An interventional study of Medoc thermal stimulator and Electric shock stimulator in Normal Physiology, Healthy Volunteers and Pain, sponsored by National Center for Complementary and Integrative Health (NCCIH). Recruiting at 1 site in United States. Open to participants aged 18 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-20.
Sponsored by National Center for Complementary and Integrative Health (NCCIH) · Not applicable, Interventional, and Basic science
Objective
The current proposal investigates behavioral, psychophysiological, and social processes that may help explain biases and disparate outcomes in pain. Health disparities, or health outcomes that adversely affect disadvantaged populations, are pervasive and apparent in many diseases and symptoms, including pain. Pain is the number one reason individuals seek medical treatment. Health disparities in pain encompass both differences in pain experience and treatment for pain. For instance, research indicates that Black individuals report increased pain and have reduced pain tolerance relative to White individuals, yet doctors are less likely to treat minority patients pain and underestimate their pain experience. This project aims to address this systemic discrepancy by focusing on interpersonal processes that may contribute to these disparities, including socially-relevant responses to pain (i.e. pain expression) and pain assessment (e.g. visual attention). The proposed research aims to determine whether the study of pain expressions and their assessment can yield insights on how social factors shape pain and its treatment. Further, we test the efficacy of potential interventions designed to improve accuracy and reduce biases in pain assessment. If successful, this work will form the foundation of a new research program that will link the field of pain research with the field of social neuroscience, and forge new insights on the critical problem of health disparities in pain.
Study population
We will accrue up to 700 total healthy volunteers to target 325 completers
Design
Our overall aim is to understand how social factors influence the assessment and management of pain, and to gain insight into psychosocial processes that may underlie health disparities in pain. We propose a series of studies designed to test these links. First, we will measure pain perception and physiological responses to painful stimuli in a diverse group of individuals to test for sociocultural and biological influences on pain and pain-related responses. In subsequent studies, new participants ("perceivers") will view images of these initial participants ("targets") and will provide estimates of 'targets' pain experience. We will measure a) whether perceivers can accurately estimate 'targets' pain experience; b) whether accuracy differs as a function of similarity between target and perceiver (ingroup vs outgroup); and c) whether individuals can improve accuracy through feedback.
Outcome measures
Primary outcome measures for all experiments will be decisions about pain (experienced by self or other) measured with visual analogue scales, reaction time, and/or categorical judgments (pain/no pain). We will also measure physiological responses (e.g., facial muscle response, skin conductance, pupil dilation) and brain responses using functional magnetic resonance imaging (fMRI) as secondary outcome measures. We will test whether pain and pain-related responses varies as a function of sociocultural/demographic factors (e.g. race, ethnicity, sex) and whether accuracy in assessing others' pain is influenced by group similarity (i.e. ingroup vs. outgroup) and training (e.g. performance-related feedback)....
Objective
The current proposal investigates behavioral, psychophysiological, and social processes that may help explain biases and disparate outcomes in pain. Health disparities, or health outcomes that adversely affect disadvantaged populations, are pervasive and apparent in many diseases and symptoms, including pain. Pain is the number one reason individuals seek medical treatment. Health disparities in pain encompass both differences in pain experience and treatment for pain. For instance, research indicates that Black individuals report increased pain and have reduced pain tolerance relative to White individuals, yet doctors are less likely to treat minority patients' pain and underestimate their pain experience. This project aims to address this systemic discrepancy by focusing on interpersonal processes that may contribute to these disparities, including socially-relevant responses to pain (i.e. pain expression) and pain assessment (e.g. visual attention). The proposed research aims to determine whether the study of pain expressions and their assessment can yield insights on how social factors shape pain and its treatment. Further, we test the efficacy of potential interventions designed to improve accuracy and reduce biases in pain assessment. If successful, this work will form the foundation of a new research program that will link the field of pain research with the field of social neuroscience, and forge new insights on the critical problem of health disparities in pain.
Study population
We will accrue up to 700 total healthy volunteers to target 325 completers.
Design
Our overall aim is to understand how social factors influence the assessment and management of pain, and to gain insight into psychosocial processes that may underlie health disparities in pain. We propose a series of studies designed to test these links. First, we will measure pain perception and physiological responses to painful stimuli in a diverse group of individuals to test for sociocultural and biological influences on pain and pain-related responses. In subsequent studies, new participants ("perceivers") will view images of these initial participants ("targets") and will provide estimates of 'targets' pain experience. We will measure a) whether perceivers can accurately estimate 'targets' pain experience; b) whether accuracy differs as a function of similarity between target and perceiver (ingroup vs outgroup); and c) whether individuals can improve accuracy through feedback.
Outcome measures
Primary outcome measures for all experiments will be decisions about pain (experienced by self or other) measured with visual analogue scales, reaction time, and/or categorical judgments (pain/no pain). We will also measure physiological responses (e.g., facial muscle response, skin conductance, pupil dilation) and brain responses using functional magnetic resonance imaging (fMRI) as secondary outcome measures. We will test whether pain and pain-related responses varies as a function of sociocultural/demographic factors (e.g. race, ethnicity, sex) and whether accuracy in assessing others' pain is influenced by group similarity (i.e. ingroup vs. outgroup) and training (e.g. performance-related feedback).
10,054 studies on the registry are indexed under Pain; 1,649 are open to participants now.
This study's planned enrollment of 700 is above the median of 66 across 8,493 interventional studies indexed under Pain.
Browse Pain studies →National Center for Complementary and Integrative Health (NCCIH) is the lead sponsor of 223 studies on the registry; 7 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
All Sub-Studies:
EXCLUSION CRITERIA:
All Sub-Studies:
Sub-study 1:
Sub-study 4, FMRI participants:
Any FMRI , including:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Measuring facial response to painful stimulation.
Device: Medoc thermal stimulator · Device: Electric shock stimulator · Device: Cold water bath
Measuring pain assessment accuracy
Subjects will judge stimuli with the same instructions as Sub-Study 2 (which provides a test of replication).
Participants in substudy 3's Feedback Group will be informed about their performance after every trial when making judgments about other people's pain.
Behavioral: Pain assessment performance feedback
Heat pain stimulation for substudy 1
Electric pain stimulation for substudy 1
Cold pain stimulation for substudy 1
Participants in substudy 3's Feedback Group will be informed about their performance after every trial when making judgments about other people's pain.
Physiological responses (facial muscle movement, skin conductance, respiration, pupil dilation, eye gaze position)
We measure facial responses to painful stimuli in substudy 1 and eye position in substudy 2 and 3.
Time frame: Every visit
Pain perception (pain ratings)
Individuals report their perceived pain or the pain they associate with other people they are viewing.
Time frame: Every visit
Questionnaire measures (e.g. Fear of Pain questionnaire, McGill pain questionnaire)
We collect measures of identity and endorsement of beliefs about pain.
Time frame: Every visit
Plan to share: Yes — Deidentified data will be shared with other researchers as per the protocol. Identifiable data (i.e. images of faces) from participants who consent to data sharing may be shared with other researchers. Finally, identifiable data from participants who opt to be included in a stimulus set through the sub-study 1 consent form can be shown to other participants and in other studies to measure evaluation of facial responses to pain.
Supporting information: Informed consent form, Clinical study report, Analytic code
Time frame: Face stimuli are available following completion for viewing by other study participants. Deidentified data will be made available upon publication.
Access criteria: please see above.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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