Schlaf und Gedächtniskonsolidierung - Verlängerung

Ninety-six healthy subjects, age 18-30 will be trained with either a declarative memory task (paired-associate word list task according to Plihal & Born, 1997, adopted by Schabus et al., 2004) or a procedural motor learning task (mirror-tracing task according to Plihal & Born, 1997, adopted by Sauter et al., 2004) before taking a nap in the afternoon. For these specific tasks it has been shown that sleep generally enhances task performance when compared to the effects of corresponding retention intervals of wakefulness (Gais et al., 2000; Karni et al.; Plihal & Born 1997, 1999; Plihal et al. 1999; 1994; Sauter et al., 2004; Schabus et al., 2003, 2004; Stickgold et al., 1998, 2000a, 2000b). The primary goal for this study is to provide evidence for the effectiveness of napping on memory performance. As shown in our Project P 15 370 “Sleep and Memory Consolidation” night sleep enhances performance as well in an explicit as in an implicit memory task. Our new project aim is to study whether shorter sleep duration as given in a 90-minute nap opportunity in the afternoon is sufficient enough for memory consolidation in the same memory tasks. Napping would be a less cost and time consuming way to enhance performance than a whole night of sleep. If napping is as effective as one nights sleep this would have major implications on learning strategies during day. On the other hand a daytime nap would serve as a good experimental setting to test the 2-step model of memory consolidation, which states that NREM sleep is essential for explicit memory consolidation and REM sleep for implicit memory. Daytime naps tend to consist of mainly stage 2 sleep and our findings, that sleep spindle activity contributes to memory consolidation in an implicit word association task could be verified.