If hearing a specific noise, such as the sound of someone eating close to you, is enough to push you to your limits, it could be a sign of a genuine illness: misophonia. Misophonia is not very well known as it has been described only relatively recently, although we now know a little more about it thanks to brain scanning techniques.
A study recently published in Current Biology explains a little more about misophonia, which is an inability to tolerate certain sounds. We still do not know very much about this illness, which was first described in the early 2000s, and to date only two case studies have been published on the subject. One of these studies showed that when a misophonia sufferer is faced with a sound they find intolerable, the fight or flight response is physiologically activated, which is in fact a survival mechanism.
This new study was co-signed by Olana Tansley-Hancock, a specialist in neurobiology and general psychiatric problems, who is herself affected by misophonia. From the age of 7, the sound of other people chewing was so intolerable that she had to eat her meals alone. Growing up, things only got worse and the torture extended to other noises such as paper being crumpled or the sound of someone typing on a computer. Her misophonia was wrongly put down to a phobia.
The new study, led by Sukhbinder Kumar of Newcastle University in England, was conducted on 20 people affected with severe misophonia, who were compared with 22 people who did not suffer from the illness. The brain activity of all participants was monitored while they were exposed to neutral sounds, unpleasant sounds like babies crying, and the sounds that are typically involved in misophonia, such as chewing or breathing.
In the conclusions of the study, it was explained that all participants reacted in the same way to the first two types of sounds -neutral and unpleasant. Upon listening to the trigger sounds, the people with misophonia presented with fight or flight responses, significantly increased heart rate and an increase in skin conductivity. Brain scans revealed peaks of brain activity in the anterior insular cortex, a region known to be implicated in attention mechanisms.
It is a malfunction in this area of the brain that makes sufferers associate relatively innocuous noises with disproportionate emotional reactions. While they listened to these noises, this brain area was also establishing very dense connections with other brain areas which regulate memory and emotions.