Hypermirroring vs JDH & Related Thoughts

To my mind there are two viable candidates for a model of misophonia: one in which (hyper-) mirroring of orofacial actions is the main driver, and one in which conscious or subconscious awareness of jaw dysfunction and consequent airway restriction (within the sufferer) is the main driver.

Each has potential contradictions to contend with. For the jaw dysfunction hypothesis (JDH), they are:

• Not everyone with jaw dysfunction (which is almost everyone) has misophonia. There must be another factor(s) at play.

• If jaw dysfunction is the main driver, why does hypermirroring need to be involved at all? Maybe hypermirroring is this other necessary factor.

For hypermirroring, the following must be explained:

• If hypermirroring is the main driver, how can people self-trigger? Is there such a thing as self-mirroring? This seems like an oxymoron—mirroring by definition involves perception of another person—but maybe that other person can be imagined. Our own orofacial actions could feed into an image of “a person” doing those actions, which could feed back into the mirroring system.

It occurs to me that I don’t even know that what I call self-triggered misokinesia—finding the sensation of my jaw configuration enraging—and misophonia are even the same thing. I’ve put them under the same umbrella because they have a similar feel: extreme rage caused by an otherwise trivial stimulus, combined with a sense of violation. It seems reasonable to proceed on the assumption that these are related, especially since there are so many other connections and ways that they play off each other—think of how many misophonia trigger sounds are also indicators of jaw dysfunction—but, as I’ve said elsewhere, it’s important to keep an open mind to the possibility that these are only superficially related.

One thing that provides an easy answer for both candidate models in response to the above questions is the idea of associative learning. This refers to the brain’s ability to connect two things that happen in short succession and to learn to predict the sequence, creating an image of the second thing in response to the first. So for the hypermirroring model to account for the apparent existence of self-triggers, maybe all that’s required is that the sufferer makes a conceptual connection between eating sounds and misophonic distress, and for that association to eventually become strong enough for the sufferer’s own eating to become at least a psuedo-trigger. Associative learning, by its arbitrarily flexible nature, allows for almost any observation to be explained away within a given model.

In my own case, one possible explanation for my self-triggered misokinesia could be my changing jaw structure causing patterns of firing in orofacial motor areas that have previously been associated with hypermirroring-based triggers. This is a B -> A scenario. It could involve mirroring mechanisms or not; either way it would be an example of my brain learning that certain orofacial sensations are associated with rage and then producing rage when those sensations occur.

Associative learning also confounds the search for a core mechanism of misophonia, because it allows for the possibility of feedback loops and obscures the direction of causality. If the fundamental process is that A causes B, but the brain learns to associate B with A to the point of creating A when it encounters B, it becomes impossible to say anything certain about the original causal relationship, which could otherwise be used as the foundation or an intermediate step within a model. It could be that A is hypermirroring and B is an increased awareness of one’s own actual jaw dysfunction. Conceivably, even without associative learning, either one of these could cause the other. With associative learning, it’s even harder to say which, if any, might be the ultimate driver.

Response to the JDH

I’ve put forward the JDH on the misophonia subreddit a few times, to limited response. No-one has outright contradicted it and a few people have expressed interest or noted that they also have e.g. TMJ issues, but it hasn’t been the revelation that I expected.

Whether the JDH is true or not, I think this may be because jaw dysfunction is so latent. The teeth are such a fundamental reference point within the body, and so important for every aspect of its working, that we are almost forced to compensate for underdevelopment with e.g. forward head posture and assume in a deep way that our teeth are where they’re supposed to be. The front of the teeth feels like the front of the face, even though there is actually nothing where the front of the face should be and the teeth are retruding back into what should be the empty space of the mouth.

I certainly wouldn’t have believed that my teeth needed to move forward if you’d told me even in March 2023. It requires a lot of mental effort to imagine a different configuration and to realise that it would be an improvement.

Current Bet

On balance, I’ve recently started thinking that mirroring may be a more solid foundation for a model of misophonia/misokinesia. It’s hard to articulate why exactly, but some of it is that almost all of my jaw dysfunction-related triggers seem to also have a mirroring aspect, where the negative affect seems to be driven by a sense of being violated by another person, whereas not all aspects of jaw dysfunction seem to be triggers, as one would expect in a jaw dysfunction-driven model. Moreover, sensations of choking or constriction that are related to actual airway obstruction do not seem to be triggers, as one might reasonably expect in a model driven by that sensation. So as I’ve said elsewhere, I think there are potentially at least two necessary factors—mirroring and some kind of negative quality to the mirrored action—but if I had to bet on one of them being primarily responsible for the particular feeling of violation characteristic of misophonia, I think it would have to be the mirroring. Why some actions are mirrored more strongly than others, and how exactly the misophonic response is ultimately generated, is still an open question in this model—as are points I’ve mentioned above such as the question of self-triggering.

Another reason is related to the construction theory of emotion. Before, I’ve argued that there must be some reason why we produce negative affect in response to trigger stimuli, and that mirroring alone is not enough. The idea was that we construct feelings of violation or transgression after feeling negative affect associated with trigger stimuli, with the negative affect being driven by feelings of actual dysfunction or constriction. I now agree with the position in the mirroring paper that hypermirroring alone should be sufficient to generate negative affect, because having someone else intrude into your personal space and control your actions—whether in an abstract or more direct way—should be sufficient to cause negative affect. Whether the ultimate subjective experience draws from experiences of actual constriction by way of analogy or some other mechanism, I don’t know—but it seems fairly clear to me now that in any case, nothing else is necessary for perceptions of violation—however abstract—to be fundamental drivers of negative affect.