Ironic effects of sleep urgency

Normal sleepers were instructed either to fall asleep as quickly as they could or to fall asleep whenever they desired, under a high mental load (listening to John Philip Sousa marches) or a low mental load (listening to sleep-conducive new age music). Under low load, participants trying to fall asleep quickly did so faster than those attempting only to fall asleep whenever they desired. Under high load, however, and consistent with the ironic process theory of mental control (Wegner, D. M., 1994, Psychological Review, 101, 34-52), sleep onset latency was greater for participants attempting to fall asleep quickly than for those not attempting to do so.