N-of-few Study of Pain Perception

Not Applicable

Completed

• Conditions: Healthy
• Interventions: Behavioral: Symbolic conditioning; Behavioral: Conditioning; Behavioral: Instructions; Behavioral: Counterfactual

• Registration Number: NCT04664400
• Lead Sponsor: Trustees of Dartmouth College

Brief Summary

A behavioral study that will examine how pain perception is affected by different types of conditioning and by context, with a few participants and multiple sessions ("N-of-few" design).

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2020-11-16
• Study First Submitted QC: 2020-12-10
• Study First Posted: 2020-12-11
• Study Start: 2021-01-22
• Primary Completion: 2021-05-24
• Study Completion: 2021-05-24
• Results First Submitted: 2022-08-09
• Results First Submitted QC: 2022-10-24
• Results First Posted: 2022-11-18
• Status Verified: 2023-04
• Last Update Submitted: 2023-04-13
• Last Update Posted: 2023-04-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 10

Inclusion Criteria

• Healthy participants

Exclusion Criteria

• Cannot tolerate heat pain applied to the forearm/leg, based on a calibration task at the beginning of the experiment

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
N-of-few Study of Pain	Symbolic conditioning	-
N-of-few Study of Pain	Instructions	-
N-of-few Study of Pain	Conditioning	-
N-of-few Study of Pain	Counterfactual	-

Primary Outcome Measures

Name	Time	Method
Within Participant Subjective Ratings of Acute Thermal Pain Following High Compared to Low Cues (Learned Via Instructions Only)	Measured repeatedly during pain tasks, in each of the 10 sessions of the experiment (up to 3 sessions per week, depending on the participants' availability), immediately after thermal stimuli. Averaged across sessions and compared across conditions.	Each session of the experiment includes pain tasks, in which multiple thermal stimuli are delivered. Following each thermal stimulus, participants are asked to rate how painful it was, on a semi-circular computerized scale. Ratings are based on the angle (0-180), with higher angle representing higher pain ratings. In the instructions only condition, cues are learned via verbal suggestion. For the cues that were learned via instructions only, the investigators will compare the average rating of pain for stimuli that are preceded by high cues minus the average rating of pain for stimuli that are preceded by low cues (each averaged across sessions), within participant.
Within Participant Subjective Ratings of Acute Thermal Pain, When it is the Worse vs. the Better Alternative	Measured repeatedly during pain tasks, in each of the last 4 sessions of the experiment, immediately after thermal stimuli. Averaged across sessions and compared across conditions.	In the counterfactual task, participants are presented with two alternatives (either two pain levels, or one pain level and either losing or gaining a certain amount of money). In these pairs of alternatives, the medium level pain is sometimes the better option (i.e., when the alternative is losing money or a more intense pain stimulus) and sometimes the worse option (i.e., when the other alternative is gaining money or a less intense pain stimulus). One of the two options is chosen by the computer (participants have no control on this choice). The investigators will compare the pain ratings (scale 0-180) within participant for the same level pain stimulus (medium intensity) when it is the worse vs. the better option.
Within Participant Subjective Ratings of Acute Thermal Pain Following High Compared to Low Cues (Learned Via Conditioning)	Measured repeatedly during pain tasks, in each of the 10 sessions of the experiment (up to 3 sessions per week, depending on the participants' availability), immediately after thermal stimuli. Averaged across sessions and compared across conditions.	Each session of the experiment includes pain tasks, in which multiple thermal stimuli are delivered. Following each thermal stimulus, participants are asked to rate how painful it was, on a semi-circular computerized scale. Ratings are based on the angle (0-180), with higher angle representing higher pain ratings. In the conditioning procedure, cues are conditioned to different temperatures by delivering thermal stimuli with different temperatures after cues are presented (higher temperature following high cues and lower temperature following low cues). For the cues that were learned via conditioning, the investigators will compare the average rating of pain for stimuli that are preceded by high cues minus the average rating of pain for stimuli that are preceded by low cues (each averaged across sessions), within participant.
Within Participant Subjective Ratings of Acute Thermal Pain Following High Compared to Low Cues (Learned Via Symbolic Learning)	Measured repeatedly during pain tasks, in each of the 10 sessions of the experiment (up to 3 sessions per week, depending on the participants' availability), immediately after thermal stimuli. Averaged across sessions and compared across conditions.	Each session of the experiment includes pain tasks, in which multiple thermal stimuli are delivered. Following each thermal stimulus, participants are asked to rate how painful it was, on a semi-circular computerized scale. Ratings are based on the angle (0-180), with higher angle representing higher pain ratings. In the symbolic learning procedure, cues are conditioned to different temperatures based on pictures of thermometers (instead of actual thermal stimuli as in the conditioning procedure). For the cues that were learned via symbolic learning, the investigators will compare the average rating of pain for stimuli that are preceded by high cues minus the average rating of pain for stimuli that are preceded by low cues (each averaged across sessions), within participant.

Trial Locations

Locations (1)

Dartmouth College; 🇺🇸 Hanover, New Hampshire, United States