<prompt> EEG rhythm recorded from the surface of the scalp during REM sleepa Alphab Betac Deltad Thetaabaadbc  <response>: Stages of sleep and rhythm- Beta rhythm- Alert, awake, maximum concentration.- Alpha rhythm- Eyes closed, mind wandering, less attentiveness- Theta rhythm- Stage 1 NREM- Sleep spindles, K complex- Stage 2 NREM- Delta rhythm- Deep sleep Stage 3 4 NREM - Beta Rhythm and occasional reappearance of alpha rhythm- REM 