Eligibility Criteria:
Inclusion Criteria:
* 20-25-year-old healthy Volunteers or of 40-50 years, male, Caucasian,
* Presenting no disorder of the perception,
* Taking no treatment interfering with the sleep, the attentiveness and the circadian system,
* BMI ≥18 et ≤ 27
* Moderate Drinker of coffee(café) (2-3 cups a day) •
* Presenting no medical history or evolutionary pathology,
* Not presenting syndrome of apneas / hypopnea during the sleep (IAH \< 5 for 20-25 years and 10 for 40-50 years),
* Not presenting syndrome of periodic movements during the sleep (Index of MPS \< 15),
* Not professional Driver, having their driving license for at least 3 years or 2 years for the drivers who followed the learning anticipated and driving between 10000 and 20000 km a year,
* Having looked in writing their consent to participate in the study,
* Having regular schedules of life 3 days before going into the study,
* Registers on the Social Security and on the register of the healthy volunteers.
Exclusion Criteria:
* Night workers,
* Any evolutionary psychiatric affections (psychosis, disorder(confusion) of the mood or the anxiety),
* All the sleeping disorders (sleep apneas, periodic leg movements, narcolepsy, phase delay, advance of phase),
* Any evolutionary neurological affections (brain tumour, epilepsy, Headache, brain vascular accident, calcifies, myoclonia , chorea, neuropathy, muscular dystrophies, myotonic dystrophy),
* Cardiovascular Pathologies (arterial high blood pressure, cardiac insufficiency, coronary disease, vascular disorders(confusions)),
* Lung Pathologies (BPCO, BPR),
* Renal Disorders(Confusions) (renal insufficiency, nephrolithiases),
* Endocrine Pathologies (dysthyroid, diabetes),
* Drug addiction, alcoholic dependence during the last 6 months,
* Having made a trans-meridian journey (± 3 hours) in last 3 months.