Do certain sounds – like people chewing or breathing – make you intensely angry and full of hate? Then you are probably suffering from a "devastating" condition called misophonia.
This condition, which affects so, so many, is the result of changes in the structure of the brain's frontal lobe when "trigger" sounds are heard. The result: an immediate – and intense – fight or flight feeling.
Sukhbinder Kumar, from Newcastle University, who found evidence of the condition, said: "For many people with misophonia, this will come as welcome news as for the first time we have demonstrated a difference in brain structure and function in sufferers.
"Patients with misophonia had strikingly similar clinical features and yet the syndrome is not recognised in any of the current clinical diagnostic schemes. This study demonstrates the critical brain changes as further evidence to convince a sceptical medical community that this is a genuine disorder."
His team studied brain scans of people who believe they suffer with misophonia, tracking the changes that take place when they were played neutral, unpleasant and trigger sounds. These included:
Rain, busy café, a kettle boiling – neutral sounds
Baby crying, a person screaming – unpleasant sounds
The sounds of breathing, eating – trigger sounds
Findings, published in Current Biology, showed a difference in the frontal lobe between the cerebral hemispheres with those who claim to suffer from the condition. This area is in the grey matter, buried in a fold at the side of the brain that is involved in processing emotions. Researchers also noticed people with misophonia had an increased heart rate and sweating when played trigger sounds.
"The commonplace nature of these sounds (often referred to as 'trigger sounds') makes misophonia a devastating disorder for sufferers and their families, and yet nothing is known about the underlying mechanism," researchers wrote. "Using functional and structural MRI coupled with physiological measurements, we demonstrate that misophonic subjects show specific trigger-sound-related responses in brain and body.
"Overall, our results show that misophonia is a disorder in which abnormal salience is attributed to particular sounds based on the abnormal activation and functional connectivity of the anterior insular cortex."
The Brain Basis for Misophonia, Current Biology
UCL's Tim Griffiths, an author of the study, said he hopes the study will "reassure suffers" that the condition is real and normal. "I was part of the sceptical community myself until we saw patients in the clinic and understood how strikingly similar the features are," he 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."
Kumar added: "My hope is to identify the brain signature of the trigger sounds –those signatures can be used for treatment such as for neuro-feedback for example, where people can self-regulate their reactions by looking at what kind of brain activity is being produced."