However, in modern times it has become increasingly difficult to categorize disorders in this way because disorders overlap, and causality is often unknown. This, of course, adds to the confusion.
Neuroscientist Joseph E. LeDoux has been studying the implications of auditory over-responsivity in the part of the brain called the amygdala. The amygdala plays an important role in the body’s fight/flight/freeze processes. It is because of the nature of the amygdala and the limbic system that misophonia is most-likely neurological in origin.
The amygdala is also involved with memory. In terms of misophonia, regardless of whether or not one is born with the disorder individuals make memories in which the body’s fight/flight response is associated with particular sounds. In addition, some of us may be born with a higher arousal system, or may simply be more sensitive to auditory stimuli. Therefore, some of us may be more vulnerable to forming these memories. The perception of memory offers reasonable theories as to why cognitive therapies such as CBT have shown little progress for misophonia, and have been said to make the disorder worse. Dr. LeDoux is working on whether or not memory reconsolidation therapy can have an impact on persons with misophonia. This research is particularly interesting because it is widely innovative in regard to approaches for misophonia.
Edelstein, Brang, Rouw, and Ramachandran (2013) found some similarities between Synesthesia and Misophonia. Edelstein et al. proposed that misophonia “displays similarities” to synesthesia. Edelstein et al. used both self-report (qualitative interviews) and physiologic measures (Skin Conductance Response, or SCR) to characterize aversive reactivity in Misophonia:
“The underlying neurological cause of this condition may be similar to that of synesthesia in terms of enhanced connectivity between relevant brain regions. In short, a pathological distortion of connections between the auditory cortex and limbic structures could cause a form of sound-emotion synesthesia.” (Edelstein et al., 2013).
The authors note that limitations of the study include small sample size, a lack of screening for psychiatric or psychological problems (no measures of mental health disorders were included), and that SCR measures autonomic arousal, but does not describe the nature of the emotion associated with that autonomic arousal.
As you may have noted, the synesthesia research is applicable to Misophonia as it directly addresses the aberrant brain connectivity that the Jastreboff’s originally conceived of.
While synesthesia research does not directly translate into treatment, it can certainly further our understanding of the disorder and therefore inform treatment. There are a few more synesthesia research studies underway and it will be interesting to find out results.