The significance of non-REM sleep for memory processes in elderly subjects

Various studies described a multifaceted relationship between sleep and memory. However not much is known about how the different sleep stages contribute to memory consolidation. So far studies point to a connection of NREM-sleep and declarative learning as opposed to an association between procedural learning and REM-sleep. In an ongoing study among others the effect of non-REM2 sleep on learning processes is analysed. In the study night the percentage of REM- and non-REM-sleep is experimentally influenced. Participants perform a procedural and a declarative learning task in the evening before and in the morning after the study night. Preliminary results indicate a strong correlation between the amount of non-REM-sleep (sleep stage 2) and the declarative learning performance (r=.726; p< .001). Confirming the data found in younger subjects, our study seems to indicate that there is a strong connection between declarative learning tasks and non-REM-sleep also in older subjects.