Slow Waves During Sleep and Wakefulness: a Common Denominator for Cognitive and Attentional Disorders in Normal and Pathological Aging (Exploratory Study)
With age, memory processes (encoding, consolidation and retrieval) as well as daytime vigilance are altered. Sleep is also impaired in older adults, notably slow waves that are known to play a key role in memory consolidation. Interestingly, some slow waves can also be detected in EEG recordings during wakefulness, and have been related to vigilance fluctuations. The investigators believe that slow waves, during both sleep and wakefulness, could constitute a common biomarker of sleep disturbances and daytime vigilance problems. A dysregulation of slow waves could thus explain the impact of aging on the different memory processes. Since alterations in memory capacity, attention, and sleep quality are further exacerbated in patients with Alzheimer's disease (AD), the investigators propose to study the links between aging (normal and pathological), sleep and daytime vigilance alterations, and their impacts on the different key stages of memory. The investigators will examine the associations between slow waves and changes in memory and vigilance in normal and pathological aging by studying young adults, seniors without cognitive disorders, and patients with prodromal AD. By replaying sensory cues associated with learning material during sleep, the investigators will also evaluate the effectiveness of auditory stimulation during sleep to enhance memory consolidation in older adults without and without cognitive deficits. Overall, this study aims to better understand the relationships between slow waves, aging, memory, and vigilance, providing insights into cognitive decline and potential interventions in aging and Alzheimer's disease.
• Patients:
• Age: 60 to 85 years Prodromal stage of Alzheimer's disease diagnosed according to international diagnostic criteria, characterized by a clinical phenotype of progressive amnesic syndrome of the hippocampal type, associated with biological markers of Alzheimer's disease from lumbar puncture (Aβ \< 600 pg/mL and ptau \> 60 pg/mL)
• Cognitively Healthy Seniors:
• Age: 60 to 85 years Age and sex matched with the Patients group Cognitively healthy status defined by a score of ≥ 26 on the MMSE (Mini-Mental State Examination), a score of ≥ 16 on the BREF (Batterie Rapide d'Efficience Frontale), and a score of ≥ 8 on the 5-word test
• Young Adults:
• Age: 18 to 35 years Sex matched with the Patients group Cognitively healthy status defined by a score of ≥ 26 on the MMSE (Mini-Mental State Examination), a score of ≥ 16 on the BREF (Batterie Rapide d'Efficience Frontale), and a score of ≥ 8 on the 5-word test