Effects of Expectations on Negative Affect, Perceived Cognitive Effort, and Pain

Study Overview
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Brief Summary
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The investigators administer a functional neuroimaging task to investigate the effect of cue expectancy on participants' self-reported ratings across a variety of affective and cognitive domains. The experiment incorporates three tasks in which participants experience and rate 1) somatic pain, 2) vicarious pain, and 3) cognitive effort. In the somatic pain task, participants receive a brief thermal stimulus administered to a site on their arm; in the vicarious pain task, participants watch a short video clip of a patient with back/shoulder pain; in the cognitive effort task, participants perform a cognitively demanding mental rotation task that requires them to indicate whether two 3D objects are the same or different when rotated along the y-axis. Each trial follows a sequence that begins with a fixation, followed by a social influence cue, then an expectation rating, followed by a condition-specific stimulus, and then, an actual rating of the outcome experience. There are four events of interest: 1) cue perception, 2) expectation rating, 3) stimulus experience, and 4) outcome rating. First, participants are presented with a cue that depicts how other participants responded to the upcoming stimulus (cue perception). Although the participant is told these are real ratings, they are in fact, fabricated data points that vary in intensity (low, high). Then, based on the provided cues, participants are prompted to report their expectation of the upcoming stimulus intensity (expectation rating) After providing an expectation rating, participants are presented with a condition-specific stimulus (somatic pain, vicarious pain, or cognitive effort) that also varies in three levels of low, medium, high stimulus intensity (stimulus experience). Once the stimulus presentation has concluded, participants are prompted to provide an actual rating of their experience (outcome rating). For the somatic pain condition, participants rate their expectations and actual experience of how painful the stimulus was; for the vicarious pain condition, they rate their expectations and actual perception of how much pain the patient was in; and for the cognitive condition, the participant provides expectation and actual ratings of task difficulty.

Official Title
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Effects of Expectations on Negative Affect, Perceived Cognitive Effort, and Pain

Conditions
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Placebo, Expectations

Intervention / Treatment
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* Behavioral: Pain Expectancy Cues
* Behavioral: Vicarious Pain Expectancy Cues
* Behavioral: Cognitive Effort Expectancy Cues


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Capable of performing experimental tasks (e.g., are able to read, can tolerate the maximum level of thermal pain stimuli). Fluent or native speakers of English Exclusion Criteria: Contraindications to magnetic resonance scanning (e.g., metal in body, claustrophobia, pregnancy) Substance abuse within the last six months Current or recent history of pathological pain Current or recent history of neurological disorders Currently or recent history of chronic pain Left-handed only

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: Within-participant design with behavioral manipulations
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cue-established expectations<br>Prior to experiencing the stimuli from three tasks (somatic pain/cognitive effort/vicarious pain), the participant is presented with an expectancy cue. The cue depicts 10 data points on a semi-circular scale (0-180 degrees) with categorical labels ranging from no effort to strongest effort of any kind. Subsequently, participants report expectation ratings and outcome ratings. | Behavioral: Pain Expectancy Cues<br>* Participants are presented with a social cue that represents how previous participants responded to the upcoming somatic pain stimulus. In actuality, the cue is a social placebo, constructed by the experimenters and varying in intensity.<br>Behavioral: Vicarious Pain Expectancy Cues<br>* Participants are presented with a social cue that represents how previous participants responded to the upcoming vicarious pain stimulus. In actuality, the cue is a social placebo, constructed by the experimenters and varying in intensity.<br>Behavioral: Cognitive Effort Expectancy Cues<br>* Participants are presented with a social cue that represents how previous participants responded to the upcoming cognitive effort stimulus. In actuality, the cue is a social placebo, constructed by the experimenters and varying in intensity.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Behavioral: Within Participant Subjective Outcome Ratings of Acute Thermal Pain Following High Compared to Low Cues | The outcome measure is the subjective outcome rating for perceived pain. In each session, participants undergo pain tasks with multiple thermal stimuli. After each stimulus, participants rate their perceived pain on a semi-circular scale (0-180°). Higher angles indicate greater perceived pain. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average rating after high cue and after low cue. The final outcome is the difference between these averages, forming a contrast score that reflects the average difference in perceived pain as a function of high and low cue exposure. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened pain perception. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, and contrasted to a single outcome measure: perceived pain as a function of high low cue exposure. | 
