Naps for Infant Memory Development
Recruiting in Palo Alto (17 mi)
Age: < 18
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: University of Massachusetts, Amherst
Disqualifiers: Premature birth, Developmental delays, Visual disability, others
No Placebo Group
Trial Summary
What is the purpose of this trial?
This study is designed to investigate developmental changes in naps and nap function on memory from 9 to 15 months of age. Memory is measured by a task in which the experimenter interacts with a toy and the measure of memory is whether the child imitates that action when given the toy. Sleep is assessed with a watch that detects motion which provides an estimate of sleep and a set of electrodes placed on the head that measures brain activity during sleep. Infants are recruited at 9 months and sleep and memory are measured again 3- and 6-months later. At each visit, memory is tested before and after a nap (either the morning or afternoon nap) and naps are recorded with the sleep electrodes.
Will I have to stop taking my current medications?
The trial information does not specify whether participants must stop taking their current medications.
What data supports the effectiveness of the treatment Biphasic Sleep, Segmented Sleep, Bimodal Sleep, Polyphasic Sleep in infancy for memory development?
Is napping safe for infants and young children?
How does the treatment of naps for infant memory development differ from other treatments?
This treatment is unique because it involves using two naps per day to enhance memory retention in infants, rather than relying on medications or other interventions. The study found that taking both morning and afternoon naps helps infants remember better, highlighting the importance of nap timing and frequency for memory development.1591011
Eligibility Criteria
This trial is for infants aged 9 to 15 months to explore how napping affects their memory. Infants must be healthy with no sleep disorders like narcolepsy. They'll wear a motion-detecting watch and have electrodes on their head during naps at the study visits, which happen every three months.Inclusion Criteria
Infants must be willing and able to return for testing in 3 and 6 months (e.g., no plans to move out of the area)
My child is 9 months old.
My baby was born with a normal weight and at full term.
Exclusion Criteria
Infants with a score <85 on cognitive and language composite scales and/or <80 on the average of the two composites of the Bayley Scales of Infant Development Fourth Edition (BSID-IV) administered at the first session
Infants with motor development (gross and fine motor) assessed using the BSID-IV, and an adjusted cutoff of 73 will be used to exclude infants with significant motor delays
Infants receiving services due to developmental delays
See 6 more
Trial Timeline
Screening
Participants are screened for eligibility to participate in the trial
4 days
1 visit (in-person)
Initial Assessment
Infants are fitted with an actigraph watch and caregivers complete questionnaires
4 days
1 visit (in-person)
Wave 1 (9 months)
Infants undergo memory tasks and nap/wake conditions are tested
1 week
2 visits (in-person)
Wave 2 (12 months)
Procedures from Wave 1 are repeated at 12 months
1 week
2 visits (in-person)
Wave 3 (15 months)
Procedures from Wave 1 are repeated at 15 months
1 week
2 visits (in-person)
Follow-up
Participants are monitored for memory accuracy and developmental changes
3 months
Treatment Details
Interventions
- Biphasic Sleep (Behavioural Intervention)
Trial OverviewThe study tests if there's a change in how babies remember things before and after they nap. Researchers will see if the way infants imitate actions with toys changes over time, from ages 9 to 15 months, by observing them before and after morning or afternoon naps.
Participant Groups
2Treatment groups
Experimental Treatment
Group I: Wake (non-nap)Experimental Treatment1 Intervention
Wake is promoted
Group II: NapExperimental Treatment1 Intervention
Naps are promoted
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
University of Massachusetts, AmherstAmherst, MA
Loading ...
Who Is Running the Clinical Trial?
University of Massachusetts, AmherstLead Sponsor
University of Maryland, College ParkCollaborator
References
The memory benefits of two naps per day during infancy: A pilot investigation. [2022]In infancy, sleep occurs in multiple nap and overnight bouts that change developmentally in quantity and distribution. Though studies suggest that infant memory benefits from a single nap, no work has assessed the relative benefits of different naps (morning vs. afternoon), nor how multiple naps support memory across the day. We investigated the memory benefit of a morning nap, relative to morning wake, and the effect of these intervals on afternoon nap function in 9-month-olds (n = 15). Infants participated in two within-subjects conditions (separated by 1-2 weeks). In the Nap-Nap condition, infants took their morning and afternoon naps; in the Wake-Nap condition, infants were kept awake during morning naptime, but napped unrestricted in the afternoon. Before each nap/wake interval, infants completed an imitation memory task, with memory assessed again shortly after the nap/wake interval. In the Nap-Nap condition, infants showed memory retention across morning and afternoon naps. In contrast, infants tended to forget items learned across morning wake in the Wake-Nap condition. Moreover, morning wake was associated with a significant decline in post-nap retention of items learned in the afternoon. Furthermore, relations between nap slow-wave activity (SWA) and memory varied across naps, with SWA either not predicting (morning naps) or positively predicting (afternoon naps) memory change in the Nap-Nap condition, but negatively predicting afternoon memory change in the Wake-Nap condition. We conclude that two naps per day (rather than one) aids memory at 9 months, and that skipping the morning nap may moderate relations between afternoon nap physiology and memory.
