Healthy
Conditions
Brief summary
This study examines the effects of placebo suggestions tailored to match or mismatch individual participants' motivational styles-an issue of person-situation 'fit' with important effects in public health settings, but which has been ignored in past research.
Interventions
BEHAVIORALPlacebo cream- promotion suggestion
Over-the-counter hand cream will be applied to participants' skin, but they will be told that they are given a highly efficient topical analgesic cream. The suggestion will be based on a promotion approach (promoting good feelings).
BEHAVIORALPlacebo cream- prevention suggestion
Over-the-counter hand cream will be applied to participants' skin, but they will be told that they are given a highly efficient topical analgesic cream. The suggestion will be based on a prevention approach (preventing pain).
BEHAVIORALControl cream
In a control condition, with the same cream as in the placebo interventions, participants will be instructed that the cream is a control cream with no effects.
Sponsors
Trustees of Dartmouth College
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Masking description
Participants will not be aware of the type of suggestion (or the fact there are different types of suggestions) during the experiment. They will be debriefed upon the study's conclusion.
Intervention model description
This is a within-participant design. Each participant will participate in two sessions. In both sessions, an over-the-counter hand cream will be applied to their skin, accompanied by a placebo suggestion that the cream is analgesic. In one session, the suggestion will match the participant's motivational style, and in the other session the suggestion will not match their motivational style. The order of sessions will be counterbalanced across participants. Each session will also include a control condition, in which participants will be told that the cream has no affect. The same over-the-counter hand cream will be used in all sessions.
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy participants * Dominant promotion focus or dominant prevention focus (based on our screening)
Exclusion criteria
* Currently or recently suffered from chronic pain (based on screening) * Cannot tolerate heat pain applied to the forearm, based on a calibration task at the beginning of the experiment
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in subjective ratings of acute thermal pain | Measured repeatedly, immediately after thermal stimuli on the day of participation. Averaged and compared across interventions. | 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. We will average and compare the pain ratings within participant across interventions. |
| Changes in subjective ratings of pain expectations | Measured repeatedly, immediately before thermal stimuli on the day of participation. Averaged and compared across interventions. | Before each thermal stimulus, participants are asked to rate how painful they expect the next stimulus to be, on a semi-circular computerized scale. Ratings are based on the angle (0-180), with higher angle representing higher expectations ratings. We will average and compare the expectation ratings within participant across interventions. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Facial expressions | Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions. | We will obtain facial video recordings of participants with a video camera. We will analyze these data according to Facial Action Units (facial expressions) that are known to be related to pain, and compare them across interventions. |
| Thermal imaging of the face | Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions. | We will obtain thermal recordings of participant's face with an infrared camera, and compare the heat signature of the face (the temperature in different parts of the face) across interventions. |
| Changes in skin conductance response measured with a Biopac device | Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions. | Skin conductance will be measured. We will compare the skin conductance response to pain stimuli within participant across interventions. |
| Changes in heart rate measured with a Biopac device | Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions. | Heart rate will be measured. We will compare the heart rate in response to pain stimuli within participant across interventions. |
Countries
United States
Contacts
Primary ContactTor D Wager, PhD
Outcome results
None listed