SleepNCT04984824
Effects of Varying Duration of Naps on Cognitive Performance and Memory Encoding
A study testing Nap duration in people with Sleep, run by Duke-NUS Graduate Medical School at 1 site in Singapore.
Trial summary
To evaluate the nap duration that achieves maximal cognitive gain with practicality of implementation, the present work employs a within-subject design comparing nap durations of 10 minutes, 30 minutes, and 60 minutes with a no nap condition on benefits to alertness, vigilance, mood, speed of processing and memory… Read more about this study
- Who is it for?
- Ages 21 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Sleep
- What is being tested?
- Nap duration
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteSingapore
- Study dates
- 1 Nov 2020to 15 Jun 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Participants aged from 21 - 35 years and who have an average sleep duration of 6-6.5 h are eligible for this study.
Who cannot join
- Participants who have an average sleep duration of less than 6 h or more than 6.5 h, who report sleep apnea symptoms, who report drinking more than 5 cups of caffeinated drinks a day, who have a BMI greater or equal to 30, or report elevated depression or anxiety symptoms will be excluded.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Comparing the Effects of 10, 30 and 60 Minute Naps on Cognitive Performance and Memory Encoding
To evaluate the nap duration that achieves maximal cognitive gain with practicality of implementation, the present work employs a within-subject design comparing nap durations of 10 minutes, 30 minutes, and 60 minutes with a no nap condition on benefits to alertness, vigilance, mood, speed of processing and memory over post-nap intervals of 5 minutes, 30 minutes, 60 minutes and 240 minutes. The effect of nap duration on memory encoding will also be examined.
Read the detailed description
Naps are a global phenomenon and a commonly adopted lifestyle countermeasure to reduce sleepiness and performance impairments. Experimental studies have also shown that naps can improve cognitive functioning and enhance memory and mood. However, the implementation of naps is highly varied amongst individuals, and it remains uncertain what duration of naps achieves the greatest cognitive benefit. Given the potential for naps to boost productivity in societies such as ours where insufficient nocturnal sleep is prevalent and where work hours are long, an investigation of the optimal nap duration is warranted.
Previous studies suggest that the benefits of brief naps (5-15 minutes) occur immediately after the nap and last a limited period (1-3 hours). Longer naps (>30 minutes) are more likely to produce some temporary decrements due to sleep inertia but have the potential to improve cognitive performance for a more sustained period. These findings need to be strengthened through replication and extended to include memory measures that are evaluated over a longer post-nap testing period. To evaluate the nap duration that achieves maximal cognitive gain with practicality of implementation, the present work employs a within-subject design comparing nap durations of 10 minutes, 30 minutes, and 60 minutes with a no nap condition on benefits to alertness, vigilance, mood, speed of processing and memory over post-nap intervals of 5 minutes, 30 minutes, 60 minutes and 240 minutes. The effect of nap duration on memory encoding will also be examined.
The investigator's findings are expected to inform theoretical models of sleep and cognition and will aid in the design of practical lifestyle strategies to alleviate sleepiness and improve cognitive performance that may be adopted in an everyday context to boost societal well-being and productivity.
- Conditions
- Sleep
- Being tested
- Nap duration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nap durationBehavioural
A cognitive battery which will be repeated at 1505, 1530, 1600 and 1900. Material for the picture encoding task will be learned at 1630 and will be tested at 2000.
| Study group | Role | What they receive |
|---|---|---|
| No nap group | No intervention | No nap opportunity will be given in this condition. |
| 10 minute nap | Experimental | Participants will be given a 10 minute nap. Receives: Behavioral: Nap duration |
| 30 minute nap | Experimental | Participants will be given a 30 minute nap. Receives: Behavioral: Nap duration |
| 60 minute nap | Experimental | Participants will be given a 60 minute nap. Receives: Behavioral: Nap duration |
What is being measured
The primary outcome is the main question the study is designed to answer.
Picture encoding task
Participants will observe pictures of non-famous people, landscapes, scenes and objects. Later they are tested on whether they remember seeing the picture previously or not. The encoding session will take 20-30 min, and the retrieval session will take 15 min.