| Behavioral: Within Participant Subjective Outcome Ratings of Vicarious Pain Following High Compared to Low Cues | The outcome measure is the subjective outcome rating for perceived vicarious pain. In each session, participants undergo vicarious pain tasks, watching multiple videos of patients in pain. After each stimulus, participants rate their perceived vicarious pain on a semi-circular scale (0-180°). Higher angles indicate that participants perceived greater pain for the patient in video. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average outcome rating after high cue and after low cue. The final outcome is the difference between these averages, forming a contrast score that reflects the average difference in perceived vicarious pain as a function of high and low cue exposure. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened perception of vicarious pain. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, and contrasted to a single outcome measure: perceived vicarious pain as a function of high low cue exposure. | 
| Behavioral: Within Participant Subjective Ratings of Cognitive Effort Following High Compared to Low Cues | The outcome measure is the subjective outcome rating for cognitive effort. In each session, participants undergo cognitive effort task where images of mentally rotated figures are presented. After each stimulus, participants rate their perceived cognitive effort on a semi-circular scale (0-180°). Higher angles indicate greater perceived of cognitive effort. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average outcome rating after high cue and after low cue. The final outcome is the difference between these averages, forming a contrast score that reflects the average difference in perceived cognitive effort as a function of high and low cue exposure. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened perception of cognitive effort.. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, and contrasted to a single outcome measure: perceived cognitive effort as a function of high low cue exposure. | 
| Behavioral: Within Participant Subjective Outcome Ratings of Acute Thermal Pain Following High Cues | This outcome measure is the least metabolized data of subjective outcome rating for perceived pain. In each session, participants undergo pain tasks with multiple thermal stimuli. After each stimulus, participants rate their perceived pain on a semi-circular scale (0-180°). Higher angles indicate greater perceived pain. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average rating after high cue and after low cue. Reported here is the average subjective outcome rating, post-high cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened pain perception. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting: perceived pain as a function of high cue exposure. | 
| Behavioral: Within Participant Subjective Outcome Ratings of Acute Thermal Pain Following Low Cues | This outcome measure is the least metabolized data of subjective outcome rating for perceived pain. In each session, participants undergo pain tasks with multiple thermal stimuli. After each stimulus, participants rate their perceived pain on a semi-circular scale (0-180°). Higher angles indicate greater perceived pain. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average rating after high cue and after low cue. Reported here is the average subjective outcome rating post-low cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened pain perception. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting: perceived pain as a function of low cue exposure. | 
| Behavioral: Within Participant Subjective Outcome Ratings of Vicarious Pain Following High Cues | The outcome measure is the least metabolized data of subjective outcome rating for perceived vicarious pain. In each session, participants undergo vicarious pain tasks, watching multiple videos of patients in pain. After each stimulus, participants rate their perceived vicarious pain on a semi-circular scale (0-180°). Higher angles indicate that participants perceived greater pain for the patient in video. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average outcome rating after high cue and after low cue. Reported here is the average subjective outcome rating post high cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened perception of vicarious pain. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting: perceived pain as a function of high cue exposure. | 
| Behavioral: Within Participant Subjective Outcome Ratings of Vicarious Pain Following Low Cues | The outcome measure is the least metabolized data of subjective outcome rating for perceived vicarious pain. In each session, participants undergo vicarious pain tasks, watching multiple videos of patients in pain. After each stimulus, participants rate their perceived vicarious pain on a semi-circular scale (0-180°). Higher angles indicate that participants perceived greater pain for the patient in video. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average outcome rating after high cue and after low cue. Reported here is the average subjective outcome rating post low cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened perception of vicarious pain. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting: perceived pain as a function of low cue exposure. | 
| Behavioral: Within Participant Subjective Ratings of Cognitive Effort Following High Cues | The outcome measure is the least metabolized data of subjective outcome rating for cognitive effort. In each session, participants undergo cognitive effort task where images of mentally rotated figures are presented. After each stimulus, participants rate their perceived cognitive effort on a semi-circular scale (0-180°). Higher angles indicate greater perceived of cognitive effort. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average outcome rating after high cue and after low cue. Reported here is the average subjective outcome rating post high cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened perception of cognitive effort. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting: perceived pain as a function of high cue exposure. | 
