 - Conventional polysomnography PSG. PSG will be performed during an entire night using Siesta, Compumedics equipment, recording two channels of the electroencephalogram, electrooculogram, electromyogram of chin muscles, hemoglobin saturation by pulse oximetry, oro-nasal flow by means of thermistor, thoracic and abdominal movements, electrocardiogram, anterior tibial electromyogram and body position. Sleep staging will be manual, following the classical criteria of Rechschaffen Kales. The minimum recording time will be 6 hours, and the total time of minimal sleep will be 3 hours. 