Neural and Psychological Mechanisms of Pain Perception
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-50
SponsorNational Center for Complementary and Integrative Health (NCCIH)
About this trial
Background:
\- Painful stimuli cause changes in a network of brain regions called the "Pain Matrix." But most of these regions respond to many other stimuli, not just pain. Researchers want to understand how different factors influence pain. They want to test what happens when people expect different levels of pain and receive treatments that can modify pain. They want to see if these factors influence decisions about pain and how the body responds to it. They also want to compare pain with responses like taste and vision.
Objectives:
\- To better understand how pain and emotions are processed and influenced by psychological factors.
Eligibility:
\- Healthy volunteers ages 18-50.
Design:
* This study requires 1 to 2 clinic visits that last 1 to 3 hours. * Participants will be screened with medical history and physical exam. * Some participants will have one or more magnetic resonance imaging (MRI) scans of their brain. For MRI, participants will lie on a table that slides in and out of a cylinder. The scanner makes loud knocking noises. They will get earplugs. * Participants' heart activity will be recorded with electrocardiogram. Their pulse, sweating, and breathing will be monitored. * Some participants will take a taste test. Others may perform simple tasks. Others may receive pain in their arm, leg, or hand. The pain will come from heat or electric shocks. Others may judge pain using a topical pain-relieving cream. Some of these tests may be given during MRI. * Participants will fill out questionnaires. * The study will last 3 years.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Healthy
Between 18 and 50 years old
Fluent in English
Able to provide written informed consent.
Disqualifiers
Unable to comply with study procedures or follow-up visits.
Has a major medical condition or medical history that in a clinician's assessment could affect heat sensitivity, pain thresholds, or ability to comply with study procedures. This may include cardiovascular, autonomic, or neurological conditions, including stroke, blindness, deafness, a history of brain damage, or a chronic systemic disease (e.g., diabetes).
Has a current mood disorder, anxiety disorder, or substance use disorder, or has a history of psychosis, hospitalization for a mental health condition, or recurrent psychiatric episodes.
Has a medical condition that in a clinician's assessment might affect somatosensation (e.g., Raynaud's disease, peripheral neuropathy, or circulatory disorder).
Trial design
Design model
Parallel
Treatments tested in this trial
Instructions
BehavioralIn sub-study 1, half the participants are instructed about outcomes, half learn through experience.
Attention
BehavioralIn sub-study 4, participants learn about outcomes and we manipulate attention toward or away from the pain.
Thermal Pain
BehavioralIn sub-studies 2 and 3, participants are exposed to thermal stimuli and/or tastants (sugar water, salt water, neutral rinse) and we are measuring how learning varies based on the type of outcome.
Placebo instructions
BehavioralIn sub-study 5, we test whether placebo effects and expectancy cues modulate pain through similar mechanisms.
Treatment groups
550 Participants
are divided into 8 treatment groups8
Treatment groupsSee each treatment group below.
Group A: Substudy 1: Instructed subjectsOther 1 intervention
Group B: Substudy 1: Uninstructed subjectsOther 1 intervention
Group C: Substudy 2: heat groupOther 1 intervention
Group D: Substudy 2: salt groupOther 1 intervention
Group E: Substudy 2: sugar groupOther 1 intervention
Group F: Substudy 3: healthy volunteersNo intervention 0 interventions
Group G: Substudy 4: healthy volunteersOther 1 intervention
Group H: Substudy 5: healthy volunteersOther 1 intervention
Trial outcomes
Primary outcomes
1
Physiological responses (heart rate, skin conductance, respiration, pupil dilation, eye gaze position)
In behavioral and fMRI experiments, we measure autonomic responses in anticipation and response to painful and non-painful stimuli using non-invasive measures.
Time frame
During the study visit in response to painful and non-painful stimuli.2
Pain perception (pain ratings)
Substudies of pain collect pain ratings using a visual analogue scale, either verbally or via computer.
Time frame
During the study visit in response to painful stimuli.3
BOLD response in brain regions of interest measured using fMRI
FMRI substudies proceed following behavioral substudies. We measure brain responses in anticipation and response to painful and non-painful stimuli.
Time frame
During the study visit in response to painful and non-painful stimuli.Secondary outcomes
1
Questionnaire measures (e.g. State-trait anxiety index, Fear of Pain questionnaire, Intolerance of Uncertainty questionnaire, McGill Pain Questionnaire)
Personality measures that have been linked with pain and emotion will be tested as moderators of effects on the above outcomes.
Time frame
Trait measures are collected during initial screening visit ; State measures are collected on every visitSponsors and contacts
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Source ClinicalTrials.gov