Active inference, stressors, and psychological trauma: A neuroethological model of (mal)adaptive explore-exploit dynamics in ecological context

Abstract

This paper offers a formal account of emotional inference and stress-related behaviour, using the notion of active inference. We formulate responses to stressful scenarios in terms of Bayesian belief-updating and subsequent policy selection; namely, planning as (active) inference. Using a minimal model of how creatures or subjects account for their sensations (and subsequent action), we deconstruct the sequences of belief updating and behaviour that underwrite stress-related responses -and simulate the aberrant responses of the sort seen in posttraumatic stress disorder (PTSD). Crucially, the model used for belief-updating generates predictions in multiple (exteroceptive, proprioceptive and interoceptive) modalities, to provide an integrated account of evidence accumulation and multimodal integration that has consequences for both motor and autonomic responses. The ensuing phenomenology speaks to many constructs in the ecological and clinical literature on stress, which we unpack with reference to simulated inference processes and accompanying neuronal responses. A key insight afforded by this formal approach rests on the trade-off between the epistemic affordance of certain cues (that resolve uncertainty about states of affairs in the environment) and the consequences of epistemic foraging (that may be in conflict with the instrumental or pragmatic value of 'fleeing' or 'freezing'). Starting from first principles, we show how this trade-off is nuanced by prior (subpersonal) beliefs about the outcomes of behaviour -beliefs that, when held with unduly high precision, can lead to (Bayes optimal) responses that closely resemble PTSD.

Deeply Felt Affect: The Emergence of Valence in Deep Active Inference

“…In future work, we will move beyond AC and characterize the richness of core affective states in the (hyper)parameters of a generative model that applies to a wide range of lower-level generative models (i.e., of many different shapes and settings). Another important direction will be to connect our model to other active inference models used to simulate approach/avoidance behavior and emotion-cognition (Linson, Parr, & Friston, 2020 ; Smith, Parr, & Friston, 2019 ; Smith, Lane, Parr, & Friston, 2019 ; Smith, Kirlic et al, in press).…”

Losing Ourselves: Active Inference, Depersonalization, and Meditation

“…In other words, how would such a system behave if unexpected error continued to rise regardless of perceptual updates and behavioral interventions? For example, in active inference terms, trauma could be understood as a massive influx of prediction error causing the system to drastically lower confidence (precision) in its action models (see Linson et al, 2020 ). In the case of physical trauma, the body’s integrity, which is highly expected, is seriously disrupted or damaged.…”

Imprecise action selection in substance use disorder: Evidence for active learning impairments when solving the explore-exploit dilemma

“…While these studies exemplify progress in identifying potentially meaningful differences, understanding of several aspects of aberrant decision-making in SUDs remains incomplete. One area in which further investigation may be useful is how individuals with SUDs solve what is known as the explore/exploit dilemma, which has recently been highlighted as of potential importance in psychiatric disorders (Addicott et al, 2017;Linson et al, 2020). This dilemma arises in cases where decisions must first be taken to gather information about the environment, before exploiting knowledge of the environment to maximize reward.…”