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

Healthy Subjects Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03989518
• Other study ID #: 2019-00524
• Status: Completed
• Phase: N/A
• Start date: February 25, 2019
• Est. completion date: October 30, 2019

Study information

• Verified date: October 2019
• Source: Uppsala University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Description:

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 60
• Est. completion date: October 30, 2019
• Est. primary completion date: October 30, 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

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

Related Conditions & MeSH terms

• Healthy Subjects

Intervention

Behavioral:
• Fear acquisition
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
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
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.

Locations

Country	Name	City	State
Sweden	Uppsala University, Departement of Psychology	Uppsala

Sponsors (1)

Lead Sponsor	Collaborator
Uppsala University

Country where clinical trial is conducted

Sweden, 

References & Publications (1)

Agren T, Björkstrand J, Fredrikson M. Disruption of human fear reconsolidation using imaginal and in vivo extinction. Behav Brain Res. 2017 Feb 15;319:9-15. doi: 10.1016/j.bbr.2016.11.014. Epub 2016 Nov 10. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Task compliance	Questions asking participants to rate to what extent they followed the instructions during the experimental procedure on a scale ranging from 0 - 100 %.	Day 1
Other	Task compliance	Questions asking participants to rate to what extent they followed the instructions during the experimental procedure on a scale ranging from 0 - 100 %.	Day 2 (24 h after day 1)
Other	Task compliance	Questions asking participants to rate to what extent they followed the instructions during the experimental procedure on a scale ranging from 0 - 100 %.	Day 3 (48 h after day 1)
Primary	Skin conductance response (SCR)	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.	Day 1
Primary	Skin conductance response (SCR)	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.	Day 2 (24 h after day1)
Primary	Skin conductance response (SCR)	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.	Day 3 (48 h after day 1)
Secondary	Fear ratings	Ratings of subjective fear during the experimental procedure. Scale: 0 -100 (no fear at all - extreme fear)	Day 1
Secondary	State-Trait Anxiety Inventory	This is a self-rated questionnaire measuring trait anxiety. Higher scores indicate higher level of trait-anxiety (range 20-80)	Day 1
Secondary	Difficulties in emotion regulation scale	This is a self-rated questionnaire measuring difficulties in emotion regulation. Higher scores indicate higher level of difficulties in emotion regulation (range 36-180)	Day 1
Secondary	Fear ratings	Ratings of subjective fear during the experimental procedure. Scale: 0 -100 (no fear at all - extreme fear)	Day 2 (24 h after day 1)
Secondary	Vividness of mental imagery during imaginal extinction	Scale: 1-5; no image at all - image as clear and vivid as real life	Day 2 (24 h after day 1)
Secondary	The Plymouth Sensory Imagery Questionnaire	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)	Day 2 (24 h after day 1)
Secondary	The Vividness of Visual Imagery Questionnaire	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)	Day 2 (24 h after day 1)
Secondary	Spontaneous use of imagery scale	This is a self-rated questionnaire measuring spontaneous use of imagery. Higher scores higher levels use of spontaneous use of imagery (range 12- 60)	Day 2 (24 h after day 1)
Secondary	Expectancy ratings	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 %	Day 2 (24 h after day 1)
Secondary	Fear ratings	Ratings of subjective fear during the experimental procedure. Scale: 0 -100 (no fear at all - extreme fear)	Day 3 (48 h after day 1)
Secondary	Expectancy ratings	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 %	Day 3 (48 h after day 1)