ABSTRACTSubjects were instructed to attempt identification of feeling states which would keep on a blue light operated by EEG alpha activity. A closed physiologic feedback system was used and no stimuli external to the circuit were employed. A highly significant degree of enhanced alpha activity was achieved in the first practice session, and 60% of the subjects showedspecificityof the response to the light signal situation as compared to the same situation without the light signal. Greatest achievement of enhanced alpha activity appeared to be related to narrowing of perceptual awareness and pleasant feeling states.