Reward Processes and Rehearsal in Exposure Therapy

Study Overview
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Brief Summary
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The purpose of this study is to 1) examine the importance of self-reported relief following exposure and 2) test whether positive-focused rehearsal following exposure can improve treatment outcomes for participants who endorse fear of public speaking. Exposure therapy is an extinction-based behavioral technique, often employed in the context of cognitive behavioral therapy. It involves strategically exposing an individual to a feared stimulus in an effort to generate new non-fear associations with that stimulus. Relief refers to the positive, rewarding emotions associated with the absence of an expected aversive outcome following exposure to a feared stimulus. In the current study, participants will engage in a series of short public speaking exposures that take place over two sessions. After every two exposures, participants will be asked to complete either a positive or neutral rehearsal exercise, consisting of recalling either positive or neutral aspects of the speech exposures. At multiple points throughout the study, participants will complete ratings of reward sensitivity, positive affect, relief, and expectancy of the aversive outcome. The investigators will test the following: 1) the relationship of reward sensitivity and positive affect with relief following exposures, 2) the relationship between relief after exposure and learning rate (i.e., learning that the feared stimulus does not predict an aversive outcome), 3) potential differences in exposure outcomes between the positive and neutral rehearsal groups.

Detailed Description
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Treatment response rates for cognitive behavioral therapy (CBT) across anxiety disorders average approximately 50% post-treatment and at follow-up. Thus, recent research has amplified efforts toward improving treatment methodology in an attempt to optimize clinical outcomes. Many efforts have targeted exposure therapy, an evidence-based behavioral technique during which a participant is strategically and repeatedly exposed to a feared stimulus in order to generate new non-fear associations with that stimulus. Mechanisms of exposure therapy have been conceptualized using inhibitory retrieval models of extinction learning. These models, derived from Pavlovian conditioning, posit that extinction is dependent upon formation of an inhibitory association where the feared conditional stimulus (CS) no longer predicts the aversive unconditional stimulus (US). The new inhibitory CS-noUS association then competes with the original CS-US association. Research has demonstrated that greater expectation of US occurrence (US expectancy) followed by the unexpected omission of the US (i.e., expectancy violation) is associated with greater learning of the inhibitory association. Exposure therapy is a clinical proxy of extinction; in order to compete with the original association between public speaking (CS) and rejection (US), participants engage in repeated exposures to the CS without the US (no rejection) and form a new inhibitory association wherein public speaking no longer predicts rejection. Strategies to enhance this inhibitory learning process include mental rehearsal, where information from a previous exposure trial is recounted to reinforce the newly learned inhibitory association. There is also promising evidence which suggests that reward processes may facilitate extinction learning, though studies have yet to be conducted in a clinical sample. Experimental studies have demonstrated that greater relief, a positive emotion that occurs following US omission, is associated with greater expectancy violation. This suggests that positive emotions during exposure (e.g., relief) may directly influence the extinction learning process. Reduced positive affect has been associated with decreased updating of US expectancies, leading to slower learning during extinction. In contrast, elevated positive affect has been associated with enhanced encoding, rehearsal, and retrieval processes, which may lead to faster learning during extinction and prevent return of fear (i.e., relapse). Strategies designed to enhance reward sensitivity and positive affect may therefore be an important avenue of future research to improve exposure therapy outcomes. While not yet applied during exposure, strategies aimed to increase reward sensitivity via positive-focused rehearsal have led to decreased anxiety, depression, and negative affect and increased positive affect. Recent work has shown that rehearsal without a positive focus immediately following exposure leads to reductions in anxiety. Therefore, rehearsal following exposure that specifically focuses on positive emotions to increase reward sensitivity has the potential to lead to even greater symptom improvement. The current study seeks to examine the role of relief during extinction learning and to test whether positive-focused rehearsal exercise may be implemented to improve treatment outcomes in exposure therapy in a population of individuals who demonstrate excessive fear of public speaking. There are three main goals of the study: 1) examine the relationship of reward sensitivity and positive affect with relief following exposures, 2) examine the relationship between relief after exposure and learning rate (i.e., learning that the feared stimulus does not predict an aversive outcome), and 3) test the efficacy of a positive rehearsal exercise following exposure compared to a neutral rehearsal exercise. Participants will engage in a series of short public speaking exposures that take place over two sessions. After every two exposures, participants will be asked to complete either a positive or neutral rehearsal exercise, consisting of recalling either positive or neutral aspects of the speech exposures. At multiple points throughout the study, participants will complete ratings of reward sensitivity, positive affect, relief, and expectancy of the aversive outcome.

