If you’ve ever sat across the table from someone and felt angry, anxious or even homicidal at the sounds made while your dining partner is eating or drinking, you’re not alone. The term misophonia (which translated from Latin literally means “hatred of sound”) was first coined in 2002 at Emory University by researchers there who were investigating other auditory conditions and how they impacted the brain. Since then there has been more awareness and research on the phenomenon, but there is still no official recognition of it as a disorder or condition. Some believe it’s related to obsessive-compulsive disorder (OCD), while others think it’s a problem with auditory and sensory processing. The most recent research on it however, might finally be the proof needed to classify the feelings some have when they hear sounds of chewing, slurping or crunching as actual disease.
A team of neuroscientists at Newcastle University in the UK have shown, via brain imaging, a difference in brain structure for people who experience strong emotions when hearing “trigger sounds” like gum snapping, chewing or even repetitive sounds like pens clicking.
Dr. Sukhbinder Kumar from the Institute of Neuroscience at Newcastle University and the Wellcome Centre for NeuroImaging at University College London (UCL) led the research, which was supported by Wellcome. He explained, “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. Patients with misophonia had strikingly similar clinical features and yet the syndrome is not recognized in any of the current clinical diagnostic schemes. This study demonstrates the critical brain changes as further evidence to convince a skeptical medical community that this is a genuine disorder.”
The team used MRI scans both functional (fMRI) and traditional to observe brain activity and structure in 20 study participants with misophonia and 22 participants who reported no issues with certain sounds. In those who reported feelings of anger, fear and anxiety at hearing certain sounds, their brain structure was decidedly different from those who were not misophonic especially in the frontal lobe between the cerebral hemispheres and in the grey matter of the ventromedial prefrontal cortex (vmPFC).
In fMRI scans, each participant was asked to listen to three types of sounds. Neutral sounds like a busy restaurant, a rainstorm or a boiling teakettle, unpleasant sounds, i.e. sounds that anyone would find distressing, like a person screaming or a fussy baby crying and sounds that misophonics say trigger their feelings of anger like the sound of someone eating, chewing or breathing. The scans looked at connectivity between two areas of the brain, the frontal-lobe area and an area called the anterior insular cortex (AIC). The AIC is a part of the brain that researchers know is involved in processing emotions and reacting to stimuli in the environment. When the trigger sounds were played, the activity in both of these areas spiked for the misophonic group. In the typical subjects there was a spike in the AIC, but a dip in activity in the frontal lobe. The researchers described this as the brain going into “overdrive” in people who suffer from misophonia.
Tim Griffiths, Professor of Cognitive Neurology at Newcastle University and UCL and co-author of the research stated, “I hope this will reassure sufferers. I was part of the skeptical community myself until we saw patients in the clinic and understood how strikingly similar the features are. We now have evidence to establish the basis for the disorder through the differences in brain control mechanism in misophonia. This will suggest therapeutic manipulations and encourage a search for similar mechanisms in other conditions associated with abnormal emotional reactions.” The video below shows participants and their reactions to certain sounds, take a look.