Bidirectional associations between the duration and timing of nocturnal sleep and daytime naps in adolescents differ from weekdays to weekends.

Study Objectives: Previous studies examining bidirectional relationships between nocturnal sleep and napping have focused on sleep duration, leaving a gap in our understanding of how sleep timing contributes. Here, we assessed the duration and timing for night sleep and daytime naps, to evaluate how the previous night's sleep influences the next day's napping, and how napping influences same-night nocturnal sleep.

Methods: We analyzed sleep diary and actigraphy data from 153 teens (males = 43.

Higher handgrip strength is linked to higher salience ventral attention functional network segregation in older adults.

Converging evidence suggests that handgrip strength is linked to cognition in older adults, and this may be subserved by shared age-related changes in brain function and structure. However, the interplay among handgrip strength, brain functional connectivity, and cognitive function remains poorly elucidated. Hence, our study sought to examine these relationships in 148 community-dwelling older adults.

Influence of mid-afternoon nap duration and sleep parameters on memory encoding, mood, processing speed, and vigilance.

Study Objectives: To determine how mid-afternoon naps of differing durations benefit memory encoding, vigilance, speed of processing (SOP), mood, and sleepiness; to evaluate if these benefits extend past 3 hr post-awakening and to examine how sleep macrostructure during naps modulate these benefits.

Methods: Following short habitual sleep, 32 young adults underwent four experimental conditions in randomized order: wake; naps of 10 min, 30 min, and 60 min duration verified with polysomnography. A 10-min test battery was delivered at a pre-nap baseline, and at 5 min, 30 min, 60 min, and 240 min post-nap.

Bedtime procrastination and chronotype differentially predict adolescent sleep on school nights and non-school nights.

Objectives: Bedtime procrastination (BTP) refers to the tendency to delay sleep beyond an intended bedtime, in favor of continuing evening activities. BTP has been associated with negative sleep outcomes (later timing, shorter duration, poorer quality), and is viewed as a problem of exercising self-control. BTP could be particularly challenging in adolescents, given the combined effects of increasing bedtime autonomy, later chronotype, and a still developing self-control capacity.

Systematic review and meta-analyses on the effects of afternoon napping on cognition.

Naps are increasingly considered a means to boost cognitive performance. We quantified the cognitive effects of napping in 60 samples from 54 studies. 52 samples evaluated memory.

Understanding the Need for Sleep to Improve Cognition.

The restorative function of sleep is shaped by its duration, timing, continuity, subjective quality, and efficiency. Current sleep recommendations specify only nocturnal duration and have been largely derived from sleep self-reports that can be imprecise and miss relevant details. Sleep duration, preferred timing, and ability to withstand sleep deprivation are heritable traits whose expression may change with age and affect the optimal sleep prescription for an individual.

Multi-Night at-Home Evaluation of Improved Sleep Detection and Classification with a Memory-Enhanced Consumer Sleep Tracker.

Purpose: To evaluate the benefits of applying an improved sleep detection and staging algorithm on minimally processed multi-sensor wearable data collected from older generation hardware.

Patients And Methods: 58 healthy, East Asian adults aged 23-69 years (M = 37.10, SD = 13.

A sleep schedule incorporating naps benefits the transformation of hierarchical knowledge.

Study Objectives: The learning brain establishes schemas (knowledge structures) that benefit subsequent learning. We investigated how sleep and having a schema might benefit initial learning followed by rearranged and expanded memoranda. We concurrently examined the contributions of sleep spindles and slow-wave sleep to learning outcomes.

Cortical thinning and sleep slow wave activity reductions mediate age-related improvements in cognition during mid-late adolescence.

Study Objectives: Gains in cognitive test performance that occur during adolescence are associated with brain maturation. Cortical thinning and reduced sleep slow wave activity (SWA) are markers of such developmental changes. Here we investigate whether they mediate age-related improvements in cognition.

Sleep-dependent prospective memory consolidation is impaired with aging.

Study Objectives: Existing literature suggests that sleep-dependent memory consolidation is impaired in older adults but may be preserved for personally relevant information. Prospective memory (PM) involves remembering to execute future intentions in a timely manner and has behavioral importance. As previous work suggests that N3 sleep is important for PM in young adults, we investigated if the role of N3 sleep in PM consolidation would be maintained in older adults.

Splitting sleep between the night and a daytime nap reduces homeostatic sleep pressure and enhances long-term memory.

Daytime naps have been linked with enhanced memory encoding and consolidation. It remains unclear how a daily napping schedule impacts learning throughout the day, and whether these effects are the same for well-rested and sleep restricted individuals. We compared memory in 112 adolescents who underwent two simulated school weeks containing 8 or 6.

Schema-driven memory benefits boost transitive inference in older adults.

Age-related cognitive deficits may be diminished by tapping into prior knowledge structures. We investigated age-related differences in the formation and updating of schemas and examined whether the memory benefits of recently acquired schemas would be preserved in older adults. Data were collected from 60 older adults ( = 66.

Multi-Night Validation of a Sleep Tracking Ring in Adolescents Compared with a Research Actigraph and Polysomnography.

Background: Wearable devices have tremendous potential for large-scale longitudinal measurement of sleep, but their accuracy needs to be validated. We compared the performance of the multisensor Oura ring (Oura Health Oy, Oulu, Finland) to polysomnography (PSG) and a research actigraph in healthy adolescents.

Methods: Fifty-three adolescents (28 females; aged 15-19 years) underwent overnight PSG monitoring while wearing both an Oura ring and Actiwatch 2 (Philips Respironics, USA).

Memory performance following napping in habitual and non-habitual nappers.

Study Objectives: Afternoon naps benefit memory but this may depend on whether one is a habitual napper (HN; ≥1 nap/week) or non-habitual napper (NN). Here, we investigated whether a nap would benefit HN and NN differently, as well as whether HN would be more adversely affected by nap restriction compared to NN.

Methods: Forty-six participants in the nap condition (HN-nap: n = 25, NN-nap: n = 21) took a 90-min nap (14:00-15:30 pm) on experimental days while 46 participants in the Wake condition (HN-wake: n = 24, NN-wake: n = 22) remained awake in the afternoon.

Cognitive effects of split and continuous sleep schedules in adolescents differ according to total sleep opportunity.

Study Objectives: We compared the basic cognitive functions of adolescents undergoing split (nocturnal sleep + daytime nap) and continuous nocturnal sleep schedules when total sleep opportunity was either below or within the recommended range (i.e. 6.

The effects of sleep on prospective memory: A systematic review and meta-analysis.

Prospective memory (PM) enables us to execute previously conceived intentions at a later time and is used when remembering to call a friend or submitting a proposal on time. Evidence that sleep benefits PM is presently mixed. Further, when a benefit is observed, it is unclear if this is achieved through improvements in strategic monitoring (maintaining an intention in mind and searching for cues) or spontaneous retrieval (an automatic process occurring without preparatory attention).

Sleep improves memory for the content but not execution of intentions in adolescents.

Objective: Sleep benefits prospective memory in young adults probably in part due to its well-established role in enhancing declarative memory, thereby facilitating retrieval of the intention content. In prior work on adolescents, we did not detect differences in prospective memory comparing five nights of sleep restriction and adequate sleep. Here, we examined whether this might be attributed to a limited role of sleep in benefiting the declarative content in this age group, and whether a sleep benefit on prospective memory would be uncovered with a shorter retention interval.

Slow wave sleep facilitates spontaneous retrieval in prospective memory.

Study Objectives: Previous studies have shown that sleep benefits prospective memory by facilitating spontaneous retrieval processes. Here, we investigated the sleep features supporting such a benefit.

Methods: Forty-nine young adults (mean age ± SD: 22.

Multiple nights of partial sleep deprivation do not affect prospective remembering at long delays.

Prospective memory is defined as remembering to do something at a particular moment in the future and may be modulated by sleep. Here, we investigated whether multiple nights of partial sleep deprivation would affect the successful retrieval of intentions. Fifty-nine adolescents (mean age ± SD: 16.

Longitudinal brain structure and cognitive changes over 8 years in an East Asian cohort.

Although East Asia harbors the largest number of aging adults in the world, there is currently little data clarifying the longitudinal brain-cognition relationships in this group. Here, we report structural MRI and neuropsychological findings from relatively healthy Chinese older adults of the Singapore-Longitudinal Aging Brain Study cohort over 8 years of follow up (n=111, mean age=67.1 years, range=56.

Sleep deprivation increases formation of false memory.

Retrieving false information can have serious consequences. Sleep is important for memory, but voluntary sleep curtailment is becoming more rampant. Here, the misinformation paradigm was used to investigate false memory formation after 1 night of total sleep deprivation in healthy young adults (N = 58, mean age ± SD = 22.

Cognitive Performance, Sleepiness, and Mood in Partially Sleep Deprived Adolescents: The Need for Sleep Study.

Study Objectives: To investigate the effects of sleep restriction (7 nights of 5 h time in bed [TIB]) on cognitive performance, subjective sleepiness, and mood in adolescents.

Methods: A parallel-group design was adopted in the Need for Sleep Study. Fifty-six healthy adolescents (25 males, age = 15-19 y) who studied in top high schools and were not habitual short sleepers were randomly assigned to Sleep Restriction (SR) or Control groups.