Expectancy Cues for Placebos

Phase-Based Progress Estimates
1
Effectiveness
1
Safety
Dartmouth College, Hanover, NH
Placebos+1 More
Expectancy Cues - Behavioral
Eligibility
18 - 65
All Sexes
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Study Summary

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 task incorporates three conditions in which participants experience and rate 1) somatic pain, 2) vicarious pain, and 3) cognitive effort. In the somatic pain condition, participants receive a brief thermal stimulus administered to a site on their arm; in the vicarious pain condition, participants watch a short video clip of a patient with back/shoulder pain; in the cognitive effort condition, 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.

Eligible Conditions

  • Placebos
  • Expectations

Treatment Effectiveness

Effectiveness Progress

1 of 3

Study Objectives

4 Primary · 2 Secondary · Reporting Duration: Measured continuously during stimulus delivery, 1 hour of fMRI scanning. Each scan is conducted across 3 sessions.

Measured continuously during each task, concurrent with stimulus delivery. Each task is distributed across 3 sessions. Within each task, we plan to average heart rate across sessions.
Within participant changes in heart rate meaured with a Biopac MP150 device
Within participant changes in skin conductance response meaured with a Biopac MP150 device
Hour 1
fMRI: Within participant changes in brain signals as a function of high vs low cue
fMRI: Within participant changes in brain signals as a function of stimulus intensity
Measured repeatedly during each task, immediately after cue presentation. Each task is distributed across 3 sessions. Within each task, we plan to average ratings across sessions, as a function of cue.
Behavioral: Within participant changes in subjective experience of cue-established expectations
Measured repeatedly during each task, immediately after stimulus delivery. Each task is distributed across 3 sessions. Within each task, the investigators plan to average ratings across sessions.
Behavioral: Within participant changes in subjective experience of stimulus intensity

Trial Safety

Trial Design

6 Treatment Groups

Cognitive Effort: High Cue
1 of 6
Pain: High Cue
1 of 6
Pain: Low Cue
1 of 6
Vicarious: High Cue
1 of 6
Vicarious: Low Cue
1 of 6
Cognitive Effort: Low Cue
1 of 6
Experimental Treatment

185 Total Participants · 6 Treatment Groups

Primary Treatment: Expectancy Cues · No Placebo Group · N/A

Cognitive Effort: High Cue
Behavioral
Experimental Group · 1 Intervention: Expectancy Cues · Intervention Types: Behavioral
Pain: High Cue
Behavioral
Experimental Group · 1 Intervention: Expectancy Cues · Intervention Types: Behavioral
Pain: Low Cue
Behavioral
Experimental Group · 1 Intervention: Expectancy Cues · Intervention Types: Behavioral
Vicarious: High Cue
Behavioral
Experimental Group · 1 Intervention: Expectancy Cues · Intervention Types: Behavioral
Vicarious: Low Cue
Behavioral
Experimental Group · 1 Intervention: Expectancy Cues · Intervention Types: Behavioral
Cognitive Effort: Low Cue
Behavioral
Experimental Group · 1 Intervention: Expectancy Cues · Intervention Types: Behavioral

Trial Logistics

Trial Timeline

Approximate Timeline
Screening: ~3 weeks
Treatment: Varies
Reporting: measured continuously during stimulus delivery, 1 hour of fmri scanning. each scan is conducted across 3 sessions.
Closest Location: Dartmouth College · Hanover, NH
Photo of new hampshire 1Photo of new hampshire 2Photo of new hampshire 3
2017First Recorded Clinical Trial
1 TrialsResearching Placebos
6 CompletedClinical Trials

Who is running the clinical trial?

National Institutes of Health (NIH)NIH
2,390 Previous Clinical Trials
24,521,372 Total Patients Enrolled
Trustees of Dartmouth CollegeLead Sponsor
20 Previous Clinical Trials
9,192 Total Patients Enrolled
Tor D Wager, PhDPrincipal InvestigatorDartmouth College
5 Previous Clinical Trials
400 Total Patients Enrolled

Eligibility Criteria

Age 18 - 65 · All Participants · 2 Total Inclusion Criteria

Mark “yes” if the following statements are true for you:
You are capable of performing experimental tasks.

About The Reviewer

Michael Gill preview

Michael Gill - B. Sc.

First Published: October 9th, 2021

Last Reviewed: August 12th, 2022

Michael Gill holds a Bachelors of Science in Integrated Science and Mathematics from McMaster University. During his degree he devoted considerable time modeling the pharmacodynamics of promising drug candidates. Since then, he has leveraged this knowledge of the investigational new drug ecosystem to help his father navigate clinical trials for multiple myeloma, an experience which prompted him to co-found Power Life Sciences: a company that helps patients access randomized controlled trials.