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

Trustees of Dartmouth College

Status: Completed

Conditions: Expectations; Placebo

Treatments: Behavioral: Pain Expectancy Cues; Behavioral: Vicarious Pain Expectancy Cues; Behavioral: Cognitive Effort Expectancy Cues

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT05425563

STUDY00031937

5R01MH076136 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

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.

Enrollment: 133 patients

Sex: All

Ages: 18 to 55 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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133 participants in 1 patient group

Cue-established expectations

Experimental group

Description:

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.

Treatment:

Behavioral: Vicarious Pain Expectancy Cues

Behavioral: Pain Expectancy Cues

Behavioral: Cognitive Effort Expectancy Cues