<prompt> In EEG, delta waves are seen:Due to reticular systemWhen the thalamus is cut off from ponsIn deep sleep TypeThese originate from thalamocortical area  <response>: Ans. C. In deep sleep Type Frequency HzLocationNormallyPathologicallyDeltaup to 3frontal, high amplitude 20- 200uVAdultsdeep sleep infants subcortical lesions diffuse lesionsTheta4-7 HzParietal and temporal regions young childrendrowsiness early sleep focal subcortical lesionsAlpha8 -12 HzParietal and occipital 50- 100 uV closing the eyes and by relaxation.Frequency decreases in: hypoglycemia, hypothermia, hypercapnia, GA, sleep, comaBeta12 - 30 HzFrontal region; low amplitude waves 10 uV active, busy or anxious thinking, active concentration sedatives 