Dr. Sukhbinder Kumar, and his team from the Institute of Neuroscience at Newcastle University and the Wellcome Centre for NeuroImaging at University College London (UCL) published a groundbreaking misophonia study, which recently appeared in Current Biology.
What makes this study “ground-breaking?”
In an interview with Dr. Kumar, he explains the study and what it might mean for people with misophonia.Dr. Kumar states that his team’s findings provide “strong evidence that misophonia is a “real disorder. Specifically, using Magnetic resonance imaging (MRI) Kumar’s team found identifiable differences in the brains of misophonic individuals. The study reveals numerous important findings.
First, there is a notable difference in the connectivity in the frontal lobe between the cerebral hemispheres in people with misophonia. The difference appears to be due to higher myelination in the ventromedial prefrontal cortex (vmPFC). The vmPFC sits almost right above the eye-socket, the bottom middle towards the front of the brain. It is involved in processing and regulation of emotions like fear and empathy, and decision making.
“The higher myelination in this area of the brain in misophonia subjects suggests abnormal connectivity”
The myelin sheath cells are surround the connecting axons of neurons, allowing for, and increasing electrical conductivity between brain cells. Without this, cells could not communicate properly.
Also, the ventromedial prefrontal cortex is central to understanding misophonia because it is part of a complicated network of connections between numerous other areas of the brain. It both receives sensory information, processes that information and influences the functioning of many other brain areas including those involved in memory, olfaction and perhaps of great importance, the amygdala (where fight/flight is mediated and where salience, or importance, is assigned to incoming sensory stimuli).
The study also revealed that a major area involved in the brain’s ability to pick out what it thinks are “salient” ,or important, stimuli (the anterior insular cortex, or AIC) showed greater activation for misophonia subjects responding to trigger sounds. The AIC is involved in processing emotions and integrating sensory stimuli (such as sounds) from the both the outside world and from within the body.
Here, “salient” means picking out or paying attention to something that stands out from its neighbors, like off-color in the case of vision, or in this case, an off sound. Importantly, this area also showed abnormal “functional” connectivity to other brain regions highly involved in processing emotions, including the amygdala, the vmPFC, and the posteromedial cortex (PMC), also involved in emotional regulation.
Dr. Kumar hypothesizes that the difficulty in processing sensory information in these brain networks leads to a “mismatch between how a person perceives their physical state and what their physical state really is”. This refers to an often overlooked sense “interoception”, which allows us to accurately perceive our body states. As an example, Dr. Kumar explained, “that a person may feel as though they have a dry mouth. Yet objectively there mouth is not dry”. Dr. Kumar is very interested in this finding and is continuing research on how this relates to misophonia.