Sound of people chewing drives you up the wall? We know why

Research suggests it may be due to brain condition called misophonia

LONDON: Ever wondered why the sound of people chewing food, breathing or the repeated clicking of a pen can irritate you so much? It may be because of an abnormality in your emotional control mechanism which causes the brain to go into overdrive upon hearing such triggers, claim researchers.



Recent findings showed that the brains of people with this condition – known as misophonia or hatred of trigger sounds – have a physical difference in the frontal lobe, between the cerebral hemispheres, with higher myelination in the grey matter of the ventromedial prefrontal cortex.
"For many people with misophonia...for the first time, we have demonstrated a difference in brain structure and function in sufferers," said Sukhbinder Kumar of Newcastle University.

Further, the study, published in the journal Current Biology, also showed abnormal connections between this frontal-lobe and an area called the anterior insular cortex (AIC) – known to be involved in processing emotions and integrating signals both from the body and outside world.

In misophonic participants, the trigger sounds increased activity in both brain areas, while in normal participants, the increase was seen only in the AIC, not in the frontal area. This reflects an abnormality of a control mechanism between the frontal lobe and AIC, the researchers said.



"We now have evidence to establish the basis for the disorder through the differences in brain control mechanism in misophonia. This will suggest therapeutic manipulations and encourage a search for similar mechanisms in other conditions associated with abnormal emotional reactions," added Tim Griffiths, a professor at the university.

The trigger sound was also found to evoke a heightened physiological response with increased heart rate and sweating in people with misophonia, the researchers noted.

Have something to add to the story? Share it in the comments below.