| Behavioral: Within Participant Subjective Ratings of Cognitive Effort Following Low Cues | The outcome measure is the least metabolized data of subjective outcome rating for cognitive effort. In each session, participants undergo cognitive effort task where images of mentally rotated figures are presented. After each stimulus, participants rate their perceived cognitive effort on a semi-circular scale (0-180°). Higher angles indicate greater perceived of cognitive effort. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average outcome rating after high cue and after low cue. Reported here is the average subjective outcome rating post low cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened perception of cognitive effort. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting: perceived pain as a function of low cue exposure. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Behavioral: Within Participant Expectation Ratings of Acute Thermal Pain Following High Compared to Low Cues | The outcome measure is the expectation rating for upcoming pain. In each session, participants undergo pain tasks with multiple thermal stimuli. Before each stimulus, participants see a high or low cue and rate their pain expectation on a semi-circular scale (0-180°). Higher angles indicate greater pain expectations. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average rating after high cue and after low cue. The final outcome is the difference between these averages, forming a contrast score that reflects the variance in pain expectations between cues. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened expectations for thermal pain intensity. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, and contrasted to a single outcome measure: expectations of pain as a function of high low cue exposure. | 
| Behavioral: Within Participant Expectation Ratings of Vicarious Pain Following High Compared to Low Cues | The outcome measure is the expectation rating for upcoming vicarious pain. In each session, participants undergo vicarious pain tasks, watching multiple videos of patients in pain. Prior to each stimulus, participants see a high or low cue and rate their expectation of perceived vicarious pain for an upcoming stimulus experience on a semi-circular scale (0-180°). Higher angles suggest participants anticipate viewing videos of patients experiencing greater pain. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average expectation rating after high cue and after low cue. The final outcome is the difference between these averages, forming a contrast score that reflects difference in vicarious pain expectations between cues. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened expectations for vicarious pain intensity. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, and contrasted to a single outcome measure: expectations of vicarious pain as a function of high low cue exposure. | 
| Behavioral: Within Participant Expectation Ratings of Cognitive Effort Following High Compared to Low Cues | The outcome measure is the expectation rating for upcoming cognitive effort. In each session, participants undergo cognitive effort tasks where images of mentally rotated figures are presented. Before each stimulus, participants see a high or low cue and rate their expectations on cognitive effort on a semi-circular scale (0-180°). Higher angles indicate greater expectations of cognitive effort. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average expectation rating after high cue and after low cue. The final outcome is the difference between these averages, forming a contrast score that reflects the difference in cognitive effort expectations between cues. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened expectations of cognitive effort. | Within trials, outcome ratings are collected post-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, and contrasted to a single outcome measure: expectations of cognitive effort as a function of high low cue exposure. | 
| Behavioral: Within Participant Expectations Ratings of Acute Thermal Pain Following High Cues | The outcome measure is the least metabolized data of expectation rating for upcoming pain. In each session, participants undergo pain tasks with multiple thermal stimuli. Before each stimulus, participants see a high or low cue and rate their pain expectation on a semi-circular scale (0-180°). Higher angles indicate greater pain expectations. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average rating after high cue and after low cue. Reported here is the average expectation rating, post-high cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened expectations for thermal pain intensity. | Within trials, outcome ratings are collected pre-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, and contrasted to a single outcome measure: expectations of pain as a function of high cue exposure. | 
| Behavioral: Within Participant Expectations Ratings of Acute Thermal Pain Following Low Cues | The outcome measure is the least metabolized data of expectation rating for upcoming pain. In each session, participants undergo pain tasks with multiple thermal stimuli. Before each stimulus, participants see a high or low cue and rate their pain expectation on a semi-circular scale (0-180°). Higher angles indicate greater pain expectations. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average rating after high cue and after low cue. Reported here is the average expectation rating, post-low cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened expectations for thermal pain intensity. | Within trials, outcome ratings are collected pre-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, and contrasted to a single outcome measure: expectations of pain as a function of low cue exposure. | 
| Behavioral: Within Participant Expectation Ratings of Vicarious Pain Following High Cues | The outcome measure is the least metabolized data of expectation rating for upcoming vicarious pain. In each session, participants undergo vicarious pain tasks, watching multiple videos of patients in pain. Prior to each stimulus, participants see a high or low cue and rate their expectation of perceived vicarious pain for an upcoming stimulus experience on a semi-circular scale (0-180°). Higher angles suggest participants anticipate viewing videos of patients experiencing greater pain. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average expectation rating after high cue and after low cue. Reported here is the average expectation rating, post-high cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened expectations for vicarious pain intensity. | Within trials, outcome ratings are collected pre-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting perceived vicarious pain as a function of high cue exposure. | 
