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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
60
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).
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).
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.
Dartmouth College
Hanover, New Hampshire, United States
Changes in subjective ratings of acute thermal pain
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.
Time frame: Measured repeatedly, immediately after thermal stimuli on the day of participation. Averaged and compared across interventions.
Changes in subjective ratings of pain expectations
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.
Time frame: Measured repeatedly, immediately before thermal stimuli on the day of participation. Averaged and compared across interventions.
Facial expressions
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.
Time frame: Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.
Thermal imaging of the face
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.
Time frame: Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.
Changes in skin conductance response measured with a Biopac device
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Skin conductance will be measured. We will compare the skin conductance response to pain stimuli within participant across interventions.
Time frame: Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.
Changes in heart rate measured with a Biopac device
Heart rate will be measured. We will compare the heart rate in response to pain stimuli within participant across interventions.
Time frame: Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.