Abstract Mkid 190

The sleep enhancing effect on memory (sleep-memory-effect) is well documented for night-time sleep as well as for midday naps. Several reasons may account for this effect. One may be a diminished interference during sleep which may support an undisturbed memory consolidation. To test this hypothesis, memory performance was compared after a midday nap, after relaxation-hypnosis, inducing also a state of low interference, and after wakefulness. Subjects had to perform a declarative memory task (word-list learning) and a procedural memory task (mirror-tracing). Results indicate that declarative memory was better following the midday naps or relaxation-hypnosis compared to wakefulness, respectively. No differences were observed between both low interference conditions (sleeping, hypnosis). Procedural memory was not affected by the kind of treatment. The results support the interference-hypothesis for declarative memory, indicating, that a state of reduced interfering mental activity may account for the sleep-memory-effect.