The History of Misophonia Research, by Jennifer Jo-Brout, Psy.D (Part III of III)

In part I and II we talked about the confusion in terminology and positioning regarding misophonia:

Does it belong to audiology or psychology or neuroscience… and so on.

One thing is very clear.

There is a remarkable overlap in Misophonia symptoms and Sensory Over-Responsivity (SOR), a subtype of Sensory Processing Disorder (SPD).

The Overlap of Sensory Processing Disorder and Misophonia

Work in SPD began in the field of Occupational Therapy but has expanded to include neuroscience, psychology, psychiatry, and genetics over the past 15 years.

This impressive body of research supports that particular groups of young children misperceive auditory, visual, tactile and other stimuli as highly aversive and dangerous.

Notably, the research in SOR has been related mainly to children, although currently it addressing adults.

While SOR research concerns a variety of sensory stimuli, it is important to note that within these groups were children known as mainly “auditory over-responsive.”

There are numerous papers that separate out auditory over-responsive symptoms, as well as studies focused specifically on auditory gating*

SPD/SOR research, even that which was specific to the auditory modality, did not differentiate between loud and repetitive sounds. This makes it difficult to extrapolate from SOR to Misophonia.

However, the overlap in behavioral symptoms in regard to “auditory over-responsivity” is remarkable. [1] 

Brief History of SOR research

As far back as 1999 studies of children considered SOR demonstrated autonomic arousal and decreased habituation.

Specifically, measured by galvanic skin response (GVS), children who were presented with every day sensory stimuli were propelled into the fight/flight response.

Once, fight/flight was activated they did not habituate**

Notably, these and other studies of SOR children have been replicated over the past 15 years, and have included numerous other physiologic and brain imaging studies showing differences between typicals and SOR children, as well differences between typical children and children with more general atypical sensory processing problems.***

Because SPD is not yet validated by psychiatry, this impressive body of literature is often overlooked in psychiatric and psychology research.

This is despite the past decade of SPD scholarship, which includes contributions from esteemed researchers within psychiatry, psychology, and basic science.****

SPD and its proposed phenotypes are conceptually complicated and regardless of it’s omission from the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition), the body of research informs misophonia research and should not be dismissed by those investigating this condition.

Nature versus Nurture?

When conceptualizing Misophonia it is important to note that the distinction nature versus nurture (which is inexorably entwined with the “conditioned versus constitutional paradigm”) is a dated model in genetics.

The interaction of genes and the environment is known to be more amorphous and less distinguishable than previously thought.

Gene regulation (in which genes can be turned on or off according to environmental factors) has shifted focus off this debate and onto ways of optimizing brain plasticity in various modalities of therapeutic treatment.

A pattern of disregard of this shift has already filtered through the small body of Misophonia literature, and it is important to pursue further research within this current gene regulation (or nature via nurture paradigm).

I am not a geneticist. Yet, one does not need to be a geneticist to know this. This is common knowledge in the allied health professions, and the even in popular press.

People Noises versus Repetitive Noises

An important issue arising out of this relatively rigid use of the nature versus nurture idea relates to conflation between types of sounds that may cause the emotional and behavioral response noted in misophonia with the people from whom these sounds emanate.

As the Jastreboff’s (2001) originally suggested, misophonia sufferers aversively react to pattern-based sounds.

While many of these sounds are person-oriented (e.g. chewing, coughing, sneezing, etc.) many are not (e.g. pencil tapping, basketball bouncing, typing on a keyboard, etc.).

The Jastreboff’s hypothesized that negative cognitive association between these particular types of sounds and the misophonia sufferer had occurred, and could possibly be retrained.

Yet, they did not suggest that only “people” or “body noises” were the cause of the aversive reactivity, nor did they describe people specifically as triggers. The Jastreboff’s suggested that in Misophonia, the individual associated pattern-based sounds with people/and or experiences, etc.

They did not suggest that “people” themselves were the cause of the aversive reactivity. They suggested an association between a person and a sound, as well as aversive reactivity to pattern-based sounds alone.

This confusion is highly misleading. At the same time, it may demonstrate the sufferers’ own difficulty differentiating the sound and the person(s) associated with the sounds.

Similarly, this confusion may reflect the difficulty researchers and misophonic individuals may have parsing out the interactive physiological, cognitive, and emotional, processes that combine with relational dynamics to explain human behaviour.

Summary of Important Points

  • Misophonia research is in its infancy. There are less than 20 studies that directly concern misophonia.
  • Within most of this research, important related bodies of research have been omitted.
  • These bodies of research need to be considered in order to formulate hypothesis about the nature of misophonia prior to conclusions regarding further studies, and certainly about treatment.
  • At the same time, it is important to note that these other bodies of research strongly support misophonia as a valid syndrome or disorder and research is needed ASAP.
  • There is no evidence that supports that misophonia is a genetic versus conditioned disorder, nor is this model necessarily applicable at this time.
  • There is no evidence that body/people noises versus patterned based noises are differentiated. The complicated and interactive processes related to overall arousal level, relational dynamics, and memory will make this difficult to parse out in the research.
  • In the meantime, sufferers, researchers and press should be aware of this complication and not make assumptions.
  • As science is a work in progress, this article will be updated accordingly. It may be obsolete by next week. Let’s hope so!

Sources:

[1] Auditory over-responsivity refers to SOR, but in regard to the auditory sense alone
* e.g. Gavin, W. J., Dotseth, A., Roush, K. K., Smith, C. A., Spain, H. D., & Davies, P. L., 2011.
** e.g. McIntosh, Miller, Shyu, & Hagerman, 1999; James, Miller, Schaff, Neilsen, & Schoen, 2011
*** e.g. Davies & Gavin, 2007; Davies et al., 2009, 2010; Davies, Chang, & Gavin, 2009; Gavin et al., 2011; Van Hulle, Schmidt, & Goldsmith, 2012; Owen et al., 2013; Schneider et al., 2009
**** e.g. Goldsmith et al., 2006, Kisley M.A., Noecker L., Guinther  2006, Rosenthal, Ahn & Gieger, 2011

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