NCT05168592

The Neural Mechanisms of Imaginal Extinction

Exploring the Neural Mechanisms of Imaginal Extinction Using fMRI and Psychophysiology

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 87 (actual)
• Sponsor: Uppsala University · Academic / Other
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

Imaginal exposure is a widely used and effective psychological treatment technique in which patients are exposed to fearful stimuli and situations using mental imagery. This study examines imaginal extinction, an experimental analogue of imaginal exposure that allows the study of this treatment technique under controlled circumstances. During imaginal extinction, conditioned fear is diminished through repeated exposure to mental imagery of the feared (conditioned) stimulus. The neural underpinnings of imaginal extinction is not known, and hence, this study examines neural activations during imaginal extinction using psychophysiology and brain imaging.

Detailed description

In this study, participants undergo threat conditioning to two pictures (CS+, CS-) in order to acquire a conditioned threat response. After this, the conditioned threat response is diminished through imaginal extinction (i.e extinction to the mental imagery of CS+ and CS-). Functional magnetic resonance imaging (7T) is used to measure neural activations during threat conditioning and imaginal extinction. Skin conductance is used to measure arousal response. Subjective fear and mental imagery vividness ratings will also be collected. In this way, this study aims to characterize the neural underpinnings of imaginal extinction. Note that this study employs participants fearful of spiders. This is because data collection is shared with a related study (ClinicalTrials.gov ID 2020-06930a).

Conditions

• Fear of Spiders

Interventions

Type	Name	Description
BEHAVIORAL	Threat conditioning	Day 1: The participant is repeatedly shown two stimulus (CS+,CS-), one at a time. CS+ is paired with an electric shock. CS- acts as a control stimulus. The stimuli consist of photos of two different objects. Stimuli will be counterbalanced between participants.
BEHAVIORAL	Imaginal extinction	Day 1: Participants are repeatedly instructed to produce mental imagery of the two stimuli used during threat conditioning. Imagery is prompted through different written instructions presented in pseudo-randomized order on a screen. No shocks will be delivered.

Timeline

• Start date: 2022-04-07
• Primary completion: 2023-03-01
• Completion: 2023-03-01
• First posted: 2021-12-23
• Last updated: 2024-08-26

Locations

1 site across 1 country: Sweden