If the sound of a co-worker repeatedly clicking his pen can send you into a flaming furor, take heart: You’re not being hypersensitive, and you’re not alone. Neurologists in the UK have spotted physical differences in the brains of people with this sound-related rage, although whether these differences are the cause or the result of the disorder remains to be seen. The scientists published their findings in the journal Current Biology.
The technical term for that noise-triggered irritation and rage is misophonia (“hatred of sound”). People who have it experience uncontrollable and intense negative emotions after hearing certain repetitive noises like chewing, lip-smacking, pen-clicking, and foot-tapping.
It’s a relatively new concept within the medical community, although people have been complaining of symptoms for a long time. To those who’ve never experienced misophonia, it may sound silly or made-up—which is what many doctors have concluded. Others have categorized it as a form of anxiety or obsessive-compulsive disorder.
The authors of the current paper wondered if the problem might not be psychological but neurological. They recruited 20 British adults with misophonia and 22 without, and gave them all questionnaires to gauge their responses to various noises. Then they put each participant inside MRI and fMRI machines and played them all sorts of noises, including the benign (a kettle whistling, rain), the universally unpleasant (a baby crying, someone screaming), and common misophonia triggers (breathing, chewing).
As the researchers suspected, the results for the two groups looked very different. People with misophonia had more myelin, or insulation, around the gray matter in their prefrontal cortex. They also showed abnormal connections between this cortex and the anterior insular cortex, which is involved in processing information and emotions.
Hearing the trigger noises caused a spike in activity in both cortices for people with misophonia. For people without it, activity only increased in the prefrontal cortex. The trigger sounds also provoked a clear stress response in people with misophonia. Their heart rates increased and they began sweating.
Lead researcher Sukhbinder Kumar is a neuroscientist at Newcastle University and University College London. He says his team’s research should reassure people with misophonia and validate the condition’s existence to their doctors.
“Patients with misophonia had strikingly similar clinical features, and yet the syndrome is not recognized in any of the current clinical diagnostic schemes,” he said in a statement. “This study demonstrates the critical brain changes as further evidence to convince a skeptical medical community that this is a genuine disorder.”
It also suggests a possible way of treating the condition. “My hope is to identify the brain signature of the trigger sounds,” Kumar said. “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.”