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Completed

NCT Number: NCT03989518

The Link Between Mental Imagery and the Reduction of Fear in Imaginal Extinction

Imaginal exposure is a widely used psychological treatment technique. Imaginal extinction is an experimental analogue of imaginal exposure, that allows the study of this treatment technique under controlled circumstances (Agren, Björkstrand, & Fredrikson, 2017). During imaginal extinction, experimentally induced fear is diminished through repeated exposure to mental imagery of the feared (conditioned) stimulus. However, it is not known to what extent fear reduction depends on the mental imagery produced during this procedure. A better understanding of the mechanisms driving the effects of imaginal exposure and the factors moderating fear reduction could have significant clinical utility, by suggesting mechanistically informed ways to improve this treatment.

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Key information

Conditions

Healthy Subjects

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Uppsala University, Departement of Psychology

Uppsala, Sweden

About this study

The study takes part over three consecutive days, with fear conditioning to visual stimuli on day 1, imaginal extinction on day 2, and a fear reinstatement procedure, again to visual stimuli, on day 3. Skin conductance is used to measure fear responses.

Participants' are randomized to receive conditioning, extinction and reinstatement with either complex or simple stimuli. During imaginal extinction, imagery of each experimental stimulus is prompted through different verbal instructions.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

Age 18 or over

Fluent in Swedish

Willing and able to provide informed consent and complete study procedures

Exclusion criteria

Current psychiatric disorder

Use of psychotropic medication within 6 months prior to study start

Receiving psychological treatment within 6 months prior to study start

Current neurological condition

Treatment and study plan

Fear acquisition

Behavioral

Day 1. Participants are exposed to two different visual stimuli. One of these stimuli is paired with a mild electric shock (i.e. conditioned stimuli).

Imaginal extinction

Behavioral

Day 2 (24 hours after Day 1). Participants are exposed to mental imagery of the stimuli used during fear conditioning. Imagery is prompted through different verbal instructions presented in a pseudo-randomized order. No shocks are delivered. Prior to imaginal extinction, participants receive task specific training.

Reinstatement

Behavioral

Day 3 (48 h after day1). Participants are exposed to the same stimuli used during fear conditioning (day 1) and imaginal extinction (day 2). Two unsignaled shocks are delivered at the beginning of the experiment, prior to the presentation of the first visual stimulus. No further shocks are delivered. This procedure allows the study of long term effects of imaginal extinction.

Primary outcomes

  1. Skin conductance response (SCR)

    Time frame: Day 1

    SCR is used as a measure of physiological fear responses. Differences in fear responses are used to assess fear learning during fear acquisition and to explore main effects and interactions between fear learning, stimulus complexity and capacity for mental imagery.

  2. Skin conductance response (SCR)

    Time frame: Day 2 (24 h after day1)

    SCR is used as a measure of physiological fear responses.Differences in fear responses are used to assess fear reduction during imaginal extinction, and to explore main effects and interactions between fear reduction, stimulus complexity and capacity for mental imagery.

  3. Skin conductance response (SCR)

    Time frame: Day 3 (48 h after day 1)

    SCR is used as a measure of physiological fear responses.Differences in fear response are used to assess return of fear during reinstatement, and to explore main effects and interactions between return of fear, stimulus complexity and capacity for mental imagery.

Secondary outcomes

  1. Fear ratings

    Time frame: Day 1

    Ratings of subjective fear during the experimental procedure. Scale: 0 -100 (no fear at all - extreme fear)

  2. State-Trait Anxiety Inventory

    Time frame: Day 1

    This is a self-rated questionnaire measuring trait anxiety. Higher scores indicate higher level of trait-anxiety (range 20-80)

  3. Difficulties in emotion regulation scale

    Time frame: Day 1

    This is a self-rated questionnaire measuring difficulties in emotion regulation. Higher scores indicate higher level of difficulties in emotion regulation (range 36-180)

  4. Fear ratings

    Time frame: Day 2 (24 h after day 1)

    Ratings of subjective fear during the experimental procedure. Scale: 0 -100 (no fear at all - extreme fear)

  5. Vividness of mental imagery during imaginal extinction

    Time frame: Day 2 (24 h after day 1)

    Scale: 1-5; no image at all - image as clear and vivid as real life

  6. The Plymouth Sensory Imagery Questionnaire

    Time frame: Day 2 (24 h after day 1)

    This is a self-rated questionnaire measuring vividness of mental imagery across different sensory modalities. Higher scores indicate higher level of vividness. (range 0-70)

  7. The Vividness of Visual Imagery Questionnaire

    Time frame: Day 2 (24 h after day 1)

    This is a self-rated questionnaire measuring vividness of visual mental imagery. Only eyes open section is administered. Higher scores indicate higher level of vividness (range 0-80)

  8. Spontaneous use of imagery scale

    Time frame: Day 2 (24 h after day 1)

    This is a self-rated questionnaire measuring spontaneous use of imagery. Higher scores higher levels use of spontaneous use of imagery (range 12- 60)

  9. Expectancy ratings

    Time frame: Day 2 (24 h after day 1)

    After the imaginal extinction procedure, participants are asked to rate to what extent they believed that electric shocks would be delivered during the procedure on a scale ranging from 0 - 100 %

  10. Fear ratings

    Time frame: Day 3 (48 h after day 1)

    Ratings of subjective fear during the experimental procedure. Scale: 0 -100 (no fear at all - extreme fear)

  11. Expectancy ratings

    Time frame: Day 3 (48 h after day 1)

    After the reinstatement procedure, participants are asked to rate to what extent they believed that electric shocks would be delivered during the procedure on a scale ranging from 0 - 100 %

Other outcomes

  1. Task compliance

    Time frame: Day 1

    Questions asking participants to rate to what extent they followed the instructions during the experimental procedure on a scale ranging from 0 - 100 %.

  2. Task compliance

    Time frame: Day 2 (24 h after day 1)

    Questions asking participants to rate to what extent they followed the instructions during the experimental procedure on a scale ranging from 0 - 100 %.

  3. Task compliance

    Time frame: Day 3 (48 h after day 1)

    Questions asking participants to rate to what extent they followed the instructions during the experimental procedure on a scale ranging from 0 - 100 %.

Sponsors and collaborators

Lead sponsor

Uppsala University

Other

Registry information

Important dates

Study start
2019
Primary completion
2019
Study completion
2019
First posted
Jun 18, 2019
Registry last updated
Nov 4, 2019

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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