THE USE OF PROPHYLACTIC NAPS AND CAFFEINE TO MAINTAIN PERFORMANCE DURING A CONTINUOUS OPERATION

After a normal baseline night of sleep and a morning of baseline test performance, 24 young adult male subjects returned to bed from 16:00-2 0:00 prior to a 24 h period of sleep loss. Twelve subjects received ca ffeine 200 mg at 01:30 and 07:30. Performance tests (correctly complet ed addition problems, vigilance sensitivity, and logical reasoning cor rect responses) all indicated maintenance of baseline performance leve ls in the caffeine group after administration of caffeine while perfor mance declined in the placebo group. Similar results were found for th e Multiple Sleep Latency Test and Oral Temperature, which both remaine d near baseline levels throughout the observation period in subjects r eceiving caffeine. The results indicated that the combination of a pro phylactic nap and caffeine was more effective in maintaining nocturnal alertness and performance than was the nap alone. Of more interest wa s the fact that the group which was given the combination of nap and c affeine was able to maintain alertness and performance at very close t o baseline levels throughout a 24 h period without sleep.