Measured: In total: 35-45 min
Levels of sleepiness
Karolinska Sleepiness Scale. Participants rated their level of subjective sleepiness on a 9-point Likert scale (1 - very alert, 9 - very sleepy, great effort to keep awake).
Measured: 1 min
Mood
Positive and Negative Affect Scale. On the Positive and Negative Affect Scale (PANAS), participants responded to 20 adjectives describing positive and negative mood states on a 5-point Likert scale (1 - very slightly, 5 - extremely). Positive and negative affect scores are represented by the sum of the item responses.
Measured: 1 min
Vigilance
Psychomotor Vigilance Test. The 3-min PVT assessed levels of sustained attention. At intervals varying randomly from 2000 ms to 10000 ms, a counter on the screen appeared and participants were to press a key as quickly as possible. Lapses were defined as responses exceeding 500 ms.
Measured: 3 min
Speed of processing
Digit Symbol Substitution Test. The 2-min DSST was used as a measure of speed of processing. In this task, participants were required to match symbols to digits as quickly as possible following a key shown on screen. The total number of correct trials was used as the critical measure.
Measured: 2 min
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Aug 2021
- Study start1 Nov 2020
- Primary completion15 Jun 2021
- Study completion15 Jun 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for SleepStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Duke-NUS Graduate Medical School
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Michael WL Chee, MBBS, Duke-NUS Graduate Medical School
- Investigators
- Michael Chee, MBBS, Principal investigator, National University of Singapore
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04984824
- Sponsor's protocol ID
- NapTitration
- Status last verified
- Jul 2021
- First submitted
- 15 Mar 2021
- Last updated
- 2 Aug 2021
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Leong RLF, Lau T, Dicom AR, Teo TB, Ong JL, Chee MWL. Influence of mid-afternoon nap duration and sleep parameters on memory encoding, mood, processing speed, and vigilance. Sleep. 2023 Apr 12;46(4):zsad025. doi: 10.1093/sleep/zsad025.
PubMed 36775965
Study at a glance
From the registry record, last updated by the sponsor on 2 Aug 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparing the Effects of 10, 30 and 60 Minute Naps on Cognitive Performance and Memory Encoding
- ClinicalTrials.gov ID
- NCT04984824
- Acronym / sponsor ID
- NapTitration
- Conditions
- Sleep
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Duke-NUS Graduate Medical SchoolUniversity, hospital or other
- Study start
- 1 Nov 2020 (actual)
- Primary completion
- 15 Jun 2021 (actual)
- Study completion
- 15 Jun 2021 (actual)
- First posted
- 2 Aug 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To evaluate the nap duration that achieves maximal cognitive gain with practicality of implementation, the present work employs a within-subject design comparing nap durations of 10 minutes, 30 minutes, and 60 minutes with a no nap condition on benefits to alertness, vigilance, mood, speed of processing and memory over post-nap intervals of 5 minutes, 30 minutes, 60 minutes and 240 minutes. The effect of nap duration on memory encoding will also be examined.
Detailed description
Naps are a global phenomenon and a commonly adopted lifestyle countermeasure to reduce sleepiness and performance impairments. Experimental studies have also shown that naps can improve cognitive functioning and enhance memory and mood. However, the implementation of naps is highly varied amongst individuals, and it remains uncertain what duration of naps achieves the greatest cognitive benefit. Given the potential for naps to boost productivity in societies such as ours where insufficient nocturnal sleep is prevalent and where work hours are long, an investigation of the optimal nap duration is warranted.
Previous studies suggest that the benefits of brief naps (5-15 minutes) occur immediately after the nap and last a limited period (1-3 hours). Longer naps (>30 minutes) are more likely to produce some temporary decrements due to sleep inertia but have the potential to improve cognitive performance for a more sustained period. These findings need to be strengthened through replication and extended to include memory measures that are evaluated over a longer post-nap testing period. To evaluate the nap duration that achieves maximal cognitive gain with practicality of implementation, the present work employs a within-subject design comparing nap durations of 10 minutes, 30 minutes, and 60 minutes with a no nap condition on benefits to alertness, vigilance, mood, speed of processing and memory over post-nap intervals of 5 minutes, 30 minutes, 60 minutes and 240 minutes. The effect of nap duration on memory encoding will also be examined.
