Why Does The Sound of Chewing Make Some People Panic?
Wednesday, August 21, 2013
Aired 8/21/13 on KPBS News.
For some people, repetitive noises like gum-chewing and foot-tapping are much more than annoying. They can evoke feelings of uncontrollable panic and rage, and researchers have only just begun to study what's causing this unusual condition.
Gum-chewing, foot-tapping, loud typing. Good luck finding anyone who enjoys these sounds.
But for some people, these kinds of repetitive noises are much more than annoying. They can evoke feelings of uncontrollable panic and rage, and researchers have only just begun to study what's causing this unusual (and as-of-yet unrecognized) condition.
Alesia Poynter is married to a pastor. Some might "tsk-tsk" the sight of a pastor's wife walking out in the middle of church, but sometimes she just has to.
"It can even be someone praying," she said. "The sound of their 'sssss' — you know, the 's' — will make me crazy."
Poynter has something called misophonia, which literally means the "hatred of sound." It's not well understood at this point, but Poynter knows that if she hears certain trigger noises, she'll become extremely agitated.
"I just get really panicked, upset," she said. "I start looking at people, giving them dirty looks. I now wear headphones, or I just have to leave."
People with misophonia are each set off by different sounds, but most of them say they can't stand chewing. That's why when Poynter pictures dinnertime in her Glendora household, she usually sees one empty chair at the table.
"It looks like me taking my food and eating in my room, pretty much," she said.
Poynter's misophonia follows her everywhere, from home to the office to vacations, but she didn't even know what term to use for her problem until a few years ago. That's because misophonia is still such a new concept, even people who have it might not know about it.
"In terms of empirical research that has been conducted, I only know of one other study that was published earlier this year," said Miren Edelstein, a doctoral student in psychology at UC San Diego. In a paper published in Frontiers in Neuroscience, she and her colleagues confirmed that, yes, misophonia is very much real. And it's a lot worse than simple annoyance at rude noises.
The researchers brought a small group of people into the lab for an experiment. Some of them had misophonia; some didn't. Edelstein hooked each of them up to a machine that measures the body's fight-or-flight response. Then she showed them some videos.
In these videos, people aggressively chew apples, furiously click pens and munch on potato chips. The charts taken from people with misophonia explain a lot. The lines indicating fight-or-flight response look flat and calm at first, but when the videos kick in, they shoot right up.
"This would be an example of a pretty large response," Edelstein said.
Why do we see this response in people who say they have misophonia but not in typical individuals? Put another way, what's the underlying cause of this condition? It's still way too early to tell, but Edelstein and her colleagues have a hypothesis.
"It could be due to an enhanced connectivity between the auditory cortex of the brain—where sounds are processed—and the limbic system, basically where your body's emotional and fight-or-flight response are processed," Edelstein explains.
Synesthesia causes people to conflate certain perceptions with other unrelated perceptions. So for instance, synesthetes might experience the number three in terms of the color red. Or they might touch a sheet of sandpaper and automatically start to feel guilty.
People with this condition tend to have an unusually high number of neural connections between certain parts of their brains. Maybe people with misophonia also have more connections, in this case linking the sound-associated part of their brain to the primal emotion-associated region.
The key word here is "maybe." It's going to take lots of brain scanning before we can say anything even remotely conclusive about misophonia, but for those living with it, the fact that scientists are looking into their condition at all is encouraging.
"Now, disorders and things like bipolar and [obsessive compulsive disorder] are just common talk," Poynter said. "Maybe one day misophonia will be understood like that, and not just this weird quirky thing that some of us say we have."
Misophonia is not currently recognized in the DSM, the book psychiatrists use to diagnose mental disorders, and that means there are no official treatments sanctioned by the American Psychiatric Association.
But many people suffering from misophonia have found their own ways of mitigating their condition. One of them is San Diego lawyer Heidi Salerno. She turned to a somewhat controversial yet increasingly popular and often effective therapy called 'neurofeedback.'
It essentially trains people to modulate the electrical activity in their brains. Salerno said neurofeedback helped her just about beat misophonia.
"Things just stopped bothering me," she said, "until almost all but one of my triggers was gone."
But neurofeedback doesn't work for everyone. And it's an expensive therapy that most health insurance plans don't cover.
Until researchers find a better way to treat the condition, people with misophonia say public awareness would make their lives a little easier. Then at least they wouldn't have to spend so much time explaining why people really need to stop tapping their feet and snapping their gum.