ABSTRACT
Sustaining performance across extended periods of time requires the maintenance of both physical and mental efficiency in the face of conditions that would normally lead to their impairment. The most robust evidence of sleep-dependent memory consolidation in humans comes from studies of procedural skill learning. Deterioration over time is generally greater across periods of wake than across periods including sleep, and appears to depend on periods of Slow Wave Sleep (SWS) and sleep appears to make such memories more resistant to subsequent interference. As with the visual texture discrimination task, improvement can be seen more rapidly with daytime naps. Subjects who succeeded in obtaining both SWS and rapid-eye-movement in a 60 or 90 minutes afternoon nap opportunity showed as much improvement when tested several hours later as did subjects allowed a full night of sleep. As might be expected, sleep deprivation prior to training on a declarative memory task leads to impaired retention of memories.
