| Abstract: | The effects of sleep fragmentation on behavioral control of sleeping respiration and on daytime sleepiness were investigated in 20 college students. All were polygraphically monitored both during nighttime sleep and during daytime naps. Ten experimental subjects were informed while awake that tones would be presented to them during nighttime sleep. Their task was to terminate the tones by taking a deep breath. Half of the subjects first received tones every 4 min; the other half received them every 8 min. After 4 consecutive nights subjects received 3 days off and conditions were reversed for 4 more consecutive nights. Tones started at 45dB and, in the absence of a response, increased 10dB every 10 seconds up to 95dB. Control subjects (N = 10) did not receive tones. The absolute number of arousals to tones was greater but the percentage of arousals was lower under the 4-min condition. Full awakenings occurred infrequently. Probability of making a breathing response remained high across days for both fragmentation conditions, but latency to respond was shorter and probability higher under the 8-min condition. Sleep fragmentation, whether “frequent” (4-min) or “infrequent” (8-min), did not induce greater daytime sleepiness than did the nonfragmentation control condition, and sleepiness did not differ between the two experimental conditions. Implications for developing behavioral techniques for treating sleep-related breathing disorders are discussed. |
