The Neural Mechanisms of Imaginal Extinction

NCT ID: NCT05168592

Last Updated: 2024-08-26

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 87 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-04-07
• Study Completion Date: 2023-03-01

Brief 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.

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).

Conditions

Fear of Spiders

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Imaginal extinction

Conditioned fear will be diminished using imaginal extinction.

Group Type: EXPERIMENTAL

Threat conditioning

Intervention Type: 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

Intervention Type: 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.

Interventions

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.

Intervention Type: 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.

Intervention Type: BEHAVIORAL

Eligibility Criteria

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).

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Uppsala University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Thoma Ågren, PhD

Role: PRINCIPAL_INVESTIGATOR

Uppsala University

Locations

The Swedish 7T facility

Lund, , Sweden

Countries

Sweden

Other Identifiers

2020-06930b

Identifier Type: -

Identifier Source: org_study_id