The role of consciousness in threat extinction learning.
Charlene L M Lam, Tom J Barry, Jenny Yiend, Tatia M C Lee
Consciousness and cognition November 1, 2023 DOI: 10.1016/j.concog.2023.103599 via PubMed
Summary
Extinction learning, a process central to exposure therapy, may work differently when a feared stimulus is perceived without conscious awareness. In a threat conditioning experiment, healthy participants' pupils dilated more during extinction trials when they were unaware of the conditioned stimulus than when they were aware of it, with a moderate effect size. After fear was reinstated, recovery of fear was greater for the stimulus that had been suppressed from awareness during extinction. The findings suggest that extinction with reduced visual awareness weakens the modulation of fear responses compared to extinction with full perceptual awareness.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Healthy participants |
| Keywords | Continuous flash suppression Fear Implicit extinction Pupil Threat conditioning |
| Citations | 1 |
| Key finding | Extinction with reduced visual awareness produces weaker modulation of fear responses than extinction with full perceptual awareness, as indicated by greater fear recovery after reinstatement for the suppressed stimulus. |
Abstract
Extinction learning is regarded as a core mechanism underlying exposure therapy. The extent to which learned threats can be extinguished without conscious awareness is a controversial and on-going debate. We investigated whether implicit vs. explicit exposure to a threatened stimulus can modulate defence responses measured using pupillometry. Healthy participants underwent a threat conditioning paradigm in which one of the conditioned stimuli (CS) was perceptually suppressed using continuous flash suppression (CFS). Participants' pupillary responses, CS pleasantness ratings, and trial-by-trial awareness of the CS were recorded. During Extinction, participants' pupils dilated more in the trials in which they were unaware of the CS than in those in which they were aware of it (Cohen's d = 0.57). After reinstatement, the percentage of fear recovery was greater for the CFS-suppressed CS than the CS with full awareness. The current study suggests that the modulation of fear responses by extinction with reduced visual awareness is weaker compared to extinction with full perceptual awareness.