Scientists Have Found The Brain Circuit Behind Misophonia's 'Rage Response'

As many as one in five of us have misophonia, a severe reaction to everyday sounds such as chewing or sniffing. Despite it being relatively common, misophonia's origins in the brain are still something of a mystery.Past studies haven't been conclusive, but have pointed to the anterior insular cortex region of the brain, which plays roles in handling disgust and pain and in directing attention. This brain region is part of what's known as the salience network, which processes numerous internal and external cues.In a study published in Human Brain Mapping, researchers from the Montreal Neurological Institute in Canada and the University of Oklahoma in the US have now provided more evidence that the anterior insular cortex and the salience network are closely tied to misophonia.What's more, they suggest there's not a clear delineation between people with misophonia and people without."Our results provide neural evidence that misophonia exists on a spectrum, with observable differences in a large sample from the general population in which misophonia experiences vary," write the researchers in their published paper.

The team looked at functional magnetic resonance imaging (fMRI) scans of resting brains for 162 adults, available in an existing database.However, as this database didn't include specific information on misophonia, a separate analysis of 777 individuals who were asked about the disorder was used to estimate misophonia severity. Severity was based on general sensory responses (for example, how someone might react to a strong smell in a store).The researchers found that misophonia symptom severity was associated with how closely anterior insula activity was synced with areas of the salience network responsible for auditory processing, and motor and movement planning.The study found that brain activity linked to misophonia was distinct from other conditions. (Hansen et al., Hum. Brain Mapp., 2026)What's more, this clustering didn't meaningfully overlap with brain activity linked to anxiety, depression, or traits of autism.These conditions often accompany misophonia, and can make it difficult to tease out biological processes related specifically to misophonia."These results underline the importance of the salience-network anterior insula in understanding misophonic aversion and provide tentative evidence of neurological differences between misophonia and anxiety, depression, and autism," write the researchers.