Effects of Expectations on Negative Affect, Perceived Cognitive Effort, and Pain
Study Details
Study Description
Brief 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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Pain: High Cue Prior to experiencing the pain stimulus, 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 sensation" to "strongest sensation of any kind." In the high cue condition, 10 data points are randomly extracted from a beta distribution, Beta(ɑ = 0.6, β = 0.85), for the semi-circle. |
Behavioral: Expectancy Cues
Participants are presented with a social cue that represents how previous participants responded to the upcoming stimulus. In actuality, the cue is a social placebo, constructed by the experimenters and varying in intensity.
|
| Experimental: Pain: Low Cue Prior to experiencing the pain stimulus, 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 sensation" to "strongest sensation of any kind." In the low cue condition, 10 data points randomly extracted from a beta distribution, Beta(ɑ = 0.1, β = 2), for the semi-circle. |
Behavioral: Expectancy Cues
Participants are presented with a social cue that represents how previous participants responded to the upcoming stimulus. In actuality, the cue is a social placebo, constructed by the experimenters and varying in intensity.
|
| Experimental: Vicarious: High Cue Prior to experiencing the vicarious stimulus, 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 sensation" to "strongest sensation of any kind." In the high cue condition, 10 data points are randomly extracted from a beta distribution, Beta(ɑ = 0.6, β = 0.85), for the semi-circle. |
Behavioral: Expectancy Cues
Participants are presented with a social cue that represents how previous participants responded to the upcoming stimulus. In actuality, the cue is a social placebo, constructed by the experimenters and varying in intensity.
|
| Experimental: Vicarious: Low Cue Prior to experiencing the vicarious stimulus, 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 sensation" to "strongest sensation of any kind." In the low cue condition, 10 data points randomly extracted from a beta distribution, Beta(ɑ = 0.1, β = 2), for the semi-circle. |
Behavioral: Expectancy Cues
Participants are presented with a social cue that represents how previous participants responded to the upcoming stimulus. In actuality, the cue is a social placebo, constructed by the experimenters and varying in intensity.
|
| Experimental: Cognitive Effort: High Cue Prior to experiencing the cognitive effort stimulus, 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." In the high cue condition, 10 data points are randomly extracted from a beta distribution, Beta(ɑ = 0.6, β = 0.85), for the semi-circle. |
Behavioral: Expectancy Cues
Participants are presented with a social cue that represents how previous participants responded to the upcoming stimulus. In actuality, the cue is a social placebo, constructed by the experimenters and varying in intensity.
|
| Experimental: Cognitive Effort: Low Cue Prior to experiencing the cognitive effort stimulus, 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." In the low cue condition, 10 data points randomly extracted from a beta distribution, Beta(ɑ = 0.1, β = 2), for the semi-circle. |
Behavioral: Expectancy Cues
Participants are presented with a social cue that represents how previous participants responded to the upcoming stimulus. In actuality, the cue is a social placebo, constructed by the experimenters and varying in intensity.
|
Outcome Measures
Primary Outcome Measures
- Behavioral: Within participant changes in subjective experience of stimulus intensity [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.]
After each stimulus delivery, participants are prompted to indicate the intensity of their stimulus experience ("outcome ratings"), 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"). Low scores indicate that the participant perceived the stimulus to be of weak intensity, while high scores indicate the participant perceived the stimulus to be of high intensity. The investigators will compare the ratings within each task, as a function of stimulus intensity.
- fMRI: Within participant changes in brain signals as a function of stimulus intensity [Measured continuously during stimulus delivery, 1 hour of fMRI scanning. Each scan is conducted across 3 sessions.]
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.
- Behavioral: Within participant changes in subjective experience of cue-established expectations [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.]
After each cue presentation, participants experience an actual stimulus and are prompted to report outcome ratings. 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 compare the expectations ratings as a function of cue. The investigators will also compare the outcome ratings as a function of cue.
- fMRI: Within participant changes in brain signals as a function of high vs low cue [Measured continuously during stimulus delivery, 1 hour of fMRI scanning. Each scan is conducted across 3 sessions.]
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.
Secondary Outcome Measures
- Within participant changes in heart rate meaured with a Biopac MP150 device [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.]
Each session of the experiment includes somatic pain, vicarious pain, cognitive effort tasks, in which multiple stimuli are delivered. Heart rate will be measured continuously. The investigators will compare the heart rate in response to stimuli delivery as a function high vs. low cue presentation.
- Within participant changes in skin conductance response meaured with a Biopac MP150 device [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.]
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. The investigators will compare the heart rate in response to stimuli delivery as a function high vs. low cue presentation.
Eligibility Criteria
Criteria
Inclusion Criteria:
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Capable of performing experimental tasks (e.g., are able to read, can tolerate the maximum level of thermal pain stimuli).
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Fluent or native speakers of English
Exclusion Criteria:
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Contraindications to magnetic resonance scanning (e.g., metal in body, claustrophobia, pregnancy)
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Substance abuse within the last six months
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Current or recent history of pathological pain
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Current or recent history of neurological disorders
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Currently or recent history of chronic pain
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Left-handed only
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Dartmouth College | Hanover | New Hampshire | United States | 03755 |
Sponsors and Collaborators
- Trustees of Dartmouth College
- National Institutes of Health (NIH)
Investigators
- Principal Investigator: Tor D Wager, PhD, Dartmouth College
Study Documents (Full-Text)
More Information
Publications
None provided.- STUDY00031937