Interactions between memory structures and expectation effects - Mechanisms of pain processing

Interactions between memory structures and expectation effects - Mechanisms of pain processing - LCPA

Status

Recruiting

Phases

Unknown

Study type

Interventional

Source

DRKS

Registry ID

DRKS00033230

Enrollment

Registered

2023-12-20

Start date

2024-01-01

Completion date

Unknown

Last updated

2025-04-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Mechanisms of pain processing in healthy participants

Interventions

Group 1: Healthy participants receive thermal pain stimuli of low, medium and high intensity in two experimental blocks (within-subject design). It is investigated whether categorizing a visual stimul

Eligibility

Sex/Gender

All

Age

18 Years to 45 Years

Inclusion criteria

Inclusion criteria: none

Exclusion criteria

Exclusion criteria: -Body mass index 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

Design outcomes

Primary

Measure	Time frame
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.	—

Measure

Time frame

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.

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Secondary

Measure	Time frame
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.	—

Measure

Time frame

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.

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Countries

Germany

Contacts

Public ContactChristian Büchel

Institut für Systemische Neurowissenschaften, Universitätsklinikum Hamburg-Eppendorf

buechel@uke.de+49040741054726

Outcome results

None listed

Source: DRKS (via WHO ICTRP) · Data processed: Feb 4, 2026