Most people who have?been students?can recognize?this: You have managed to put down your phone with all its?visual and audio?alerts?that try to tell you that?you're?missing out on something exciting. Now you will finally find peace of mind in the?study hall, concentrate on the syllabus, on what is important.??
And then?there is a?sound:??
Crack.?A carrot.??
And then:?
Sniffle.?A runny nose.?
Your concentration is broken and the only thing you hear is the sounds.??
Why is this happening? What happens when your attention?is drawn?to disturbing sounds??
“The sounds around us have different tempos, which we usually use to separate them and focus. But when an irregularity occurs in that tempo, the brain reacts by engaging a little more. It’s about perceiving possible threats,”?says Maja?Dyhre?Foldal.??
In her PhD thesis,?Foldal?investigated how the brain reacts to unexpected sounds.?What matters is?when?the sounds occur and what the brain is already familiar with, she believes.?
Different tempos help you?focus?
We distinguish between sounds all the time. Imagine a café. Music is playing in the background. Ten different conversations are taking place at the tables. Outside, a tram passes by. The barista stands behind the counter and asks what kind of coffee you want. The fact that you hear the question and can order your coffee with?ease,?is mainly thanks to two mechanisms in the brain:?
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Prediction: Using all the sounds that you have heard before, your brain builds a model for what different sound sources usually sound like.?
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Attention: You use?that?knowledge?and that?model to direct your focus?toward?what's?important.?
When you focus on the barista, her voice has a different tempo than the music playing in the background and the conversations around the tables.?
“Based on conversations you've had in the past and knowledge of how language works, the brain can control?your?attention?by?using tempo. This is how it processes the information in the conversation with the barista more efficiently – and ignores the other sounds,”?says?Foldal.??
The brain builds?brick?by?brick?
One of the explanations?why?we usually manage to focus on a sound source is that the brain has learned to distinguish what is?unimportant when it senses things.?
“We already have a lot of experience, so we don't have to re-sense everything every time. Usually one thing happens, and afterwards another thing happens, so instead of capturing all the information all the time, we just need to capture what’s new,”?Foldal?explains.?
The?brain processes the?new information?and uses it?to improve what Foldal regards as a model undergoing continuous development.?But?although you may have experienced it before, you are?for example?not prepared for?a serious conversation?being?interrupted by a notification from your phone, a siren outside your window, or a fire alarm.??
“We have a good understanding of what is going on around us when we sit and talk. If a fire alarm goes off, it differs from what we expect, and it becomes very important to investigate what the sound means.”?
A?break in rhythm results in higher brain activity?
To measure what?happens in the brain when we?are exposed?to unexpected sounds, Foldal conducted experiments using the Electroencephalography (EEG) method, which measures electrical activity in the brain and allows the researcher to measure exactly when inf