There has been speculation that the REM cycle functions as a cyclic waxing and waning of instinctual drive activity. Some studies have been made of spontaneous diurnal oral activity cycles of energy discharge which are hypothetical counterparts to the rhythmic energy discharges occurring during REM cycles. The present study hypothesized that mild chronic schizophrenic patients, under conditions of relaxed semi-isolation, would show spontaneous, cyclic oral activity. The oral activities of seven patients were recorded and scored in consecutive 20-minute periods; the scores yielded cyclic data that supported the author's hypothesis.Abstract Teaser