhrer and colleagues saw what happened in the brain when the patients concentrated on reading a book while wearing headphones where they were exposed to an uneven stream of tones.
“It turned out that even if the brain does not take the sound into account, it makes calculations based solely on the sound sequences. It looks for connections between sounds without attention being involved,” said Fuhrer.
The tones varied from, for example, high-frequency sounds to quieter sounds. The different tone types followed each other randomly and just occurred in the background. Nevertheless, the brain tried to systematise the tones by encoding patterns between them.
“We can see the brain’s response to each tone in the electrical signals and how it processes the various tones”.
“The brain does this automatically although there is no behavioural relevance in doing so. There is no sense to encode relations between these tones, but the brain does it anyway,” said Fuhrer.
Through their work with brain signals, Fuhrer and his colleagues developed a method for optimizing the use of such data. They hope this method will be useful for other researchers.
“The brain constantly processes, encodes information, stores information, and retrieves information from memory,” explained Fuhrer.
By treating brain activity from that perspective, he was able to distinguish different brain responses and identify where in the brain the various responses occurred.
“The results show that our method worked well, better than conventional methods,” he said.
The method will not necessarily turn the field of brain research upside down. “But I hope it establishes an approach in the researchers’ toolbox. A method which can be used to analyse neurophysiological data with the potential to get the most out of it,” concluded Fuhrer.