According to scientists, supersensitized brain connections may be to blame for sounds, such as chewing, triggering people’s misophonia.
Does the sound of people chewing, or drinking make you want to pull out your hair? Do you feel anxious or intense anger on hearing loud breathing? Well, chances are you’re probably suffering from a condition called misophonia. It affects around 6% to 20% of people across the globe. Those who suffer from misophonia often feel intense negative emotions on hearing everyday sounds such as chewing, swallowing, and even breathing. But what causes this hatred of sound?
Now, for the first time, a team of researchers at Newcastle University have discovered the mechanism behind this disorder. They published their findings in the Journal of Neuroscience.
The team recruited 17 participants with misophonia and 20 control subjects. They conducted functional magnetic resonance imaging (MRI) scans on the brains of the participants. The scans were taken in a resting state and while they listened to certain sounds. Participants listened to three kind of sounds: trigger sounds that evoke a reaction in people with misophonia, aversive sounds that both groups find unpleasant, and neutral sounds.
Our findings indicate that for people with misophonia there is an abnormal communication between the auditory and motor brain regions – you could describe it as a supersensitised connection. This is the first time such a connection in the brain has been identified for the condition.
Dr Sukhbinder Kumar, study author
Supersensitized Brain Connection
When exposed to the trigger sounds, the auditory cortex (hearing centre) of the brain did not show any differences in both groups. However, misophonia sufferers had increased communication between the auditory cortex and the part of the brain responsible for orofacial movements. Moreover, the orofacial motor area showed stronger activation in those suffering from misophonia, especially in response to trigger sounds.
We also found a similar pattern of communication between the visual and motor regions, which reflects that misophonia can also occur when triggered by something visual
Dr Sukhbinder Kumar, study author
According to the study authors, trigger sounds cause involuntary activation of a ‘mirror system’ in people suffering from the disorder. This leads people to feel as if they themselves are performing the action and producing the sound. Thus, making them feel like the sound is intruding into their bodies and is out of their control.
Professor Tim Griffiths, lead author of the study, believes the study opens new doors for treatment of misophonia. Future therapies should focus on not only the sound centers in the brain, but also motor areas.
Reference:
Kumar, S., Dheerendra, P., Erfanian, M., Benzaquén, E., Sedley, W., Gander, P. E., Lad, M., Bamiou, D. E., & Griffiths, T. D. (2021). The motor basis for misophonia. The Journal of Neuroscience. https://doi.org/10.1523/jneurosci.0261-21.2021
