Misophonia — responding to daily sounds with intense anger and anxiousness — is connected with stronger connections among each the auditory and visual cortex, as nicely as the location of the brain connected with orofacial movements, according to a current study to be published in the Journal of Neuroscience.
Sounds that come from facial movements, such as consuming, drinking, and chewing, ordinarily trigger anger in individuals with misophonia.
The researchers analyzed resting state fMRI connectivity in 16 ladies with misophonia and 17 controls. The researchers captured 10 minutes of resting state fMRI information. The researchers also applied outcomes from a earlier misophonia fMRI study that measured evoked-sound response in 20 ladies with misophonia and a handle group of 22, age- and sex-matched.
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The fMRI information evaluation showed misophonia is characterized by the following:
- Increased resting-state functional connectivity among the orofacial motor location and each the auditory and visual cortex.
- Increased functional connectivity among the auditory cortex and orofacial motor locations in response to all kinds of sound.
- Increased activation of the orofacial motor location in response to trigger sounds. Specifically, activation of the orofacial motor location increases in proportion to the misophonic distress. There was no distinction from the handle group in the activation of auditory cortex to trigger sounds and other sounds.
- Increased resting-state functional connectivity among vPMC (ventral pre-motor cortex) containing the orofacial motor location and insula in the resting state.
The researchers also located that “spontaneous fluctuations in auditory/visual cortex and the orofacial motor cortex are synchronized to a greater extent in the misophonia group compared to the control group.” This stronger connection implies the orofacial motor cortex is “primed to respond” in individuals with misophonia.
This study had some limitations. The researchers stated that fMRI measurements are as well “coarse” to reveal the workings of single neurons, which implies their proof is indirect. Also, debate remains more than to what extent misophonia can be explained by other problems.
Misophonia is ordinarily characterized as a “disorder of sound emotion processing.” This study suggests “an alternative but complementary perspective on misophonia that emphasizes the action of the trigger-person rather than the sounds which are a by-product of that action. Sounds, in this new perspective, are only a ‘medium’ via which action of the triggering-person is mirrored onto the listener. This change in perspective has important consequences for devising therapies and treatment methods for misophonia. It suggests that instead of focusing on sounds, which many existing therapies do, effective therapies should target the brain representation of movement.”
Disclosure: One study author declared assistance from the Misophonia Research Fund and REAM Foundation, USA. Please see the original reference for a complete list of authors’ disclosures.
Reference
Kumar S, Dheerendra P, Erfanian M, et al. The motor basis for misophonia. J Neurosci. 30 June 2021, 41 (26) 5762-5770. doi:10.1523/JNEUROSCI.0261-21.2021
