NCT05193383

Neural Mechanisms of Imaginal and in Vivo Exposure

Neural Mechanisms of Imaginal and in Vivo Exposure: Exploring the Differences Between Imaginal and in Vivo Exposure, 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. Recent research suggests that neural activations and emotional responses during imaginal exposure are similar to those elicited during in vivo exposure. However, to the investigators knowledge, no direct comparison between in vivo and imaginal exposure has been performed during neuroimaging. This study compares neural activations and emotional responses during imaginal and in vivo exposure. This study also explores the generalizability of fear reduction achieved through imaginal exposure to fear responses elicited by in vivo stimuli, and vice versa, in a follow-up session approximately one week later. A better understanding of the mechanisms behind both types of exposure could have significant clinical utility, as well as elucidate the differences between fear created from outward stimuli and fear created from inward stimuli, such as mental imagery.

Detailed description

The study includes participants fearful of spiders and entails two experimental sessions, roughly one week apart. The first session includes brain imaging using functional magnetic resonance imaging (fMRI). During the first session, participants will be randomized into one of two conditions - in vivo exposure or imaginal exposure. In the in vivo exposure condition, participants will be shown video clips of spiders (fearful stimuli) and leaves (neutral stimuli) in different situations. In the imaginal exposure condition, participants will be instructed to produce mental imagery of the corresponding stimuli used for in vivo exposure. Previous research found that the brief exposure procedure used during session 1 produced a fear reduction when the procedure was repeated one week later. Thus, in order to conceptually replicate this finding, and to examine the generalizability of fear reduction, participants return roughly one week later for a follow-up session. In the follow-up session, participants undergo a similar exposure procedure as used in session 1, but with half of the stimuli in vivo and the other half of the stimuli as mental imagery. In this way, it can be studied whether fear reduction generalize from exposure modality to another. The effects of imaginal and in vivo exposure on avoidance behavior towards fear-provoking stimuli (spiders) will also be assessed using an approach-avoidance conflict paradigm, using pictures of spiders to probe spider fear. The current study will also explore the impact of mental imagery vividness during imaginal exposure on fear reduction. Additionally, the study will assess if vividness level can predict the generalizability of the effects of imaginal exposure to fear-provoking stimuli (mental imagery of a spider) on subsequent fear responses to to in vivo stimuli (film clip of a spider) one week later. Functional magnetic resonance imaging (7T) is used to measure neural activations (session 1). Skin conductance is used to measure arousal response (session 1 \& 2). Subjective fear and mental imagery vividness ratings will also be collected.

Conditions

• Fear of Spiders

Interventions

Type	Name	Description
BEHAVIORAL	Imaginal exposure	Session 1 (Day 1): Participants receive repeated exposure to mental imagery of fear-provoking stimuli (spiders) and neutral stimuli (leaves) while undergoing brain imaging med fMRI.
BEHAVIORAL	Exposure	Session 2 (Ca one week): Participants receive both imaginal and in vivo exposure to fear-provoking stimuli and neutral stimuli (both arms are exposed to both video clips (in vivo exposure) and mental imagery (imaginal exposure). Session 2 is conducted in the laboratory, i.e., no brain imaging.
BEHAVIORAL	Approach-avoidance conflict	Session 2 (Ca one week): Spider fear is probed by an approach-avoidance conflict task. Participants can receive varying small rewards for watching pictures of spiders, or avoid the spider pictures at the cost of not receiving a reward (neutral pictures are shown instead).
BEHAVIORAL	In vivo exposure	Session 1 (Day 1): in vivo exposure. Participants receive repeated exposure to film clips of fear-provoking stimuli (spiders) and neutral stimuli (leaves) while undergoing brain imaging med fMRI.

Timeline

• Start date: 2022-04-07
• Primary completion: 2023-03-01
• Completion: 2023-03-01
• First posted: 2022-01-14
• Last updated: 2024-08-26

Locations

1 site across 1 country: Sweden