Alpha rhythm in EEG is seen in
The EEG recordings show typical features of sleep which is broadly divided into two broadly different phases: 1. D-sleep (desynchronised or dreaming sleep), also called as REM- sleep (rapid eye movement sleep), active sleep, or paradoxical sleep. 2. S-sleep (synchronised sleep), also called as NREM-sleep (non-REM sleep), quiet sleep, or ohodox sleep. S-sleep or NREM-sleep is fuher divided into four stages, ranging from stages 1 to 4. As the person falls asleep, the person first passes through these stages of NREM-sleep. The EEG recording during the waking state shows alpha waves of 8-12 cycles/sec. frequency. The onset of sleep is characterised by a disappearance of the alpha-activity. Ref: A Sho Textbook of Psychiatry, Niraj Ahuja, 7th Edition, pg. no. 133
Sleep with eyes closed and mind wandering
Mental activity
Awake with eyes open
REM sleep
Sleep disorders and eating disorders