Sleep and Rehearsal-Driven Memory in Epilepsy

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.

Conditions

• Epilepsy
• Memory Consolidation

Interventions

OTHER

Cognitive 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).

OTHER

Eye 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)

OTHER

Questionnaires on task-related fatigue

Questionnaire on task-related fatigue (Likert-scale) will be completed by participants between blocks of items during the task

OTHER

Questionnaire on task difficulty

Questionnaires on task difficulty (Likert-scale) will be completed by participants at the end of the task

OTHER

Karolinska 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 & Collaborators

• Hospices Civils de Lyon

  lead OTHER

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-06-30

Primary Completion

2026-07-31

Completion

2026-07-31

Countries

• France

Study Locations