Sleep protects memories from interference in older adults

Abstract

In a recent study, we demonstrated that sleep-dependent consolidation of declarative memories is preserved in older adults. The present study examined whether this benefit of sleep for declarative learning in older adults reflects a passive role of sleep in protecting memories from decay or an active role in stabilizing them. Young and older adults learned a visuo-spatial task and recall was probed following sleep or wake. Although a reduction in performance was observed following sleep and wake, task-related interference prior to recall had a larger detriment on performance in the wake condition. This was true for young and high performing older adults only. Low performing older adults did not receive a benefit of sleep on the visuo-spatial task. Performance changes were associated with early night NREM sleep in young adults and with early night REM sleep in high performing older adults. These results demonstrate that performance benefits from sleep in older adults as a result of an active memory stabilization process; importantly, the extent of this benefit of sleep is closely linked to the level of initial acquisition of the episodic information in older adults.

Emotional bias of sleep-dependent processing shifts from negative to positive with aging

“…This approach is relevant for studies comparing older and young adults given that the distribution of sleep stages across the night changes with age (Lombardo et al, 1998; Sonni and Spencer, 2015). Quartiles (total sleep time divided by 4) were chosen as the unit of division due to their near correspondence to sleep cycle length (Sonni and Spencer, 2015) and to allow for comparison with past studies. Emotional processing may occur primarily during the second half of the night when REM sleep is more abundant and cortisol levels are rising.…”

Mild Traumatic Brain Injury Chronically Impairs Sleep- and Wake-Dependent Emotional Processing

“…63 That is, sleep-dependent consolidation is optimized when both non-REM and REM are present and also sequential. [64][65][66] The delay in REM onset and general reduction in REM in this sample may have hindered consolidation by reducing such REM/non-REM interactions. Relatedly, it has long been proposed that amygdala activation during REM is critical for sleep-dependent emotional processing.…”

Hippocampal activity mediates the relationship between circadian activity rhythms and memory in older adults

“…Research has begun to link changes in sleep and cognition by suggesting that co-occurring sleep problems may uniquely contribute to cognitive deficits. Negative correlations have been observed in older adults between cognitive performance and disrupted sleep on tests of global cognitive impairment (Jelicic et al, 2002;Blackwell et al, 2006;Carvalho-Bos et al, 2007), working memory (Haimov et al, 2008;Nebes et al, 2009;Lim et al, 2012), mental speed (Oosterman et al, 2009), memory encoding (Mander et al, 2013a), memory retrieval (Westerberg et al, 2010), and memory consolidation (Wilson et al, 2012;Mander et al, 2013b;Sonni and Spencer, 2015).…”