The Neural Mechanisms of Imaginal Extinction

Fear of Spiders Clinical Trial

Official title:

Exploring the Neural Mechanisms of Imaginal Extinction Using fMRI and Psychophysiology

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05168592
• Other study ID #: 2020-06930b
• Status: Recruiting
• Phase: N/A
• Start date: April 7, 2022
• Est. completion date: December 2022

Study information

• Verified date: April 2022
• Source: Uppsala University
• Contact: Thomas Ågren, PhD
• Phone: +46(0)184712124
• Email: thomas.agren[@]psyk.uu.se
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

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).

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 80
• Est. completion date: December 2022
• Est. primary completion date: December 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

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).

Related Conditions & MeSH terms

• Fear of Spiders

Intervention

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.
• 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.

Locations

Country	Name	City	State
Sweden	The Swedish 7T facility	Lund

Sponsors (1)

Lead Sponsor	Collaborator
Uppsala University

Country where clinical trial is conducted

Sweden, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Blood oxygen level dependent contrast (BOLD-signal) during threat conditioning and imaginal extinction.	BOLD-signal is assessed using functional magnetic resonance imaging.	Day 1
Primary	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	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
Secondary	Ratings of subjective fear experienced during threat conditioning and imaginal extinction.	Scale 0-100; no fear at all - extreme fear	Day 1
Secondary	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
Secondary	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