.Beta: high-amplitude waves seen in deep alpha sleep and when reticular activating system is damped be eta strongest from frontal lobes near precentral gyrus *wwMwwwr Produced by theta visual stimuli and mental activity Evoked activity delta 13 cycles/sec 1 second interval (b)•Beta:high-amplitude waves seen in deep sleep and when reticular activating system is damped –Strongest from frontal lobes near precentral gyrus. •Produced by visual stimuli and mental activity. •Evoked activity. –13-25 cycles/sec