Motor Performance Is not Enhanced by Daytime Naps in Older Adults

Abstract

The impact of sleep on motor learning in the aging brain was investigated using an experimental diurnal nap setup. As the brain ages several components of learning as well as motor performance change. In addition, aging is also related to sleep architectural changes. This combination of slowed learning processes and impaired sleep behavior raises the question of whether sleep can enhance learning and specifically performance of procedural tasks in healthy, older adults. Previous research was able to show sleep-dependent consolidation overnight for numerous tasks in young adults. Some of these study findings can also be replicated for older adults. This study aims to clarify whether sleep-dependent consolidation can also be found during shorter periods of diurnal sleep. The impact of midday naps on motor consolidation was analyzed by comparing procedural learning using a sequence and a motor adaptation task, in a crossover fashion in healthy, non-sleep deprived, older adults randomly subjected to wake (45 min), short nap (10–20 min sleep) or long nap (50–70 min sleep) conditions. Older adults exhibited learning gains, these were not found to be sleep-dependent in either task. The results suggest that daytime naps do not have an impact on performance and motor learning in an aging population.

The Effects of an Afternoon Nap on Episodic Memory in Young and Older Adults

“…There are a few existing memory consolidation, sleep, and aging studies that have used napping paradigms, but these studies focused on procedural, or motor, memory consolidation. [56][57][58][59] The important point here is that whereas most research has indicated an age-related change in sleep-dependent procedural memory consolidation, 60 some researchers have reported that episodic memory consolidation is preserved in older adults. 61 The current evidence compels the conclusion that sleep intervals will not always benefit episodic memory consolidation in older adults, even when using methods that aim to minimize age deficits at encoding and retrieval.…”

Can Daytime Napping Assist the Process of Skills Acquisition After Stroke?

“…Date of stroke and stroke-affected brain regions were extracted from medical records or determined from magnetic resonance imaging. The comparison group of 30 healthy older adults, previously described elsewhere ( 35 ) participated in an identical experimental setup. The study was approved by the local ethics committee (“Ethik-Kommission der Ärztekammer Hamburg,” Germany, PV4596) in accordance with the declaration of Helsinki ( 41 ).…”

“…The study design and the adaptation task was identical to previously published studies in younger and older adults ( 35 , 42 ). In brief, this included three successive learning sessions taking place at the University Sleep Medical Center Hamburg (Figure 2 ).…”

“…The task integrated visual feedback, visual motor perturbation and equivalent motor planning ( 34 ), and was performed with the affected hand, i.e., the hand which is controlled by the lesioned hemisphere. In a secondary analysis, the observed performance changes in stroke survivors were compared with those of a previously studied group of healthy adults ( 35 ).…”

Adult Gross Motor Learning and Sleep: Is There a Mutual Benefit?

“…For example, postsleep consolidation in older adults was found to be dependent on the movement kinematic [ 87 ]: while a finger sequence task failed to show sleep-related gains, a kinematically adapted gross motor whole-hand task showed sleep-dependent consolidation. In addition, studies using less complex tasks such as finger sequences [ 88 ] and mirror tracking [ 89 ] also reported lack of sleep-dependent consolidation (for a review, see also [ 90 ]). The majority of the studies on GML have focused on sleep-induced performance gains in young adults.…”