The research proposed here uses a behavioral approach to deal with sleep related breathing disorders such as sleep apnea - hypopnea syndromes and chronic obstructive pulmonary disease. Procedures for acquiring effective behavioral control over sleeping respiration have been developed in normal, healthy subjects. A high degree of control was acquired in these subjects with only minimal disruptions of their sleep. The present experiments are intended to refine the technique and to evaluate whether the behavioral control procedures developed with healthy, normal subjects can be applied clinically to patients suffering from sleep related breathing disorders. Six experiments are described. Two are laboratory experiments using healthy, normal participants. The two laboratory experiments will aid in refining the method and in evaluating the effects of nocturnal awakenings on the quality and restorativeness of sleep. The other four experiments deal directly with different patient populations who have been diagnosed in a sleep disorders center (polysomnography) has having sleep related breathing disorders. This research will take place at a sleep disorders center. One experiment tests the behavioral technique with patients diagnosed as having chronic obstructive pulmonary disease. An effort will be made to increase their ventilatory effort and to avoid the severe episodes of hypoxemia that occurs with these patients during sleep. With one procedure an attempt will be made to prevent hypoxemic episodes from occurring; with the other an attempt will be made to restore oxygen saturation levels once they begin to occur. A second experiment tests patients diagnosed as having sleep apnea syndrome and hypopneas with attendant instances of severe oxygen desaturation. We will test the extent to which apnea and hypopnea periods can be reduced and whether hypoxemia can be avoided. A third experiment assesses whether long term (21 days) behavioral control of sleeping respiration is possible using COPD and apnea/hypopnea patients. The last experiment assesses the feasibility of developing a device for aiding the control of respiration at home.