Olana Tansley-Hancock knows misophonia's symptoms only too well. From the age of about 7 or 8, she experienced feelings of rage and discomfort whenever she heard the sound of other people eating. By adolescence, she was eating many of her meals alone. As time wore on, many more sounds would trigger her misophonia. Rustling papers and tapping toes on train journeys constantly forced her to change seats and carriages. Clacking keyboards in the office meant she was always making excuses to leave the room.
Finally, she went to a doctor for help. "I got laughed at," she says.
"People who suffer from misophonia often have to make adjustments to their lives, just to function," says Miren Edelstein at the University of California, San Diego. "Misophonia seems so odd that it's difficult to appreciate how disabling it can be," says her colleague, V. S. Ramachandran.
The condition was first given the name misophonia in 2000, but until 2013, there had only been two case studies published. More recently, clear evidence has emerged that misophonia isn't a symptom of other conditions, such as obsessive compulsive disorder, nor is it a matter of being oversensitive to other people's bad manners.
Some studies, including work by Ramachandran and Edelstein, have found that trigger sounds spur a full fight-or-flight response in people with misophonia.
Now it seems there may be a neurological explanation for this. Sukhbinder Kumar and his team at Newcastle University, UK, carried out a series of tests on 20 volunteers with a severe form of misophonia, as well as 22 people who don't have it. Both groups listened to neutral noises, like the sound of rain; unpleasant sounds, such as a baby crying; and sounds that were triggers for the misophonics, such as chewing or breathing noises.
While both groups reacted to the neutral and unpleasant sounds in a similar way, the misophonic group experienced increased heart rates and skin conductance -- both signs of the body's fight-or-flight response -- when they heard trigger sounds.
Brain scans revealed that the misophonics had heightened activity in the anterior insular cortex (AIC), an area known to play a central role in the system that determines which things we should pay attention to. When the trigger sounds were played, there was not only more activity in this region but also abnormally high levels of connectivity to other regions. "The AIC is hyperconnected to structures that are involved in emotion regulating and memory," says Kumar.
There was also increased connectivity to regions involved in the default mode network, which helps summon memories and processes internally generated thoughts. In misophonics, one of these regions, called the ventromedial prefrontal cortex (vmPFC), had a higher level of myelination -- fatty sheaths that surround nerve cells and help conduct their signals -- which may explain the greater connectivity.
Together, these findings suggest that the systems that normally influence what we pay attention to, and respond to emotionally, are disrupted in people with misophonia.
"I am hopeful that, in addition to providing powerful validation to sufferers of misophonia, this study will inspire a new wave of research on this topic," says Edelstein.
The hope is that such research will ultimately help people like Tansley-Hancock cope with the condition, or even lead to treatments for it. Tansley-Hancock is herself a neuroscientist, and worked with Kumar to develop the tests for the study. "I had the triggers played at me over and over," she says -- something that can feel like torture to someone with misophonia. "It was all in the name of science."
Tansley-Hancock tried cognitive behavioural therapy, which required her to listen to recordings of trigger noises. Unfortunately, it actually made her more sensitive to a wider range of triggers. To cope, she does her best to avoid triggers, wears earplugs when she knows she'll be exposed, and at mealtimes she tries to sync her bites with other people's.