Scientists are getting closer to unlocking the secrets behind a common condition marked by hypersensitive reactions to everyday sounds, like breathing or chewing. Misophonia, meaning "hatred of sounds" and which affects up to 20% of people, has long been thought to be a disorder of sound emotion processing, in which certain sounds trigger intense negative emotions, like anger, anxiety, and disgust. But Newcastle University researchers say they've come up with "an alternative but complementary perspective" that focuses not so much on the sounds but the action of the person making them. Realizing that many trigger sounds come from moving the face or mouth, researchers theorized that the brain's mirror neuron system related to orofacial movements was hyperactivated in sufferers, per the Guardian. This system is often activated when a person is processing the movements of others.
Brain scans showed misophonia sufferers had "abnormal communication" between the brain's visual and auditory cortexes and the premotor cortex, which controls the mouth and throat movement, per Sky News. "What we are suggesting is that in misophonia the trigger sound activates the motor area even though the person is only listening to the sound," Dr. Sukhbinder Kumar, lead author of the study published Friday in the Journal of Neuroscience, tells the Guardian. "It makes them feel like the sounds are intruding into them." "Misophonia is therefore not an abreaction to sounds, per se, but a manifestation of activity in parts of the motor system involved in producing those sounds," per the study. Kumar says giving in to an urge to mimic the action might lessen a sufferer's symptoms. Going forward, therapies "should target the brain representation of movement" rather than sounds, researchers add. (Kumar previously linked misophonia to memory.)