Healthy Subjects
Conditions
Keywords
Imaginal extinction, imaginal exposure, mental imagery
Brief 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.
Detailed 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.
Interventions
BEHAVIORALFear 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).
BEHAVIORALImaginal 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.
BEHAVIORALReinstatement
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.
Sponsors
Uppsala University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Skin conductance response (SCR) | Day 1 | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Fear ratings | Day 1 | Ratings of subjective fear during the experimental procedure. Scale: 0 -100 (no fear at all - extreme fear) |
| State-Trait Anxiety Inventory | Day 1 | This is a self-rated questionnaire measuring trait anxiety. Higher scores indicate higher level of trait-anxiety (range 20-80) |
| Difficulties in emotion regulation scale | Day 1 | This is a self-rated questionnaire measuring difficulties in emotion regulation. Higher scores indicate higher level of difficulties in emotion regulation (range 36-180) |
| Vividness of mental imagery during imaginal extinction | Day 2 (24 h after day 1) | Scale: 1-5; no image at all - image as clear and vivid as real life |
| The Vividness of Visual Imagery Questionnaire | Day 2 (24 h after day 1) | 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) |
| Spontaneous use of imagery scale | Day 2 (24 h after day 1) | This is a self-rated questionnaire measuring spontaneous use of imagery. Higher scores higher levels use of spontaneous use of imagery (range 12- 60) |
| Expectancy ratings | Day 2 (24 h after day 1) | 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 % |
| The Plymouth Sensory Imagery Questionnaire | Day 2 (24 h after day 1) | 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) |
Other
| Measure | Time frame | Description |
|---|---|---|
| Task compliance | Day 1 | Questions asking participants to rate to what extent they followed the instructions during the experimental procedure on a scale ranging from 0 - 100 %. |
Countries
Sweden
Outcome results
None listed