Measuring Neural Mechanisms Underlying Sleep-Dependent Memory Consolidation During Naps in Early Childhood. [2021]Sleep is critical for daily functioning. One important function of sleep is the consolidation of memories, a process that makes them stronger and less vulnerable to interference. The neural mechanisms underlying the benefit of sleep for memory can be investigated using polysomnography (PSG). PSG is a combination of physiological recordings including signals from the brain (EEG), eyes (EOG), and muscles (EMG) that are used to classify sleep stages. In this protocol, we describe how PSG can be used in conjunction with behavioral memory assessments, actigraphy, and parent-report to examine sleep-dependent memory consolidation. The focus of this protocol is on early childhood, a period of significance as children transition from biphasic sleep (consisting of a nap and overnight sleep) to monophasic sleep (overnight sleep only). The effects of sleep on memory performance are measured using a visuospatial memory assessment across periods of sleep and wakeful-rest. A combination of actigraphy and parent report is used to assess sleep rhythms (i.e., characterizing children as habitual or non-habitual nappers). Finally, PSG is used to characterize sleep stages and qualities of those stages (such as frequencies and the presence of spindles) during naps. The advantage of using PSG is that it is the only tool currently available to assess sleep quality and sleep architecture, pointing to the relevant brain state that supports memory consolidation. The main limitations of PSG are the length of time it takes to prepare the recording montage and that recordings are typically taken over one sleep bought. These limitations can be overcome by engaging young participants in distracting tasks during application and combining PSG with actigraphy and self/parent-report measures to characterize sleep cycles. Together, this unique combination of methods allows for investigations into how naps support learning in preschool children.
The effect of napping and nighttime sleep on memory in infants. [2021]During the first year of life, infants devote the majority of their time to sleep. Research in adults has shown that sleep supports a variety of memory processes. Surprisingly, sleep's function for infant memory has only started to receive attention in research. In this chapter, we will describe age-related changes in sleep and in memory processing over the first years of life, as well as methods to capture both sleep and memory. Then, we will review current findings on the effects of sleep on memory processing in infants. Lastly, we will also point out gaps in current knowledge and describe potential avenues for future research. Overall, the results of recent experimental studies provide evidence that timely, extended napping is involved in how memories are encoded and stored in the long-term and contribute to the formation of knowledge networks in infants.
Sleep spindles in midday naps enhance learning in preschool children. [2021]Despite the fact that midday naps are characteristic of early childhood, very little is understood about the structure and function of these sleep bouts. Given that sleep benefits memory in young adults, it is possible that naps serve a similar function for young children. However, children transition from biphasic to monophasic sleep patterns in early childhood, eliminating the nap from their daily sleep schedule. As such, naps may contain mostly light sleep stages and serve little function for learning and memory during this transitional age. Lacking scientific understanding of the function of naps in early childhood, policy makers may eliminate preschool classroom nap opportunities due to increasing curriculum demands. Here we show evidence that classroom naps support learning in preschool children by enhancing memories acquired earlier in the day compared with equivalent intervals spent awake. This nap benefit is greatest for children who nap habitually, regardless of age. Performance losses when nap-deprived are not recovered during subsequent overnight sleep. Physiological recordings of naps support a role of sleep spindles in memory performance. These results suggest that distributed sleep is critical in early learning; when short-term memory stores are limited, memory consolidation must take place frequently.
Nap timing makes a difference: Sleeping sooner rather than later after learning improves infants' locomotor problem solving. [2022]Twenty-nine newly-walking infants who had recently given up crawling trained to navigate a shoulder-height, nylon tunnel to reach a caregiver waiting at the other end. Infants in the Nap First group napped within 30 min of initial training. Infants in the Delay First group napped four hours after training. All infants were retested six hours after training on the same locomotor problem. Learning was measured by the number of training prompts required to solve the task, exploration, and time to solve the problem. Nap First infants benefited the most from a nap; they required fewer training prompts, used fewer posture shifts from training to test, and solved the task faster compared to Delay First infants, suggesting that optimally timed sleep does not merely protect against interference, but actively contributes to memory consolidation. This study highlights the importance of nap timing as a design feature and was a first step towards limit-testing the boundaries of the relation between sleep and learning. Infants' fragile memories require regular consolidation with intermittent periods of sleep to prevent interference or forgetting.
