Meta-analyses demonstrate that sleep spindles, characterizing NREM sleep, may be a physiological index of high-level cognitive processes. The aim of the study is to determine if sleep spindles can predict interindividual variation in attention and cognitive performance. Relationship between attention and cognitive performance and sleep spindles characteristics (density, frequency and amplitude) recording during 1 night in 80 healthy subject (aged between 18-75y), will be calculated.

It is currently well demonstrated that sleep promotes brain plasticity and therefore is directly involved in cognitive processes such as memory, language, reasoning, learning, intelligence, problem solving…. Sleep deprivation affects most cognitive processes. More specifically, it is the sleep microstructure and in particular the sleep spindles that are specifically linked to memory, learning and cognitive abilities. Sleep spindles are grapho-elements that characterize NREM sleep. They exhibit high inter-individual stability and variability, depend on the genetic heritage and correlate with anatomical properties of the brain. Sleep spindles can therefore be considered as an electrophysiological "finger-print" as one of the most heritable traits of humans. Studies support the notion that sleep spindles are electrophysiological markers of high-level cognitive abilities. It remains to be seen whether the sleep spindles can predict interindividual variations in attention and executive functions.

Inclusion Criteria:

• Male or female subjects, aged 18 to 75,
• BMI between 18 and 27,
• Having no subjective daytime sleepiness (Epworth scale score ≤ 11),
• Subjects affiliated to a social security scheme,
• Subjects capable of understanding the study,
• Subjects available to come to the 2 visits required by the study,
• Having given written informed consent to participate in the study,
• Free, informed and written consent, dated and signed by the patient and the investigator before any examination required by the research,
• For simulated driving sub-study: Having a driving license (subsample).

Exclusion Criteria:

• Severe pathologies involving the short-term vital prognosis,
• Uncontrolled endocrine pathologies (dysthyroidism, diabetes),
• All progressive cardiovascular conditions,
• All progressive neurological conditions treated or not (brain tumor, epilepsy, migraine, stroke, sclerosis, myoclonus, chorea, neuropathy, muscular dystrophies, myotonic dystrophy ...),
• Current Psychiatric disorder: mood disorder (depression, bipolar disorder), anxiety disorder, psychosis
• Substance-related dependence,
• Shift workers or night workers who have been on call or on call in the last 72 hours,
• Psychotropic patients,
• Long-term treatment with benzodiazepines and z-drugs,
• Patients on cardiotropic,
• Deprived of liberty by a judicial or administrative decision,
• Pregnant or lactating woman,
• Subject under curatorship or tutorship.
• For simulated driving sub-study: Having simulator-sickness during the first practice session evaluated by Simulator Sickness Questionnaire (SSQ)