Official Title
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Reward Processes and Rehearsal in Exposure Therapy

Conditions
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Anxiety Disorders, Public Speaking Fear

Intervention / Treatment
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* Behavioral: Exposure
* Behavioral: Rehearsal


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: English-speaking Elevated score on public speaking anxiety/avoidance screening questions

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Positive Rehearsal<br>After every two exposure trials, participants will complete a rehearsal exercise prompting reflection of expectancy violation and rehearsal of the inhibitory association between the conditional stimulus (i.e., speech) and the unconditional stimulus (i.e., rejection). During rehearsal, participants are prompted to identify positive emotional experiences associated with exposure trial outcomes. | Behavioral: Exposure<br>* All participants complete two study visits, each consisting of 8 exposure trials for durations of 1 minute each, resulting in a total of 16 exposures. For each exposure, participants are assigned a speech topic and given 1 minute to give an unprepared speech to two study confederates.<br>Behavioral: Rehearsal<br>* After every two exposures, participants will complete a rehearsal task where the participant is asked to use a positive or neutral approach to remember and recount the exposures they have just completed.<br>|
| Active Comparator: Neutral Rehearsal<br>After every two exposure trials, participants will complete a rehearsal exercise prompting reflection of expectancy violation and rehearsal of the inhibitory association between the conditional stimulus (i.e., speech) and the unconditional stimulus (i.e., rejection). During rehearsal, participants are prompted to maintain a neutral, non-emotional stance and focus on overall exposure trial outcomes. | Behavioral: Exposure<br>* All participants complete two study visits, each consisting of 8 exposure trials for durations of 1 minute each, resulting in a total of 16 exposures. For each exposure, participants are assigned a speech topic and given 1 minute to give an unprepared speech to two study confederates.<br>Behavioral: Rehearsal<br>* After every two exposures, participants will complete a rehearsal task where the participant is asked to use a positive or neutral approach to remember and recount the exposures they have just completed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in public speaking anxiety | Responses to two self-reported questions assessing public speaking anxiety and avoidance (scored from 0-8, where higher scores reflect greater public speaking anxiety and avoidance) and responses to the Personal Report of Public Speaking Anxiety (PRPSA; scored from 34-170, where higher scores reflect greater public speaking anxiety symptom severity). | Baseline through study completion, an average of 3 weeks. | 
| Change in social anxiety | Self-reported symptom severity of social anxiety using the Liebowitz Social Anxiety Scale (LSAS; scored from 0-144 where higher scores reflect greater social anxiety symptom severity). | Baseline through study completion, an average of 3 weeks. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Learning rate | Change in self-reported US expectancy ratings over time. | Sessions 1 through 2, an average of 2 weeks. | 
| Relief rate | Change in self-reported relief ratings over time. | Sessions 1 through 2, an average of 2 weeks. | 
| Change in positive affect | Change in self-reported positive affect measured using a visual analog scale (scored from 1-9 where higher scores reflect greater positive affect). | Baseline through study completion, an average of 3 weeks. | 
| Change in reward sensitivity | Change in self-reported reward sensitivity using the Positive Valence System Scale (PVSS; scored from 21-189 where higher scores reflect greater reward sensitivity). | Baseline through study completion, an average of 3 weeks. | 
| Change in reward sensitivity | Change in self-reported reward sensitivity using the Behavioral Activation Scale (BAS) subscales (BAS-Reward Responsiveness is scored from 5-20, BAS-Drive and BAS-Fun-Seeking are scored from 4-16, and higher scores on all subscales reflect greater reward sensitivity). | Baseline through study completion, an average of 3 weeks. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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anxiety, extinction, positive affect, reward sensitivity