Pain, Traumatic Memory
Conditions
Keywords
Pain, Traumatic Long-term Memory
Brief summary
Few studies have focused on understanding the mechanisms underlying pain memory in humans. Thus, this project aims to investigate the link between pain memorisation and memorisation of the associated context by addressing the issue of pain conditioning. The study is composed of two successive parts: one pilot then one experimental. The goal is to understand pain memorisation processes by analysing the parallel between pain memorisation and memorisation of a traumatic event. By using immersive virtual reality, investigators aim to show that contextual pain conditioning is associated with : 1- a specific neural networks; 2- a reactivation of vegetative and behavioural reactions related to pain as well as electro-physiological markers when re-exposure to the specific pain-conditioning-context; 3- an implicit hypermnesia of the pain-associated context and a struggle to extinguish conditioning; 4- a favoured elaboration of false memories of the contextual pain. The emitted hypothesis suggests that a cortical and behavioural mnemonic trace is created during encoding of pain in association with its context, and that the latter can reactivate although the pain itself has disappeared. This implicit cortical mnemonic trace, evoked by the simple pain-associated context, could explain the notion of pain print persisting at long-term in patients suffering from chronic pain.
Interventions
OTHERValidation of virtual environment and auditive stimulation with virtual reality glasses (Pilot phase)
The goal of this phase is the development of the experimental protocol in virtual reality. Virtual environment will be checked and auditive stimulation will be graduated.
OTHERElectrical cutaneous stimulation and auditive stimulation (Principal Experimental phase)
This phase is the principal step of the study: during moving in virtual environment, electrical stimulation on one hand and auditive stimulation will be applied. EEG, ECG and skin conductance will be measured during conditioning phase and extinction phase (day 1, 30 minutes each phase). Behavioral measures will be done throughout the 3 sessions (day 1, day 2 and day 30)
OTHERElectrical cutaneous stimulation and auditive stimulation (Secondary Experimental phase)
This phase is the same of the Principal Experimental phase except for the EEG that will not be performed.
Sponsors
Hospices Civils de Lyon
Study design
Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy subject * Subject between 18 and 50 years old * Subjects having given their written consent * Subjects with health insurance
Exclusion criteria
* Prior addiction to drugs * Prior neurological issues * Chronic pain (neuropathic or non-neuropathic) * Pregnant/breast-feeding women * Absence of efficient contraception method for the duration of the study (1 month) for participants of procreation age (no inclusion limitation for male participants of procreation age) * Subjects under chronic analgesic treatment or having taken an analgesic treatment in the 24 h preceding the experiment * Heart issues * Subjects under justice surveillance * Subjects participating in another study which inclusion period overlaps with the one from this study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Measurement of electrophysiological (EEG) changes during a pain conditioning set up and its extinction | day 1 | The EEG will be done throughout the conditioning phase and the extinction phase (30 minutes each)conducted during the first session of the experiment (Day 1) |
| Measurement of vegetative (electrodermal, electrocardiac) changes during a pain conditioning set up and its extinction | day 1 | The cutaneous response and electro-cardiographic activity will be done throughout the conditioning phase and the extinction phase (30 minutes each)conducted during the first session of the experiment (Day 1) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Assessment subject capacity to create false memory of environment according to the associated stimulation (pain or no pain) | day 2 | Questionnaire will be conducted on environment (presence or absence of different objects) to assess false memories |
| Assessment of short-term memory of an environment according to whether it is associated with a painful stimulation or not | day 2 | This outcome is evaluated by combined tests: * Free recall test: the subjects will have to quote a maximum of memorized objects during the conditioning phase * Recognition test: the objects present in the environment as well as objects not present in the environment will be presented randomly on a screen. Subjects should indicate whether the object in question was present in the environment or not. |
| Assessment of the total duration needed for total extinction | 30 minutes | The amount of time needed for vegetative reactions to go back to baseline will be assessed during the extinction phase |
| Eye-tracking measurements, to assess the exploration of different contexts according to their nature | Day 1 | An Eye-tracking system will be included in the Virtual Reality glasses (used during conditioning and extinction) to assess eye-movement during exploration of the environment |
| Assessment of long-term memory of an environment according to whether it is associated with a painful stimulation or not | day 30 | This outcome is evaluated by combined tests: * Free recall test: the subjects will have to quote a maximum of memorized objects during the conditioning phase * Recognition test: the objects present in the environment as well as objects not present in the environment will be presented randomly on a screen. Subjects should indicate whether the object in question was present in the environment or not. |
Countries
France
Contacts
Primary ContactLuis GARCIA-LARREA, MD
Backup ContactMaud FROT
Outcome results
None listed