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Completed

NCT Number: NCT05168592

The Neural Mechanisms of Imaginal Extinction

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.

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Key information

Conditions

Fear of Spiders Arachnophobia

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

The Swedish 7T facility

Lund, 22242, Sweden

About this study

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).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Willing and able to provide informed consent and complete study procedures
  • Fear of spiders (due to data collection together with ID 2020-06930a)

Exclusion criteria

  • Current psychiatric disorder other than spider phobia. Current use of psychotropic medication. Current neurological conditions. MRI-contraindications (i.e metal implants in skull).

Treatment and study plan

Threat conditioning

Behavioral

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.

Imaginal extinction

Behavioral

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.

Primary outcomes

  1. Blood oxygen level dependent contrast (BOLD-signal) during threat conditioning and imaginal extinction.

    Time frame: Day 1

    BOLD-signal is assessed using functional magnetic resonance imaging.

  2. Physiological arousal response during threat conditioning and imaginal extinction.

    Time frame: Day 1

    Skin conductance responses are used as a measure of physiological arousal response (i.e. event-related rise in electrodermal activity to stimuli).

Secondary outcomes

  1. Task-specific mental imagery vividness during imaginal extinction

    Time frame: Day 1

    Vividness of Imagery (scale:1-5; no image at all - image as clear and vivid as real life)

  2. Ratings of subjective fear experienced during threat conditioning and imaginal extinction.

    Time frame: Day 1

    Scale 0-100; no fear at all - extreme fear

  3. Spielberger State-Trait Anxiety Inventory (STAI-T)

    Time frame: One week after Day 1

    STAI-T is a self-rated questionnaire included assess trait-anxiety in the participants. Scale: 20-80, where higher scores represent higher levels of trait anxiety.

  4. Vividness of visual imagery Questionnaire (VVIQ)

    Time frame: One week after Day 1

    VVIQ is used to measure individual differences in the Vividness of Visual mental Imagery; scale: 16-80 where higher scores represent a higher ability for visual imagery.

Sponsors and collaborators

Lead sponsor

Uppsala University

Other

Registry information

Official study title

Exploring the Neural Mechanisms of Imaginal Extinction Using fMRI and Psychophysiology

Important dates

Study start
2022
Primary completion
2023
Study completion
2023
First posted
Dec 23, 2021
Registry last updated
Aug 26, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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