Sleep and memory consolidation in the elderly

The significance of sleep for memory consolidation has been investigated for several years. Even though aging affects both sleep and memory, only very few studies have addressed this topic in the context of aging so far. Recent findings with regard to sleep-related memory consolidation in old age suggest that processes of procedural memory consolidation during REM sleep as well as declarative memory consolidation during slow wave sleep are impaired in older adults. Posttraining increases in stage 2 sleep spindles also seem to be less pronounced in old age. Apart from age-related changes in sleep characteristics such as duration and microstructure of specific sleep stages, age-related changes at the neurochemical level, especially the cholinergic system, play an important role in this context. In addition, structural and functional changes of the brain with increasing age could adversely affect the efficiency of sleep-related memory consolidation in old age. In light of structural, functional and neurochemical changes of the brain with dementia as well as characteristic changes in sleep quality as part of the disorder, this patient group is of particular interest for the study of sleep-related memory consolidation in old age. The same applies to old age depression, which has not been studied systematically in this context so far.