Brain Imaging Research

Sukhbinder Kumar, Ph.D. explained his research on this topic in his presentation at the 2015 Misophonia Association Conference in Chicago and in the journal article, The Brain Basis for Misophonia.11 Dr. Kumar observed the brains on individuals exposed to trigger sounds with fMRI (functional magnetic resonance imaging). fMRI shows brain activity by measuring blood flow. Where more blood is flowing, there is more neuronal activity. The study compared 22 people with misophonia vs. 20 without misophonia. In response to trigger sounds, the people with misophonia had higher activity in the anterior insula, which is known to be involved in sensing inside the body and external senses (hearing, sight, taste, touch, and smell) and internal sensations (pain, stomach ache, muscle tension, etc.). Other research indicates that the anterior insula is involved in subjective feelings of emotions.No surprise here. We would all expect to see greater emotional brain activity for an individual with misophonia. The study also showed a connection between activity in the anterior insula and the vmPFC (ventromedial prefrontal cortex) and posteromedial cortex (PMC). These structures are key parts of is called the Default Mode Network which is involved in retrieval of memory. (For simplicity, I will only mention the vmPFC to indicate both the vmPFC and PMC.) This connectivity is very important because the vmPFC and is known to be involved in associative learning (or learning from experience). Essentially, this research shows that the brain response to trigger stimuli is a conditioned (learned) emotional response (an involuntary emotional reflex response). An individual with misophonia hears/sees a trigger and “boom” there is an instant, involuntary emotion forced on the person. With misophonia, the person does not choose how to feel after a trigger, it just happens automatically. For individuals without misophonia, the vmPFC acted to reduce activity in the anterior insula. Additionally, for individuals with misophonia, there was high activity between the anterior insula and the hippocampus and between the anterior insula and the amygdala. The following figure is from Dr. Kumar’s journal article. It illustrates the increased connectivity between these regions of the brain when person with misophonia is exposed to a trigger stimulus. It is used with permission from the journal article Kumar et al., The Brain Basis for Misophonia, Current Biology (2016), In the figure that follows,

The anterior insula is the center image
The vmPFC is the upper right image

The PMC is the upper left image

I exchanged email to clarify Dr. Kumar’s view of this and he provided the following quotes. “In misophonic subjects… the connectivity between vmPFC and anterior insula is positive, indicating that vmPFC, rather than regulating, is boosting the activity of anterior insula.” And, “Given the role of vmPFC in learning associations, our data is consistent with the view that aberrant associations represented in vmPFC drive areas involved in emotion processing.”

Here is my interpretation in plain English.

1. In individuals with misophonia, the vmPFC is supercharging the emotional response to the triggers, but in the controls the vmPFC is dampening the response.
2. Misophonia emotions are an acquired emotional reflex (a conditioned emotional response or CER)

3. The emotional response develops through experience with triggers.

4. The emotions are an involuntary reflex response.

5. The emotions from a trigger are not a choice of the person. Rather, they are activated or instantly inserted into the brain.