Differential Effects of Early and Late Nocturnal Sleep on the Consolidation of Declarative and Nondeclarative Memory

Differential Effects of Early and Late Nocturnal Sleep on the Consolidation of Declarative and Nondeclarative Memory Synopsis

Nocturnal sleep apparently promotes the translation of labile short-term memories into more stable long-term memories. The present studies suggest that the sleep-related consolidation of hippocampus-mediated memories benefits primarily from early nocturnal sleep. A reduced activation of hippocampal glucocorticoid receptors and a neocortico-hippocampal 'off-line' mode during this part of sleep may be of particular relevance for this phenomenon. In contrast, non hippocampus-mediated memories benefit primarily from late nocturnal sleep. In addition to a critical amount of REM sleep, other, yet unknown factors may contribute to the consolidation of non hippocampus-mediated memories during late nocturnal sleep.