Periods of sleep manifested by changes in EEG activity and certain behavioral correlates; they formerly included Stage 1: sleep onset, drowsy sleep; Stage 2: light sleep; Stages 3 and 4: delta sleep, light sleep, deep sleep, telencephalic sleep. In 2007, sleep stages were redefined by The American Academy of Sleep Medicine (AASM) as: N1-N2 (sleep onset - light sleep), N3 (SLOW-WAVE SLEEP), and REM SLEEP
Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported