Short Nap Research Articles

Melatonin Secretion during a Short Nap Fosters Subsequent Feedback Learning.

Sleep helps to protect and renew hippocampus-dependent declarative learning. Less is known about forms of learning that mainly engage the dopaminergic reward system. Animal studies showed that exogenous melatonin modulates the responses of the dopaminergic reward system and acts as a neuroprotectant promoting memory. In humans, melatonin is mainly secreted in darkness during evening hours supporting sleep. In this study, we investigate the effects of a short period of daytime sleep (nap) and endogenous melatonin on reward learning. Twenty-seven healthy, adult students took part in an experiment, either taking a 90-min afternoon nap or watching videos (within-subject design). Before and after the sleep vs. wake interval, saliva melatonin levels and reward learning were measured, and in the nap condition, a polysomnogram was obtained. Reward learning was assessed using a two-alternative probabilistic reinforcement-learning task. Sleep itself and subjective arousal or valence had no significant effects on reward learning. However, this study showed for the first time that an afternoon nap can elicit a small but significant melatonin response in about 41% of the participants and that the magnitude of the melatonin response predicts subsequent reward learning. Only in melatonin responders did a short nap improve reward learning. The difference between melatonin-responders and non-responders occurred very early during learning indicating that melatonin might have improved working memory rather than reward learning. Future studies should use paradigms differentiating working memory and reward learning to clarify which aspect of human feedback learning might profit from melatonin.

Using relaxation techniques to improve sleep during naps.

Insufficient sleep is a common occurrence in occupational settings (e.g. doctors, drivers, soldiers). The resulting sleep debt can lead to daytime sleepiness, fatigue, mood disorder, and cognitive deficits as well as altered vascular, immune and inflammatory responses. Short daytime naps have been shown to be effective at counteracting negative outcomes related to sleep debt with positive effects on daytime sleepiness and performance after a normal or restricted night of sleep in laboratory settings. However, the environmental settings in the workplace and the emotional state of workers are generally not conducive to beneficial effects. Here, we tested whether relaxation techniques (RT) involving hypnosis might increase total sleep time (TST) and/or deepen sleep. In this study, eleven volunteers (aged 37–52) took six early-afternoon naps (30 min) in their occupational workplace, under two different conditions: control ‘Naps’ or ‘Naps + RT’ with a within-subjects design. Our results demonstrate that adding RT to naps changes sleep architecture, with a significant increase in the TST, mostly due to N2 sleep stage (and N3, to a lesser extent). Therefore, the deepening of short naps with RT involving hypnosis might be a successful non-pharmacological way to extend sleep duration and to deepen sleep in occupational settings.

Association Between a Healthy Lifestyle Score and the Risk of Cardiovascular Disease in the SUN Cohort

Introduction and objectivesA healthy lifestyle (HLS) is essential to attaining optimal cardiovascular health. Our objective was to assess the association between a HLS score and the incidence of hard cardiovascular disease (CVD) events. MethodsThe SUN project is a dynamic, prospective, multipurpose cohort of Spanish university graduates with a retention proportion of 92%. In 19 336 participants, we calculated a HLS score ranging from 0 to 10 points: never smoking, physical activity (> 20 METs-h/wk), Mediterranean diet adherence (≥ 4/8 points), low body mass index (≤ 22), moderate alcohol intake (women, 0.1-5g/d; men, 0.1-10g/d), low television exposure (≤ 2h/d), no binge drinking (≤ 5 alcoholic drinks anytime), taking a short afternoon nap (< 30min/d), meeting up with friends> 1h/d and working> 40h/wk. ResultsAfter a median follow-up of 10.4 years, we identified 140 incident cases of CVD. After adjustment for potential confounders, the highest category of HLS score adherence (7-10 points) showed a significant 78% relative reduction in the risk of primary CVD compared with the lowest category (0-3 points) (adjusted HR, 0.22; 95%CI, 0.11-0.46). Each healthy habit was individually associated with a lower risk of CVD. ConclusionsA HLS score including several simple healthy habits was associated with a lower risk of developing primary CVD. This index may be useful to reinforce CVD prevention without the need to include traditional risk factors.

Effects of a short midday nap on habitual nappers' alertness, mood and mental performance across cognitive domains.

This study examines whether the benefits of a short midday nap on habitual nappers' mental performance depend on the cognitive domain and the task difficulty. Eighteen healthy college students with the long-term habit of a midday nap (13:00-14:00hours) participated in a nap-deprivation study. On two separate days with at least 3days in between, participants either took a nap or remained awake, and were subsequently tested on a simple sustained attention task (Psychomotor Vigilance Test), two more complex attention tasks (Go/No-Go and Flanker task) and one working memory task (2-back). For each task, an easy and a difficult version were administered. The time course of subjective sleepiness and mood were also measured in both napping conditions. The results revealed that short midday nap deprivation significantly impaired participants' performance on both the easy and difficult versions of the Psychomotor Vigilance Test task, as well as accuracy but not reaction speed in the Go/No-Go task. Accuracy in the difficult version of the Flanker task and the 2-back task was also lower in the no-nap condition, while reaction speed in the 2-back task but not the Flanker task was reduced without a nap in both the easy and difficult versions. Moreover, subjective sleepiness was significantly increased after nap deprivation, but moods remained unaffected in the no-nap condition. These findings contribute to current research suggesting that effects of a midday nap on task performance depend on the cognitive domain as well as task difficulty. Our study highlights the importance of considering task characteristics to evaluate the benefits of a regular midday nap in practical working life.

Assessment of performance impairment after short naps with and without sleep inertia

IntroductionNaps can reduce performance deficits and sleepiness, and therefore increase safety. However, sleep inertia – reduced functioning ability after awakening – may reduce the benefits of an otherwise effective sleep. Prior research shows that sleep inertia effects appear minimally after short naps. The aim of the study was to learn about laypersons' assessment of performance capacity following a short nap and ensuing sleep inertia. MethodTwo hundred and fifteen university students were divided into four groups who responded to questionnaires assessing performance levels of a character after a 15-min or a 60-min nap in imaginary scenarios. Tasks were to be executed immediately or an hour after waking from the nap. Respondents rated the extent of fitness of the character to complete each scenario. ResultsThe ability to perform immediately after a 15-min nap was rated as low as after no sleep at all, and worse than immediately following a longer nap. It was also rated as worse than an hour after waking from a 15-min and a one-hour nap. ConclusionLaypersons are aware of the fact that insufficient sleep leads to impaired performance and that longer naps produce better functional recovery but are not aware of the dynamics of changes in the capacity to perform immediately after a nap. Practical ApplicationsIt is recommended that the gap between the knowledge people hold and the knowledge that is reflected in sleep research be reduced both through education in workplaces and mass media.

Relación entre un índice de estilo de vida saludable y el riesgo de enfermedad cardiovascular en la cohorte SUN

Introduction and objectivesA healthy lifestyle (HLS) is essential to attaining optimal cardiovascular health. Our objective was to assess the association between a HLS score and the incidence of hard cardiovascular disease (CVD) events. MethodsThe SUN project is a dynamic, prospective, multipurpose cohort of Spanish university graduates with a retention proportion of 92%. In 19 336 participants, we calculated a HLS score ranging from 0 to 10 points: never smoking, physical activity (> 20 METs-h/wk), Mediterranean diet adherence (≥ 4/8 points), low body mass index (≤ 22), moderate alcohol intake (women, 0.1-5g/d; men, 0.1-10g/d), low television exposure (≤ 2h/d), no binge drinking (≤ 5 alcoholic drinks anytime), taking a short afternoon nap (< 30min/d), meeting up with friends> 1h/d and working> 40h/wk. ResultsAfter a median follow-up of 10.4 years, we identified 140 incident cases of CVD. After adjustment for potential confounders, the highest category of HLS score adherence (7-10 points) showed a significant 78% relative reduction in the risk of primary CVD compared with the lowest category (0-3 points) (adjusted HR, 0.22; 95%CI, 0.11-0.46). Each healthy habit was individually associated with a lower risk of CVD. ConclusionsA HLS score including several simple healthy habits was associated with a lower risk of developing primary CVD. This index may be useful to reinforce CVD prevention without the need to include traditional risk factors.Full English text available from:www.revespcardiol.org/enFull English text available from:www.revespcardiol.org/en

Deep, short sleep naps in occupational settings using relaxation techniques

Introduction: Insufficient sleep is frequently seen in occupational settings (health care professions, drivers, soldiers). The resulting sleep debt leads to daytime sleepiness, fatigue, mood disorder, and cognitive deficits as well as altered vascular, immune and inflammatory responses. Short daytime naps are an efficient way to counteract bad outcomes related to sleep debt and to have positive effects on daytime sleepiness and performance after a normal or restricted night of sleep in adults. However, the environmental settings in working conditions and the emotional state of workers are generally not conducive to beneficial effects.

Upgrading naps in occupational settings: Lengthening and deepening sleep naps with hypnotic suggestions

Purpose: Insufficient sleep is frequently seen in occupational settings (health care professions, drivers, soldiers). The resulting sleep debt leads to daytime sleepiness, fatigue, mood disorder, and cognitive deficits as well as altered vascular, immune and inflammatory responses. Short daytime naps are an efficient way to counteract bad outcomes related to sleep debt and to have positive effects on daytime sleepiness and performance after a normal or restricted night of sleep in adults. However, the environmental settings in working conditions and the emotional state of workers are generally not conducive to beneficial effects.

The Sleeping Infant Brain Anticipates Development

From the age of 3months, infants learn relations between objects and co-occurring words [1]. These very first representations of object-word pairings in infant memory are considered as non-symbolic proto-words comprising specific visual-auditory associations that can already be formed in the first months of life [2-5]. Genuine words that refer to semantic long-term memory have not been evidenced prior to 9months of age [6-9]. Sleep is known to facilitate the reorganization of memories [9-14], but its impact on the perceptual-to-semantic trend in early development is unknown. Here we explored the formation of word meanings in 6- to 8-month-old infants and its reorganization during the course of sleep. Infants were exposed to new words as labels for new object categories. In the memory test about an hour later, generalization to novel category exemplars was tested. In infants who took a short nap during the retention period, a brain response of 3-month-olds [1] was observed, indicating generalizations based on early developing perceptual-associative memory. In those infants who napped longer, a semantic priming effect [15, 16] usually found later in development [17-19] revealed the formation of genuine words. The perceptual-to-semantic shift in memory was related to the duration of sleep stage 2 and to locally increased sleep spindle activity. The finding that, after the massed presentation of several labeled category exemplars, sleep enabled even 6-month-olds to create semantic long-term memory clearly challenges the notion that immature brain structures are responsible for the typically slower lexical development.

Memory in 3-month-old infants benefits from a short nap.

A broad range of studies demonstrate that sleep has a facilitating role in memory consolidation (see Rasch & Born, ). Whether sleep-dependent memory consolidation is also apparent in infants in their first few months of life has not been investigated. We demonstrate that 3-month-old infants only remember a cartoon face approximately 1.5-2hours after its first presentation when a period of sleep followed learning. Furthermore, habituation time, that is, the time to become bored with a stimulus shown repetitively, correlated negatively with the density of infant sleep spindles, implying that processing speed is linked to specific electroencephalographic components of sleep. Our findings show that without a short period of sleep infants have problems remembering a newly seen face, that sleep enhances memory consolidation from a very early age, highlighting the importance of napping in infancy, and that infant sleep spindles may be associated with some aspects of cognitive ability.

Wearable PPG sensor based alertness scoring system.

Quantifying mental alertness in today's world is important as it enables the person to adopt lifestyle changes for better work efficiency. Miniaturized sensors in wearable devices have facilitated detection/monitoring of mental alertness. Photoplethysmography (PPG) sensors through Heart Rate Variability (HRV) offer one such opportunity by providing information about one's daily alertness levels without requiring any manual interference from the user. In this paper, a smartwatch based alertness estimation system is proposed. Data collected from PPG sensor of smartwatch is processed and fed to machine learning based model to get a continuous alertness score. Utility functions are designed based on statistical analysis to give a quality score on different stages of alertness such as awake, long sleep and short duration power nap. An intelligent data collection approach is proposed in collaboration with the motion sensor in the smartwatch to reduce battery drainage. Overall, our proposed wearable based system provides a detailed analysis of alertness over a period in a systematic and optimized manner. We were able to achieve an accuracy of 80.1% for sleep/awake classification along with alertness score. This opens up the possibility for quantifying alertness levels using a single PPG sensor for better management of health related activities including sleep.

Daytime napping and risk of type 2 diabetes: a meta-analysis of prospective studies.

Prospective studies reported inconsistent findings on the relationship between daytime napping and risk of type 2 diabetes (T2D). Categorized and dose-response meta-analyses were performed to quantify this relation. Potentially eligible studies were identified by searching PubMed and Embase databases. Dose-response effects were assessed by the generalized least squares trend estimation and study-specific summary relative risks (RRs) with 95% confidence intervals (CIs) were computed with a random-effects model. Seven prospective studies including one US, four European, and two Chinese cohorts involving 249,077 participants and 13,237 cases of T2D were included. The overall analyses showed a 17% increased risk of T2D when comparing habitual nappers with non-nappers (RR=1.17, 95% CI 1.08-1.27). By region, the summary RR was 1.21 (95% CI 1.17-1.26), 1.15 (95% CI 1.03-1.30) and 1.23 (95% CI 0.87-1.73) for the US, European, and Chinese studies, respectively. Limiting to five studies that excluded subjects with known major chronic disorders yielded a summary RR of 1.16 (95% CI 1.03-1.30). A dose-response analysis suggested an 11% (95% CI 7-16%) increased T2D risk for each increment in daytime napping of 30min/day and, despite no evidence for nonlinearity (P nonlinearity=0.65), the increased risk of T2D for short nap (<50min/day) was dominated by the US study. This meta-analysis suggests that daytime napping is associated with an increased risk of T2D. Given the limited number of cohorts and inconsistency in terms of methodological and population characteristics across these cohorts, residual confounders and/or reverse causality cannot be fully addressed, and our findings should be interpreted with great caution. Future well-designed prospective studies are still warranted.

The Usefulness of Nap Sleep Recording During Routine Electroencephalography: An Audit Study.

A measure to increase the electroencephalogram (EEG) outcome includes a short period of nap sleep during a routine standard EEG with the aim of increasing its sensitivity to interictal abnormalities or provoking seizures. As part of an ongoing auditing of our EEG data, we aimed to investigate the contribution of nap sleep during routine outpatient department based EEGs requested for a variety of reasons. EEG data at the Department of Clinical Physiology at Sultan Qaboos University Hospital, Oman, from July 2006 to December 2007 and from January 2009 to December 2010 (total 42 months) were reviewed. The EEGs were for patients older than 13-years referred for possible epilepsy, blackouts, headache, head trauma, and other non-specified attacks. The recording period was between 20 to 40 minutes. Abnormalities were identified during waking and nap sleep periods. A total of 2 547 EEGs were reviewed and 744 were abnormal (29.2%). Of those abnormal EEGs, nap sleep was obtained in 258 (34.7%) EEGs, and 39 (15.1%) showed abnormalities during nap sleep. Nineteen out of the 39 (48.7%) EEGs were abnormal during awake and nap sleep; and 20 (51.3%) were abnormal during nap sleep, which represented only 2.7% of the total abnormal EEGs (n = 744). The contribution of the short nap sleep to the pickup rate of interictal abnormalities in EEG was minimal. We recommend the EEG service to include one cycle of spontaneous sleep EEG directed at patients with a history suggestive of epilepsy if their awake EEGs are normal.

Somnambulisme avec mise en danger vital (syndrome d’Elpénor) chez un enfant

This 10-year-old girl was admitted at night to our hospital after a 3-m fall at home. She was alert (Glasgow score, 15) at admission; a frontal wound and a deformation of the right wrist were noted. Brain CT scans showed a frontal skull fracture and frontal lobe contusion, wrist x-rays showed a displaced right fracture. The patient underwent urgent neurosurgery (wound excision and suture after reduction of skull fracture) and closed reduction and immobilization of the wrist fracture, both under general anesthesia. She underwent a psychiatric assessment in the intensive care unit 3days after her fall. She was alert, well-oriented in time and space, and spoke fluently. She had no memory of her fall, only remembering going to bed in the evening before the accident and waking up in the ambulance on the way to the hospital. She displayed no sign of a concurrent mental illness and no suicidal ideas. Her parents reported that the evening of the accident she and her two brothers had all fallen asleep about 11:00pm while watching TV, in the double bed of the guest room, placed just beside its window. At approximately 1:00am, her father, who was going to bed and had just made noise in the hall, heard a cry from the guest room. He entered the room immediately and saw the opened window and his daughter lying on the outside ground; the brothers only awakened after the fall. The family had returned 2days before from a 6-month stay in the United States, with jet-lag, sleep deprivation, and a disorganized sleep/wake rhythm in the patient. There was no medication before the accident, no substance use (including caffeine), and no concurrent medical problem. Over the 2preceding years, the patient had undergone two witnessed episodes of early-nighttime arousal with altered consciousness and calm wandering (including going downstairs on one occasion), both strongly suggesting sleepwalking. There was a history of sleepwalking in her father and her older brother. Life-threatening sleepwalking (Elpenor syndrome) was diagnosed. The child and her parents were educated about sleepwalking; regularization of sleep schedules and sleep extension (avoidance of sleep deprivation, short napping when possible) were prescribed. We also recommended securing the home (bed, windows, and stairways). No pharmacological treatment was instituted. During the following 18months, the child manifested only one noted sleepwalking episode, without risk-taking. She had no neurological or psychopathological sequela from her accident, of which she never had a memory. Elpenor syndrome can occur in a child; consequently, it is important to inform parents of children with sleepwalking about the necessity of always securing the night-time environment.

Dependence of nighttime sleep duration in one-month-old infants on alterations in natural and artificial photoperiod

Human sleep–wake cycles are entrained by both natural and artificial light–dark cycles. However, little is known regarding when and how the photoperiod changes entrain the biological clock after conception. To investigate the dependence of sleep patterns in young infants on the natural and artificial light–dark cycles, 1,302 pairs of one-month-old infants and their mothers were asked to answer a questionnaire. Birth in spring, longer daytime sleep duration, early/regular light-off times, and longer maternal nighttime sleep duration were identified as independent variables for longer infant nighttime sleep duration in both univariate and multivariate analyses. Longer maternal nighttime sleep duration was dependent on shorter naps and early/regular bed times but not on the season. We found that nighttime sleep duration depended on both natural and artificial diurnal photoperiod changes in one-month-old infants. Although sleep patterns of infants mimicked those of their mothers, nighttime sleep duration depended on the season, and was positively associated with daytime sleep duration, only in the infants. These specific variables, which render sleep patterns of the infants different from those of their mothers, might be a clue to reveal the covert acquisition process of mature circadian rhythms after birth.

The association between daytime napping and risk of diabetes: a systematic review and meta-analysis of observational studies

ObjectiveTo investigate the association between daytime napping and prevalent/incident diabetes mellitus (DM) based on systematic review and meta-analytic data. MethodsThe electronic databases of Embase, Medline, Pubmed and Web of Science were searched. Relevant studies were extracted by two reviewers independently. The associations between daytime napping (irrespective of duration), long nap (≥1 h/day) and short nap (<1 h/day), and risk of DM were assessed according to study types. Overall estimates were pooled using either fixed- or random-effect with inverse variance meta-analysis. Heterogeneity of included studies was assessed using the I2 test and possible cause of the heterogeneity was examined by meta-regression analyses. ResultsTen studies (four cross-sectional and six longitudinal cohort) comprising a total of 304,885 individuals and 20,857 cases of DM were included in the systematic review, with an average napping prevalence of 47%. Nappers were found to have increased risk of DM in both cross-sectional and cohort studies. However, significant heterogeneity was present. Long nap (≥1 h/day) was associated with both prevalent and incident DM; in particular, those with a daily nap over 1 h had a 31% increased risk of developing DM during follow-up (95% confidence interval: 2–67%). Conversely, no such association was found in individuals with short naps (<1 h/day) in cohort studies. ConclusionsLong daytime napping over 1 h per day was associated with increased risk of both prevalent and incident DM. Further studies are needed to confirm the findings.

Prediagnosis Sleep Duration, Napping, and Mortality Among Colorectal Cancer Survivors in a Large US Cohort.

Prediagnosis lifestyle factors can influence colorectal cancer (CRC) survival. Sleep deficiency is linked to metabolic dysfunction and chronic inflammation, which may contribute to higher mortality from cardiometabolic conditions and promote tumor progression. We hypothesized that prediagnosis sleep deficiency would be associated with poor CRC survival. No previous study has examined either nighttime sleep or daytime napping in relation to survival among men and women diagnosed with CRC. We examined self-reported sleep duration and napping prior to diagnosis in relation to mortality among 4869 CRC survivors in the NIH-AARP Diet and Health Study. Vital status was ascertained by linkage to the Social Security Administration Death Master File and the National Death Index. We examined the associations of sleep and napping with mortality using traditional Cox regression (total mortality) and Compositing Risk Regression (cardiovascular disease [CVD] and CRC mortality). Models were adjusted for confounders (demographics, cancer stage, grade and treatment, smoking, physical activity, and sedentary behavior) as well as possible mediators (body mass index and health status) in separate models. Compared to participants reporting 7-8 hours of sleep per day, those who reported <5 hr had a 36% higher all-cause mortality risk (Hazard Ratio (95% Confidence Interval), 1.36 (1.08-1.72)). Short sleep (<5 hr) was also associated with a 54% increase in CRC mortality (Substitution Hazard Ratio (95% Confidence Interval), 1.54 (1.11-2.14)) after adjusting for confounders and accounting for competing causes of death. Compared to no napping, napping 1 hr or more per day was associated with significantly higher total and CVD mortality but not CRC mortality. Prediagnosis short sleep and long napping were associated with higher mortality among CRC survivors.

Poor Sleep and Risk of Falls in Community-Dwelling Older Adults: A Systematic Review.

Concerns about sleep problems and falls in older adults are significant. This article reviews the association between sleep problems and falls in community-dwelling adults aged 65 years or older. Multiple databases were searched from inception until 2015 using sleep, sleep disorders, and falls as keywords, limiting to studies published in English in peer-reviewed journals. After screening and assessing for eligibility, 18 articles were selected based on the inclusion and exclusion criteria. Findings of an association between sleep problems and risk of falls are conflicting, but some specific sleep problems such as extremely short sleep duration, daytime sleepiness and naps appear to be significantly related to falls in older adults. Methodological limitations including variability in covariates included in the analyses and measurement of the exposure and outcome variables were identified. The results of this review identified the need to have comparable definitions, validated tools, and rigorous design of future studies.

J-curve relation between daytime nap duration and type 2 diabetes or metabolic syndrome: A dose-response meta-analysis.

Adequate sleep is important for good health, but it is not always easy to achieve because of social factors. Daytime napping is widely prevalent around the world. We performed a meta-analysis to investigate the association between napping (or excessive daytime sleepiness: EDS) and the risk of type 2 diabetes or metabolic syndrome, and to quantify the potential dose-response relation using cubic spline models. Electronic databases were searched for articles published up to 2016, with 288,883 Asian and Western subjects. Pooled analysis revealed that a long nap (≥60 min/day) and EDS were each significantly associated with an increased risk of type 2 diabetes versus no nap or no EDS (odds ratio 1.46 (95% CI 1.23–1.74, p < 0.01) for a long nap and 2.00 (1.58–2.53) for EDS). In contrast, a short nap (<60 min/day) was not associated with diabetes (p = 0.75). Dose-response meta-analysis showed a J-curve relation between nap time and the risk of diabetes or metabolic syndrome, with no effect of napping up to about 40 minutes/day, followed by a sharp increase in risk at longer nap times. In summary, longer napping is associated with an increased risk of metabolic disease. Further studies are needed to confirm the benefit of a short nap.

EP 118. Can midday naps boost learning in older adults?

Naps as well as a night of sleep were found to improve motor learning in young individuals (Doyon et al., 2009). The capacity of older adults to learn and stabilize motor memory traces (consolidation) during over-night sleep is limited (Pan and Rickard, 2015, Backhaus et al., 2015). However a small number of studies suggested sleep-dependent consolidation in healthy older adults, immediately after sleep (Gudberg et al., 2015, Al-Sharman and Siengsukon, 2014) or after a delayed period (Tucker et al., 2011, Korman et al., 2015). Can midday naps enhance motor learning in older adults? We evaluated the performance changes of a sample of thirty-three healthy older adults (60–82 years) by implementing a napping paradigm in a motor learning setup (sequence learning and motor adaption). The participants were randomly assigned to one of three groups; short nap group (a forty-five minutes nap opportunity, 10–20 min sleep), long nap group (ninety minutes nap opportunity, 50–80 min sleep) or a forty-five minutes period of wakefulness. Three learning sessions on two consecutive days were compared for both tasks with the repeated measures mixed model approach. All older adults were able to improve their task performance in both tasks throughout all sessions. For sequence learning no differences between the nap groups could be found following the midday nap, nor after an extended period of consolidation, i.e. the following day. Similarly no significant differences between the groups could be found directly after the midday break when performing the motor adaptation task. However during the final block of the last session nappers performed significantly better (p = 0.023) than those adults staying awake. Although midday naps may have a great recuperative value (Tamaki et al., 1999, Campbell et al., 2011), these effects could not be projected on motor learning and subsequent motor performance directly after napping. Based on the current results we conclude that short daytime naps do not enhance the effects of motor learning and consolidation. Thus, deficits in consolidation apparent in older adults are not dependent of the duration of sleep but rather of the process of consolidation during sleep, which seems to be impaired in older adults. This work was supported by the Stiftung der Deutschen Wirtschaft providing a PhD Scholarship to W.B. W.B and F.C.H. hold a research grant from the Werner-Otto-Foundation (9/87).