Clinical trial NCT05168592: The Neural Mechanisms of Imaginal Extinction
Official title: Exploring the Neural Mechanisms of Imaginal Extinction Using fMRI and Psychophysiology
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Fear of Spiders
Keywords: Threat conditioning
Extinction
Imaginal Extinction
Mental Imagery
Lead sponsor: Uppsala University
Sponsor class: OTHER
First posted: 2021-12-23
Enrollment: 87
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

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).

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).

Primary outcomes:
measure: Blood oxygen level dependent contrast (BOLD-signal) during threat conditioning and imaginal extinction.
timeFrame: Day 1
measure: Physiological arousal response during threat conditioning and imaginal extinction.
timeFrame: Day 1
Secondary outcomes:
measure: Task-specific mental imagery vividness during imaginal extinction
timeFrame: Day 1
measure: Ratings of subjective fear experienced during threat conditioning and imaginal extinction.
timeFrame: Day 1
measure: Spielberger State-Trait Anxiety Inventory (STAI-T)
timeFrame: One week after Day 1
measure: Vividness of visual imagery Questionnaire (VVIQ)
timeFrame: One week after Day 1
Other outcomes:
Locations:
city: Lund
country: Sweden
facility: The Swedish 7T facility
Study officials:
affiliation: Uppsala University
name: Thoma Ågren, PhD
role: PRINCIPAL_INVESTIGATOR
References: