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

Placebo Clinical Trial

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

Status Completed

Clinical Trial 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 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.

Clinical Trial Description

n/a

Related Conditions & MeSH terms

• Expectations
• Placebo

• NCT number: NCT05425563
• Study type: Interventional
• Source: Trustees of Dartmouth College
• Status: Completed
• Phase: N/A
• Start date: November 23, 2020
• Completion date: January 19, 2023