Interactions between memory structures and expectation effects - Mechanisms of pain processing
Not Applicable
Recruiting
- Conditions
- Mechanisms of pain processing in healthy participants
- Registration Number
- DRKS00033230
- Lead Sponsor
- Institut für Systemische Neurowissenschaften, Universitätsklinikum Hamburg-Eppendorf
- Brief Summary
Not available
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Recruiting
- Sex
- All
- Target Recruitment
- 50
Inclusion Criteria
none
Exclusion Criteria
-Body mass index <18 or >30
-Presence of acute or chronic somatic or psychiatric illnesses (based on self-report or routine examination)
-Presence of MRI-specific exclusion criteria (claustrophobia, pacemakers, non-MRI compatible metallic foreign bodies)
-Participation in other studies involving medication, or regular medication intake (except thyroid, allergy medication, occasional use of pain medication)
-Intake of pain medication within 24 hours prior to start of examination
-Pregnancy or breastfeeding
-Acute skin disease or injury at the sites to be stimulated
Study & Design
- Study Type
- interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method The present study aims to investigate whether categorizing a new painful stimulus into a previously experienced category manipulates pain expectation and consequently acute pain perception in healthy participants. The primary endpoint of this study is the subjectively rated pain intensity of thermal stimuli as well as the associated activity in pain-processing brain areas. These endpoints should reflect the inferred latent cause”: In the placebo condition, in which a categorization into a lower pain state occurs, we expect reduced pain ratings accompanied by reduced activity in pain-processing-related brain areas. In the nocebo condition with an inferred higher pain state, we expect increased ratings and activity accordingly.
- Secondary Outcome Measures
Name Time Method Secondary endpoints are the multivariate representation of the mixed stimulus, which should show greater similarity to the respective original stimulus in the orbitofrontal cortex given an inferred common state, as well as stronger decoding of the mixed stimulus in the fusiform face area or parahippocampal place area, depending on the inferred state. Moreover, we expect hippocampal activity to reflect the creation of a new inferred state. Additionally, we will use mathematical models, specifically the 'Latent Cause' model from Gershman et. al, to better explain the cognitive mechanisms behind the categorization into states and the subsequent pain ratings of the participants.