Early childhood naps initiate emotional memory processing in preparation for enhanced overnight consolidation. [2023]Early childhood naps support emotional memory, but benefits are only observed after overnight sleep. Whether emotional memory consolidation occurs during naps, or whether napping only prepares memories for overnight consolidation is unknown. We investigated whether naps protect emotional memories from interference, indicating consolidation. Between 2018 and 2020, 63 children in western Massachusetts preschools (30 female, 33 male; 33-67 months; 23.8% Hispanic, 87.3% White) learned faces paired with negative or neutral descriptions, followed by nap or wake. Before delayed recognition, half completed an interference task. Without interference, napping benefited recognition. With interference, children recognized fewer negative faces post-nap (compared to wake), with overnight sleep attenuating this difference. Results suggest that naps initially destabilize emotional memories, possibly reflecting partial processing that promotes long-term consolidation.
Slow wave sleep in naps supports episodic memories in early childhood. [2021]Naps have been shown to benefit visuospatial learning in early childhood. This benefit has been associated with sleep spindles during the nap. However, whether young children's naps and their accompanying physiology benefit other forms of declarative learning is unknown. Using a novel storybook task, we found performance in children (N = 22, mean age = 51.23 months) was better following a nap compared to performance following an equivalent interval spent awake. Moreover, performance remained better the following day if a nap followed learning. Change in post-nap performance was positively associated with the amount of time spent in slow wave sleep during the nap. This suggests that slow wave sleep in naps may support episodic memory consolidation in early childhood. Taken in conjunction with prior work, these results suggest that multiple features of brain physiology during naps may contribute to declarative memory processing in early childhood.
Napping facilitates word learning in early lexical development. [2018]Little is known about the role that night-time sleep and daytime naps play in early cognitive development. Our aim was to investigate how napping affects word learning in 16-month-olds. Thirty-four typically developing infants were assigned randomly to nap and wake groups. After teaching two novel object-word pairs to infants, we tested their initial performance with an intermodal preferential looking task in which infants are expected to increase their target looking time compared to a distracter after hearing its auditory label. A second test session followed after approximately a 2-h delay. The delay contained sleep for the nap group or no sleep for the wake group. Looking behaviour was measured with an automatic eye-tracker. Vocabulary size was assessed using the Oxford Communicative Development Inventory. A significant interaction between group and session was found in preferential looking towards the target picture. The performance of the nap group increased after the nap, whereas that of the wake group did not change. The gain in performance correlated positively with the expressive vocabulary size in the nap group. These results indicate that daytime napping helps consolidate word learning in infancy.
[Don Quixote de la Mancha and the description of biphasic sleep in Spanish literature]. [2023]Biphasic or segmented sleep is the habit of sleeping a first and a second sleep separated by a watching. The historian A Ekirch found that this was how people slept in pre-industrial times before the powerful artificial lighting. He is based on texts in different languages, from Antiquity to the 20th century, but the absence of sources in Spanish is striking.
Developmental changes in retention and generalization of nonadjacent dependencies over a period containing sleep in 18-mo-old infants. [2023]Sleep promotes the stabilization of memories in adulthood, with a growing literature on the benefits of sleep for memory in infants and children. In two studies, we examined the role of sleep in the retention and generalization of nonadjacent dependencies (NADs; e.g., a-X-b/c-X-d phrases) in an artificial language. Previously, a study demonstrated that over a delay of 4 h, 15 mo olds who nap after training retain a general memory of the NAD rule instead of memory for specific NADs heard during training. In experiment 1, we designed a replication of the nap condition used in the earlier study but tested 18-mo-old infants. Infants of this age retained veridical memory for specific NADs over a delay containing sleep, providing preliminary evidence of the development of memory processes (experiment 1). In experiment 2, we tested 18 mo olds' ability to generalize the NAD to new vocabulary, finding only infants who napped after training generalized their knowledge of the pattern to completely novel phrases. Overall, by 18 mo of age, children retain specific memories over a period containing sleep, and sleep promotes abstract memories to a greater extent than wakefulness.
Memory in 3-month-old infants benefits from a short nap. [2019]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 1.5-2 hours 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.