| Behavioral: Within Participant Expectation Ratings of Vicarious Pain Following Low Cues | The outcome measure is the least metabolized data of expectation rating for upcoming vicarious pain. In each session, participants undergo vicarious pain tasks, watching multiple videos of patients in pain. Prior to each stimulus, participants see a high or low cue and rate their expectation of perceived vicarious pain for an upcoming stimulus experience on a semi-circular scale (0-180°). Higher angles suggest participants anticipate viewing videos of patients experiencing greater pain. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average expectation rating after high cue and after low cue. Reported here is the average expectation rating, post-low cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened expectations for vicarious pain intensity. | Within trials, outcome ratings are collected pre-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting perceived vicarious pain as a function of low cue exposure. | 
| Behavioral: Within Participant Expectation Ratings of Cognitive Effort Following High Cues | The outcome measure is the least metabolized data of expectation rating for upcoming cognitive effort. In each session, participants undergo cognitive effort tasks where images of mentally rotated figures are presented. Before each stimulus, participants see a high or low cue and rate their expectations on cognitive effort on a semi-circular scale (0-180°). Higher angles indicate greater expectations of cognitive effort. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average expectation rating after high cue and after low cue. Reported here is the average expectation rating, post-high cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened expectations for cognitive effort. | Within trials, outcome ratings are collected pre-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting: perceived pain as a function of high cue exposure. | 
| Behavioral: Within Participant Expectation Ratings of Cognitive Effort Following Low Cues | The outcome measure is the least metabolized data of expectation rating for upcoming cognitive effort. In each session, participants undergo cognitive effort tasks where images of mentally rotated figures are presented. Before each stimulus, participants see a high or low cue and rate their expectations on cognitive effort on a semi-circular scale (0-180°). Higher angles indicate greater expectations of cognitive effort. The Outcome Measure Calculation: Ratings are grouped by cue type: High or Low. Data points in each group are averaged across sessions, yielding two measures: average expectation rating after high cue and after low cue. Reported here is the average expectation rating, post-low cue. Scale: 0-180° Min value: 0 Max value: 180 Higher scores indicate heightened expectations for cognitive effort. | Within trials, outcome ratings are collected pre-stimulus (4s window); Trials are collected across 3 sessions. Ratings are then averaged, reflecting: perceived pain as a function of low cue exposure. | 
| Physiological: Within Participant Changes in Skin Conductance Response Measured With a Physiological Data Acquisition Device | Each session of the experiment includes somatic pain, vicarious pain, cognitive effort tasks, in which multiple stimuli are delivered. Skin conductance response will be measured continuously, using a physiological data acquisition device, Biopac MP150. The investigators will compare the skin conductance rate in response to stimuli delivery as a function high vs. low cue presentation. | Measured continuously during each task, concurrent with stimulus delivery. Each task is distributed across 3 sessions. Within each task, we plan to average skin conductance rate across sessions. | 
| Physiological: Within Participant Changes in Skin Conductance Rate Measured With a Physiological Data Acquisition Device | Each session of the experiment includes somatic pain, vicarious pain, cognitive effort tasks, in which multiple stimuli are delivered. Skin conductance rate will be measured continuously, using a physiological data acquisition device, Biopac MP150. The investigators will compare the skin conductance rate in response to stimuli delivery as a function high vs. low cue presentation. | Measured continuously during each task, concurrent with stimulus delivery. Each task is distributed across 3 sessions. Within each task, we plan to average skin conductance rate across sessions. | 
| Functional Magnetic Resonance Imaging (fMRI): Within Participant Changes in Brain Signals as a Function of Stimulus Intensity | After each stimulus delivery, participants are prompted to indicate outcome ratings, i.e. the intensity of their stimulus experience. Ratings are recorded on a semi-circular scale (0-180 degrees), with categorical labels indicated on the scale (e.g. no sensation to strongest sensation of any kind). The investigators will analyze stimulus brain signal as a function of high vs. med vs. low stimulus intensity. We plan to construct contrasts of stimulus brain maps based on stimulus intensity of high vs. med vs. low. | Measured continuously during stimulus delivery, 1 hour of functional magnetic resonance imaging scanning. Each scan is conducted across 3 sessions. | 
| Functional Magnetic Resonance Imaging (fMRI): Within Participant Changes in Brain Signals as a Function of High vs Low Cue | Investigator will model the brain event of each stimulus delivery event. From this, investigator will construct contrasts between stimulus brain maps as a function of high vs. low cue. Within each task of somatic pain, vicarious pain, and cognitive effort, we plan to both 1) average brain signals and 3) also isolate each event for further analyses. | Measured continuously during stimulus delivery, 1 hour of functional magnetic resonance imaging scanning. Each scan is conducted across 3 sessions. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Social Placebo, Somatic Pain, Vicarious Pain, Cognitive Effort