In this series, we dig into our strange phobias, fixations, and neuroses, and ask ourselves — Is This Normal?
I love my little sister. I really do. But she has an adenoid problem, which means her nose is blocked a lot. The consequence of this, is that when she eats something, her chewing and breathing, is very, very loud. The sounds that come from her make me want to tear my hair out. It’s become a family joke, now, that no one can make ‘mouth sounds’ waround me, especially my sister, whom I have politely asked to please stop breathing on more than one occasion.
Mouth sounds have always bothered me, making me irritable and irrationally angry — and I could never explain why, until I started digging on the internet. Turns out, it’s uncommon, but not abnormal.
‘Misophonia,’ a termed coined by researchers Margaret and Pawel Jastreboff in 2002, refers to a disorder where people are selectively sensitive to certain sounds. These sounds act as specific triggers — lip smacking, breathing, chewing, typing, etc. — of reactions that range from mild irritation, to rage and even physical aggression. Researchers are still studying this disorder, with some studies finding links between misophonia and post-traumatic stress disorder, obsessive compulsive disorder, depression, and anxiety.
Although scientists have been skeptical about treating this as a disorder in its own right, in 2017, Sukhbinder Kumar, PhD, and his team at Newcastle University, UK, found proof that the emotional responses triggered by sounds for those experiencing misophonia reflect changes in the brain’s frontal lobe. Running a series of tests on 20 people who appeared to have misophonia, and 22 who did not, Kumar and his team made both groups listen to a series of noises that were either neutral, like the sound of rain; unpleasant, like a baby crying; and triggers for misophonics, like chewing or breathing noises.
While both groups reacted similarly to the pleasant and unpleasant sounds, people with misophonia showed a marked difference in response when they heard the trigger sounds: comparatively, the group experienced an increase in heart rate and increase in skin conductance.
Kumar and his team studied brain scans of all the participants, and noted misophonics also responded to the trigger sounds with heightened activity in certain areas of the brain, including the anterior insular cortex (AIC), which helps us decide what to focus our attention on.
“The AIC is hyper-connected to structures that are involved in emotion regulating and memory,” said Kumar. These areas include the ventromedial prefrontal cortex (vmPFC), hippocampus, and amygdala. Misophonics’ brains also showed thicker insulating myelin sheaths in their vmPFC, which helps nerves carry messages faster. All of this basically means that those with misophonia have brains that are hyper-alert to particular sounds, and respond with more efficient coordination between regions that control emotion, memory, and the ‘fight or flight’ response.
“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,” said Kumar. “This study demonstrates the critical brain changes as further evidence to convince a skeptical medical community that this is a genuine disorder.” And it’s totally normal.
