Tag Archives: synesthesia

Misophonia: Common sounds are all the rage

Click click click.

“Dear GOD, why does she keep doing that? Doesn’t she know how irritating that is? Has she no respect for the rest of us trying to work? Is she intentionally trying to piss me off?!”

Your blood pressure rises as you bite your lip, suppressing the urge to verbalize this inner dialogue. You take several deep breaths to assuage the flood of anxiety. The anger and stress slowly dissolve, replaced by shame as you realize just how irrational this emotional response was. After all, your coworker was simply … clicking her pen.

Loud-noises

For most of us, sounds such as pen-clicking, chewing or whistling are everyday elements of a neutral auditory landscape that go largely unnoticed. But for a small portion of the population, such common sounds evoke extreme rage, disgust or anxiety. The first such cases were documented just over a decade ago, when the condition was coined misophonia, literally “hatred of sound”. Since then, thousands of self-diagnosed misophonics have sought comfort and advice from online support groups. Misophonia is gaining increasing attention by psychiatrists who believe it should be recognized as an official psychiatric disorder 1 and neuroscientists curious about how nervous system dysfunction may contribute to the condition. As a first step, a team of psychologists sought to better characterize misophonia in their study recently published in Frontiers in Human Neuroscience 2.

Misophoni-who?

The researchers conducted a series of extensive interviews with eleven self-reported misophonics to characterize their trigger sounds, environmental features that exacerbate their reactions, and personal thoughts and coping strategies. Despite the small sample size and the somewhat anecdotal nature of the data, the study reports some interesting common threads. Most participants reported that symptoms first appeared in childhood and either continued or worsened over the years. Chances are, just today you’ve probably made some of the very sounds misophonics report as most maddening, including eating or chewing, pen clicking, footsteps, finger tapping or whistling. And depending on who you are, your innocent walk down the hall or your chipper whistle may have sent a nearby misophonic into a horrified rage; 82% claimed that their discomfort is only set off by certain people, while none were bothered by making the sounds themselves. Although the victims of such noxious sounds may not outwardly display their horror, internally they’re feeling intense anxiety, anger, irritation or physical pressure, thinking that your sounds are rude or disgusting, and experiencing high blood pressure or a racing heart rate. In fact, underneath their blank expression, they just might be thinking … (yup. These were actual thoughts reported by study participants):

“I want to punch this person”
“I hate this person”
“Would you shut up?”

But don’t dismiss misophonia as an extreme case of hateful intolerance. Misophonics are acutely aware that they focus abnormally on sounds. Their agony can be so extreme that it forces them to avoid certain social situations and can even elicit suicidal thoughts. Their self-directed thoughts clearly reflect this inner struggle:

“Why am I like this?”
“I envy people who aren’t bothered by sounds”

Hot and bothered

Might misophonics simply be a crew of melodramatic hypochondriacs? To determine whether participants actually demonstrate physical signs of “sound hate”, the researchers measured the skin conductance reponse (fancy term for sweat production) to a variety of sounds and images. To no surprise, the misophonics reported greater discomfort than controls to sounds but not to images. Justifying their claims, they also produced a greater skin conductance response than controls to sounds than images, and this reponse was positively correlated with subjective aversion to sounds.

The misophonic brain

But sweat can tell only so much about a disorder that is likely neurological in origin. To understand why misophonia occurs, in addition to what it is, scientists will need to look beyond skin-deep, into the brain. To date, no research has directly studied the neurobiological basis of misophonia, although testable hypotheses are in the works. One prevailing theory has emerged from the similarities between misophonia and another intriguing condition that has long fascinated scientists – synesthesia. synesthesiaMuch as misophonics abnormally associate sounds with intense emotions, synesthetes experience aberrant associations between sensations; for example, associating letters with colors, or months with spatial positions. It’s believed that this atypical sensory integration arises from enhanced interactions between the brain’s sensory networks. In support of this idea, neuroimaging studies have shown activation of the color-selective visual area V4 when synesthetes hear words 3, and increased structural connectivity between implicated sensory regions 4. If misophonia arises from similar processes, it might be generated from excessive cross-talk between the brain’s auditory and limbic systems. This is an enticing theory indeed, but it is just a theory. The obvious next step is to test whether, in fact, misophonics abnormally activate limbic regions in response to trigger sounds, or show increased connectivity between limbic structures and auditory cortex.

Until we better understand the disorder, why not keep those closet misophonics in mind at your next lunch? Chomp your sandwhich a tad quieter and you just might save someone’s sanity.

References

1. Schroder A et al. 2013. Misophonia: Diagnostic criteria for a new psychiatric disorder. PLoS One. 8.
2. Edelstein M et al. 2013. Misophonia: physiological investigations and case descriptions. Front Hum Neurosci. 7:296.
3. Nunn JA et al. 2002. Functional magnetic resonance imaging of synesthesia: activation of V4/V8 by spoken words. Nat Neuro. 5:371-5.
4. Zamm A et al. 2013. Pathways to seeing music: enhanced structural connectivity in colored-music synesthesia. Neuroimage. 74:359-66.

ResearchBlogging.org
Edelstein M, Brang D, Rouw R, & Ramachandran VS (2013). Misophonia: physiological investigations and case descriptions. Frontiers in human neuroscience, 7 PMID: 23805089

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