Epilepsy, Memory Consolidation
Conditions
Keywords
Epilepsy, Memory consolidation, Sleep, Reharsal, Reactivation
Brief summary
Memory consolidation transforms unstable memory traces into lasting representations, a process enhanced by both sleep and rehearsal during learning. Rehearsal is thought to accelerate consolidation by inducing memory reactivations that resemble those occurring during sleep. However, the respective mechanisms of sleep- and rehearsal-induced consolidation-and their potential interactions-remain poorly understood, especially in patients with temporal lobe epilepsy, where rehearsal might help compensate for memory deficits linked to hippocampal dysfunction, and where sleep may exacerbate epileptic activity. The CORESOM-EPI study aims to compare the effects of rehearsal and sleep on memory consolidation in patients undergoing video-EEG monitoring. Participants will learn object-place associations under two conditions (single versus repeated encoding), with memory tested immediately and again after a 12-hour delay. This delay will either include a full day awake or a night of sleep, allowing direct comparison of sleep- and rehearsal-related consolidation effects. Each participant will perform the task twice, with wake and sleep condition, in a balanced order. As a preliminary phase of the CRIMES study (ANR-DFG 2024), CORESOM-EPI will help assess how sleep and rehearsal influence memory consolidation in epilepsy. It will also serve to adapt the behavioral task for clinical use, paving the way for a future intracranial EEG investigations that will explore the neural networks involved and their modulation by epileptic activity.
Interventions
OTHERCognitive memory task on a computer
Encoding: (1) Participants will learn 60 associations between pairs of items (cue and target) that are presented sequentially at unique locations on a screen, in a given context. 30 pairs are presented once, and 30 pairs are presented repeatedly (4 times). (2) After learning, the first recall phase begins after a short delay of 30 minutes: 50% of the pairs are tested in a similar way, this time with an assessment of contextual memory. (3) The remaining 50% of pairs are tested after a 12-hour delay, involving either a day awake (condition 1) or a night asleep (condition 2).
OTHEREye tracking
Eye-tracking will be carried out during the task to ensure that participants are focused on the task (quantification of the number and duration of eye fixations in the area of interest corresponding to the target presentation)
OTHERQuestionnaires on task-related fatigue
Questionnaire on task-related fatigue (Likert-scale) will be completed by participants between blocks of items during the task
OTHERQuestionnaire on task difficulty
Questionnaires on task difficulty (Likert-scale) will be completed by participants at the end of the task
OTHERKarolinska scale
Participants' state of sleepiness will be assessed at the beginning of each stage (encoding, immediate recall, delayed recall) using the Karolinska sleepiness scale
Sponsors
Hospices Civils de Lyon
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Patient with epilepsy (any type of epilepsy) * Hospitalized for video-EEG recording lasting at least 4 days * Aged 18-65 years
Exclusion criteria
* Major cognitive impairment other than memory deficit * Refusal to participate * Pregnant women, women in labor or nursing mothers * Persons deprived of their liberty by judicial or administrative decision * Persons under psychiatric care * Persons admitted to a health or social institution for purposes other than research * Adults under legal protection (guardianship, curatorship)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in the percentage of object categories recalled (vs. not recalled) between immediate (30 min after learning) and delayed (12h after learning) recall for rehearsed versus non-rehearsed items. | Day 2 | The impact of rehearsal on object category recognition in an object-place learning paradigm is assessed. For the primary outcome, data from the 2 conditions (wake and sleep during the 12h period between immediate and delayed recall) will be pooled. Each participant will take part in the wake and sleep condition over 4 days (2 conditions separated by at least 24h), in a balanced order between participants. |
Countries
France
Contacts
Primary ContactLaure PETER-DEREX, Professor
Backup ContactSylvain Rheims, Professor
Outcome results
None listed