Stressor controllability modulates fear extinction in humans

Abstract

Traumatic events are proposed to play a role in the development of anxiety disorders, however not all individuals exposed to extreme stress experience a pathological increase in fear. Recent studies in animal models suggest that the degree to which one is able to control an aversive experience is a critical factor determining its behavioral consequences. In this study, we examined whether stressor controllability modulates subsequent conditioned fear expression in humans. Participants were randomly assigned to an escapable stressor condition, a yoked inescapable stressor condition, or a control condition involving no stress exposure. One week later, all participants underwent fear conditioning, fear extinction, and a test of extinction retrieval the following day. Participants exposed to inescapable stress showed impaired fear extinction learning and increased fear expression the following day. In contrast, escapable stress improved fear extinction and prevented the spontaneous recovery of fear. Consistent with the bidirectional controllability effects previously reported in animal models, these results suggest that one's degree of control over aversive experiences may be an important factor influencing the development of psychological resilience or vulnerability in humans.

Rethinking Extinction

“…Using a triadic design that included ES, IS and no shock groups, Baratta et al (2007) found that a session of ES in a different context 24 hours after fear conditioning facilitated subsequent extinction learning relative to IS and control groups, and eliminated spontaneous recovery. A similar study in humans found that an ES session a week prior to fear conditioning, extinction and a spontaneous recovery test also enhanced extinction relative to IS and control groups, and eliminated spontaneous recovery (Hartley et al, 2014). Stressor controllability effects have been shown to depend on plasticity within the vmPFC, which facilitates inhibitory control over brainstem nuclei and the amygdala (Maier and Watkins, 2010).…”

“…Although on the surface it may seem that active avoidance and escape from fear paradigms could result in protection from extinction in which a new behavior that eliminates the CS or US prevents extinction learning (see Psychological and Cognitive Factors for a description), recent research on stressor controllability suggests a key difference between the augmentation of extinction with active avoidance and the impairment of extinction observed in protection from extinction paradigms is the subjective perception of internal control in eliminating the presentation of the CS or US (Hartley et al, 2014). In active avoidance and stressor controllability the source of eliminating the aversive event is attributed to the learned actions of the animal, whereas in protection from extinction the source is attributed to external circumstances.…”

Motivation and cognitive control in depression

“…However, developments in the field of learned helplessness suggest that the interactions between stress and controllability are crucial for stress regulation . Recent research is starting to provide paradigms to study stress controllability in humans (Bhanji et al, 2016;Hartley et al, 2014).…”

Stress and Fear Extinction

“…For example, stress exposure (e.g., cold pressor) impairs the extinction (Hartley et al, 2014) of a conditioned galvanic skin response. Moreover, stress exposure prior to retrieval testing impairs the expression of extinction, resulting in a return of conditional responding (Merz et al, 2014;Raio et al, 2014).…”