EEG waves prominent in occipital lobe is
Stages of Sleep Electrophysiological Criteria Stage Of Sleep 1)Voltage 2) Frequency 1)EOG 2)EMG Wakefulness (eyes closed) 1)Low-voltage2) mixed, Alpha (8-13 Hz) 1)Eye movements, blinks2)High tonic activity, voluntary movements Non Rapid Eye Movement sleep 75 %* Stage I 5 % 1)Low-voltage, 2) mixed, Theta (3-7 Hz)*, veex sharp waves 1)Slow eye movements2)Tonic activity slightly decreased stage II 45 % 1)Low-voltage2) mixed ,K-complexes* sleep spindles * (12-14 Hz bursts) 1) Low tonic activity 2)EOG None Stage III 12 % 1)High-amplitude (75 uV) 2) Slow(delta) waves * (< 2Hz) occupying 20% to 50 % of epoch Stage IV 13% 1)High-amplitude 2) Slow(delta) waves occupy >50% of epoch Rapid Eye Movements sleep 25%* 1)Low-voltage2) Mixed, Saw-tooth waves, theta activity, slow alpha activity 1)Tonic atonia* with phasic twitches 2)Rapid Eye Movements As we proceed from wakefulness to sleep, we see the EEG waves becoming slower (i.e decreasing in frequency), increasing in amplitude, heterogeneous (mixed activity) to homogenous waves. K complexes (negative sharp wave followed by a positive slow wave) EEG wave Frequency Recorded B A Te D Beta 13-30 Hz Parietally, frontally Activation of various areas of the brain Alpha 8-13 Hz Occipitally Wakefulness(eyes closed) Theta 4-8 Hz All areas Sleeping adults, children Delta 0.5-4Hz All areas Sleeping adults, infants Pneumonic BATeD waves in active brain - deep sleep Reference: P.752 24.1 Normal Sleep Kaplan & Sadock's Synopsis of Psychiatry: Behavioral Sciences/Clinical Psychiatry, 10th Edition)
Alpha
Beta
Gamma
Theta
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