For most of us, the sounds of nails on a chalkboard can drive us crazy, right? However, for the most part, everyday sounds like rustling leaves don’t seem to ruffle us much.
But did you know that there are some folks, for whom certain sounds like crunching chips, slurping foods or the sounds of crackling can get them agitated and even angry?
If you happen to be one of them and you have wondered why you are supersensitive, don’t worry. You are not alone! The phenomenon that seems to trigger agitated responses is called misophonia and has triggered the interest of researchers.
Researchers at the Institute of Neuroscience at Newcastle University in England, stumbled on a strange reaction in some of their MRI (Magnetic Resonance Imaging – a medical procedure similar to X-ray) patients.
They observed that some of their patients reacted violently to the sound of noises during the procedure. This response seemed to be quite similar in signs and symptoms, such as an increase in heart rate and sometimes sweating.
‘Misophonia’ (hatred of sound) is a condition of selective sensitivity to sounds. Researchers were curious to learn more and developed a more in-depth study to look at reactions to different types of sounds. Three kinds of sounds that triggered such a strong response were studied – repetitive sounds like pen clicking, eating, breathing and drinking water; normally annoying sounds like screams; and neutral sounds such as the sound of the rain.
It Is All In The Brain!
Surprisingly, researchers found that those who suffered from misophonia have structural differences in the areas of their brains that deal with emotions. When researchers compared the brain activity, heart rates and skin responses of misophonic people to the three types of sounds, they noticed profuse sweating and increase in heart rates for the first type of sounds. The anxiety caused them great distress and many tried to get away from the situation.
Brain scans showed that the trigger sounds produced a large activity in the part of the brain called ‘anterior insula cortex’. This region is known to be involved with processing of emotions and is strongly connected to parts of the brain that is involved in recalling past experiences such as the hippocampus and amygdala. While all individuals react strongly to some sets of sounds or the other, people with misophonia seem to respond fairly aggressively to common every day sounds.
So what could the origin of misophonia? Nobody knows for sure. It could be a function of the unique brain structure of such individuals, or genetic defects, or a rewiring of the human brain from past experiences. It is a mystery for now and one that is sure to be studied in the future.