Predictive Processing and the Varieties of Psychological Trauma

Abstract

A recently popular framework in the cognitive sciences takes the human nervous system to be a hierarchically arranged Bayesian prediction machine. In this paper, we examine psychological trauma through the lens of this framework. We suggest that this can help us to understand the nature of trauma, and the different effects that different kinds of trauma can have. We end by exploring synergies between our approach and current theories of PTSD, and gesture toward future directions.

Trauma or Drama: A Predictive Processing Perspective on the Continuum of Stress

“…PPF has recently been applied to trauma (Wilkinson, Dodgson, & Meares 2017, Linson & Friston 2019, where different manifestations of PTSD are regarded as a trauma-induced malfunction of the brain's generative model. For example, dissociation is thought to result from the fragmentation of the generative model, where the model of the self is disconnected from the model of the traumatic event.…”

“…For example, dissociation is thought to result from the fragmentation of the generative model, where the model of the self is disconnected from the model of the traumatic event. Consequently, the self-model fails to be updated by the ascending interoceptive prediction errors, making the trauma felt as happening not to oneself (Wilkinson, Dodgson, & Meares 2017). As a result, the negative affect is mitigated during a traumatic event, which may be adaptive as a peri-traumatic response but becomes maladaptive long-term, making dissociation one of PTSD symptoms (DSM-5).…”

“…Then, the remaining option is an abrupt overhaul of the model's network of priors, often leading to dysregulation within the model, e.g. dissociation or psychosis (Wilkinson, Dodgson, & Meares 2017). Such dysregulation corresponds to "breakdown of self-regulatory functions" suggested as the sufficient condition and a defining feature of TSR (Krupnik 2019).…”

“…If so, such inference is expected to return to its normative range once the threat is over. However, if the mind is under control of hyper-precise exteroceptive 'threat' priors, the threat never ceases (Wilkinson, Dodgson, & Meares 2017). Consequently, to minimize uncertainty, interoceptive inference needs to match the exteroceptive one by, too, becoming hyper-precise in predicting an emergency stress response (Fig 2b).…”

“…Whereas the described model of TSR (Fig 1, 2) is speculative and has not been directly tested, much of empirical knowledge about trauma appears consistent with it. The evidence that trauma and PTSD, in particular, are associated with false inference, where hyper-precise threat priors skew the perception (sometimes to the point of flashback and hallucination) has been reviewed before (Wilkinson, Dodgson, & Meares 2017). Likewise, false interoceptive inference in PTSD has been extensively discussed (Linson & Friston 2019).…”