The investigator's findings are expected to inform theoretical models of sleep and cognition and will aid in the design of practical lifestyle strategies to alleviate sleepiness and improve cognitive performance that may be adopted in an everyday context to boost societal well-being and productivity.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| No nap group | No intervention | –No nap opportunity will be given in this condition. |
| 10 minute nap | Experimental | Behavioral: Nap durationParticipants will be given a 10 minute nap. |
| 30 minute nap | Experimental | Behavioral: Nap durationParticipants will be given a 30 minute nap. |
| 60 minute nap | Experimental | Behavioral: Nap durationParticipants will be given a 60 minute nap. |
Who may qualify
- Ages
- 21 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Participants aged from 21 - 35 years and who have an average sleep duration of 6-6.5 h are eligible for this study.
Key exclusion criteria (1 listed)
- Participants who have an average sleep duration of less than 6 h or more than 6.5 h, who report sleep apnea symptoms, who report drinking more than 5 cups of caffeinated drinks a day, who have a BMI greater or equal to 30, or report elevated depression or anxiety symptoms will be excluded.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Nap durationA cognitive battery which will be repeated at 1505, 1530, 1600 and 1900. Material for the picture encoding task will be learned at 1630 and will be tested at 2000. | Behavioural | 10 minute nap, 30 minute nap, 60 minute nap |
Primary outcome
Picture encoding task
Time frame: In total: 35-45 min
Participants will observe pictures of non-famous people, landscapes, scenes and objects. Later they are tested on whether they remember seeing the picture previously or not. The encoding session will take 20-30 min, and the retrieval session will take 15 min.
Levels of sleepiness
Time frame: 1 min
Karolinska Sleepiness Scale. Participants rated their level of subjective sleepiness on a 9-point Likert scale (1 - very alert, 9 - very sleepy, great effort to keep awake).
Mood
Time frame: 1 min
Positive and Negative Affect Scale. On the Positive and Negative Affect Scale (PANAS), participants responded to 20 adjectives describing positive and negative mood states on a 5-point Likert scale (1 - very slightly, 5 - extremely). Positive and negative affect scores are represented by the sum of the item responses.
Vigilance
Time frame: 3 min
Psychomotor Vigilance Test. The 3-min PVT assessed levels of sustained attention. At intervals varying randomly from 2000 ms to 10000 ms, a counter on the screen appeared and participants were to press a key as quickly as possible. Lapses were defined as responses exceeding 500 ms.
Speed of processing
Time frame: 2 min
Digit Symbol Substitution Test. The 2-min DSST was used as a measure of speed of processing. In this task, participants were required to match symbols to digits as quickly as possible following a key shown on screen. The total number of correct trials was used as the critical measure.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Aug 2021.
- Derived from this study: PubMed 36775965Leong RLF, Lau T, Dicom AR, Teo TB, Ong JL, Chee MWL. Influence of mid-afternoon nap duration and sleep parameters on memory encoding, mood, processing speed, and vigilance. Sleep. 2023 Apr 12;46(4):zsad025. doi: 10.1093/sleep/zsad025.
- Individual participant dataSharing planned: No
Related trials for Sleep
Recruiting
NightWare and Cardiovascular Health in Women With PTSD
Post Traumatic Stress Disorder, Cardiovascular Diseases
Recruiting
Addressing Nocturia in Older Women Utilizing Behavioral Sleep Intervention and Brief Mindfulness
Nocturia, Insomnia
Recruiting
Metabolic Health, Bones and Nuts During Weight Loss in Adults
Weight Loss, Bone Density
Recruiting
Investigation of the Effects of Sleep Deprivation on Itch and Pain Sensitivity
Histamine, Cowhage
Not yet recruiting
REM Enhancement Sleep Technology for Well-being, Emotion, and Life Lift
Healthy Adult Participants
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Michael Chee, MBBS principal investigator
National University of Singapore
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Nap duration in people with Sleep, run by Duke-NUS Graduate Medical School at 1 site in Singapore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 2 Aug 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Picture encoding task (time frame: In total: 35-45 min). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04984824, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Aug 2021.