The Neural Mechanisms of Imaginal Extinction

Exploring the Neural Mechanisms of Imaginal Extinction Using fMRI and Psychophysiology

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.

Study Overview

• Status: Recruiting
• Conditions: Fear of Spiders
• Intervention / Treatment: Behavioral: Threat conditioning; Behavioral: Imaginal extinction

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).

• Study Type: Interventional
• Enrollment (Anticipated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Thomas Ågren, PhD; Phone Number: +46(0)184712124; Email: thomas.agren@psyk.uu.se
• Study Contact Backup: Name: Johannes Björkstrand, PhD; Email: johannes.bjorkstrand@psy.lu.se

Study Locations

• Sweden
  • Lund, Sweden, 22242
    • Recruiting
    • The Swedish 7T facility
    • Contact: Karin Markenroth Bloch, PhD; Email: karin.markenroth@med.lu.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Imaginal extinction; Conditioned fear will be diminished using imaginal extinction.

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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood oxygen level dependent contrast (BOLD-signal) during threat conditioning and imaginal extinction.	BOLD-signal is assessed using functional magnetic resonance imaging.	Day 1
Physiological arousal response during threat conditioning and imaginal extinction.	Skin conductance responses are used as a measure of physiological arousal response (i.e. event-related rise in electrodermal activity to stimuli).	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Task-specific mental imagery vividness during imaginal extinction	Vividness of Imagery (scale:1-5; no image at all - image as clear and vivid as real life)	Day 1
Ratings of subjective fear experienced during threat conditioning and imaginal extinction.	Scale 0-100; no fear at all - extreme fear	Day 1
Spielberger State-Trait Anxiety Inventory (STAI-T)	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.	One week after Day 1
Vividness of visual imagery Questionnaire (VVIQ)	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.	One week after Day 1

Collaborators and Investigators

• Sponsor: Uppsala University
• Investigators: Principal Investigator: Thoma Ågren, PhD, Uppsala University

Study record dates

Study Major Dates

• Study Start (Actual): April 7, 2022
• Primary Completion (Anticipated): December 1, 2022
• Study Completion (Anticipated): December 1, 2022

Study Registration Dates

• First Submitted: December 9, 2021
• First Submitted That Met QC Criteria: December 9, 2021
• First Posted (Actual): December 23, 2021

Study Record Updates

• Last Update Posted (Actual): April 11, 2022
• Last Update Submitted That Met QC Criteria: April 8, 2022
• Last Verified: April 1, 2022

More Information

Terms related to this study

• Keywords: Extinction; Mental Imagery; Threat conditioning; Imaginal Extinction
• Other Study ID Numbers: 2020-06930b

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: We plan to share anonymous behavioural and brain imaging data, training material, Statistical Analysis plan, and informed consent form on the project site on Open Science Framework (https://osf.io/s54dz/).
• IPD Sharing Time Frame: Data will be available from completion of analysis and publication, and onwards.
• IPD Sharing Access Criteria: Anonymous behavioural and brain imaging data, training material, and Statistical Analysis plan will be made public on the project site on Open Science Framework (https://osf.io/s54dz/)
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No