Latent cause inference during extinction learning in trauma-exposed individuals with and without PTSD

Abstract

Background Problems in learning that sights, sounds, or situations that were once associated with danger have become safe (extinction learning) may explain why some individuals suffer prolonged psychological distress following traumatic experiences. Although simple learning models have been unable to provide a convincing account of why this learning fails, it has recently been proposed that this may be explained by individual differences in beliefs about the causal structure of the environment. Methods Here, we tested two competing hypotheses as to how differences in causal inference might be related to trauma-related psychopathology, using extinction learning data collected from clinically well-characterised individuals with varying degrees of post-traumatic stress (N = 56). Model parameters describing individual differences in causal inference were related to multiple post-traumatic stress disorder (PTSD) and depression symptom dimensions via network analysis. Results Individuals with more severe PTSD were more likely to assign observations from conditioning and extinction stages to a single underlying cause. Specifically, greater re-experiencing symptom severity was associated with a lower likelihood of inferring that multiple causes were active in the environment. Conclusions We interpret these results as providing evidence of a primary deficit in discriminative learning in participants with more severe PTSD. Specifically, a tendency to attribute a greater diversity of stimulus configurations to the same underlying cause resulted in greater uncertainty about stimulus-outcome associations, impeding learning both that certain stimuli were safe, and that certain stimuli were no longer dangerous. In the future, better understanding of the role of causal inference in trauma-related psychopathology may help refine cognitive therapies for these disorders.

Trait anxiety is associated with hidden state inference during aversive reversal learning

“…The results corroborate previous theoretical predictions. In particular, parcellation into separate states (or "contexts") was proposed to be associated with anxiety disorders and account for relapse phenomena (Bouton, 2002;Gershman & Hartley, 2015, see also Norbury et al, 2021).…”

“…While much research supports the general existence of a state inference mechanism, the question of which factors influence the creation of internal states, and how trait anxiety might relate to it, has remained less clear. First, the role of trait anxiety (TA) in state inference has not been explicitly tested, although some studies suggest such a link (Gershman & Hartley, 2015; see also Norbury et al, 2021 for the same proposition in PTSD). High TA has been associated with an increased return of fear following phobia treatment (Rodriguez et al, 1999) and in renewal experiments (Staples-Bradley et al, 2018) as well as with heightened neural and physiological differentiation between cues associated with a shock (CS+) vs no shock (CS-) (Indovina et al, 2011;Sehlmeyer et al, 2011;Sjouwerman et al, 2020).…”

Anxiety as a disorder of uncertainty: Implications for understanding maladaptive anxiety, anxious avoidance, and exposure therapy

“…In tasks or blocks with high unexpected uncertainty (20 or fewer trials per block; Brown et al, 2018;Zika et al, 2022 andvolatile blocks in Browning et al, 2015;Gagne et al, 2020), people with anxiety show slightly slower learning overall, but accelerate learning more after very surprising outcomes that indicate obvious changes. Meanwhile, in tasks or conditions with high irreducible uncertainty (75%/25% contingency or less), people with anxiety show a generally higher learning rate, particularly after surprising losses (Homan et al, 2019;Huang et al, 2017;stable blocks in Browning et al, 2015;Gagne et al, 2020) -though this effect is less consistent (Norbury et al, 2021;Zika et al, 2022). These patterns suggest that people with anxiety have an impaired ability to discern whether prediction errors result from irreducible uncertainty, requiring a slower learning rate, or true changes in contingencies, requiring a higher learning rate.…”

“…Second, studies with reward and loss learning conditions have generally found differences during loss learning only (Brown et al, 2018;Browning et al, 2015), though some have found differences in both conditions (Gagne et al, 2020). Lastly, a few studies show diagnostic specificity to fear-versus distress-based disorders and symptoms (Brown et al, 2018;Norbury et al, 2021). In contrast, studies comparing GAD and MDD have not found specificity to symptoms of one of these disorders (Gagne et al, 2020).…”

Anxiety as a disorder of uncertainty: implications for understanding maladaptive anxiety, anxious avoidance, and exposure therapy

“…Internalizing disorders comprise depression, anxiety, and related disorders (including PTSD and OCD) and can be further divided into fear-versus distress-based disorders and symptoms (Craske et al, 2009;Watson, 2005). Specifically, some studies have found learning differences that were related to fear, and not distressbased, disorders and symptoms (Brown et al, 2018;Norbury et al, 2021). In contrast, a study comparing GAD and MDD did not find specificity to symptoms of one of these disorders (Gagne et al, 2020).…”