The Sleep and Cognition Laboratory (SCL), formerly called the Cognitive Neuroscience Laboratory is a multidisciplinary research team that is dedicated to improving human cognitive performance, health and wellbeing through is research on the benefits of sleep on cognition and conversely the neurobehavioral effects of sleep loss or fragmentation. Alongside, we seek to better understand how sleep can be optimized to improve cognitive aging.

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New publication: On COVID-19 related mobility reduction

During the COVID-19 lockdown periods, we collected wearable data from working adults in order to characterise how COVID-19 associated mobility restrictions changed sleep and physical activity patterns, compared to before the lockdown periods.

Click here to access the article.


Podcast: The Only Thing Your Wearable Sleep Tracker Is Good For

Fitbit sleep trackers made the cash register ring 16 million times in 2019, according to one report. But how much of the sleep data is actually usable? Dr. Michael Chee says there is one nugget of data from a wearable sleep tracker that you can depend on, and that deals with whether there’s an overall trend. Sleep staging? Nope. Sleep quality? Nope. Sleep duration? Yeah, kinda.

Click here to give it a listen.


The results of Need for Sleep 5 are published!

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. 6.5 or 8 h).

The article can be accessed here.


Commentary: Immobility during COVID-19 and its effects on our sleep, physical activity and well-being

COVID-19 has changed the way we work, play and sleep. There are different strategies to better cope, says Yong Loo Lin School of Medicine’s Michael Chee.

Read more here.


Commentary: Not enough time? Transforming work and sleeping better in a digital world

Transforming current work and study habits to allow for more sleep and more efficient time use will result in better cognitive performance, wellbeing and health, says Yong Loo Lin School of Medicine’s Michael Chee.

Read more here.


Commentary: Always tired yet can’t fall asleep? It’s a wake-up call to sleep better

Insomnia can persist and when entrenched can be a misery. So start sleeping better now, says Duke-NUS Medical School’s Michael Chee.

Read more here.


ST Podcast: Why sleep habits need to be formed when young

Are we sleeping more than our neighbours in the region? We all know we should prioritise sleep but many of us don't get a full night's sleep. Can we make up for the lack of sleep on weekends, or by taking afternoon naps? What causes insomnia and is it normal for the elderly to have poor sleep? These and other questions have been answered by Prof. Michael Chee in this podcast.

The podcast can be accessed here.

ST Podcast, episode 2: Can schools and parents help boost the cognition and well-being of sleep-deprived Singaporean teenagers?

What can be done to help teenagers - inundated with homework, curricular activities, enrichment classes and tuition after school - sleep more? Could shorter sleep increase the risk of diabetes among young Singaporeans? How can students manage better sleep strategy during intense examination periods? In this podcast, Prof. Michael Chee continues answering important questions about healthy sleep habits.

The podcast can be accessed here.


The results of Need for Sleep 4 are published!

Many adolescents are exposed to sleep restriction on school nights. We assessed how different apportionment of restricted sleep (continuous versus split sleep) influences neurobehavioral function and glucose levels.

The article can be accessed here.


Recent Publications

15 September 2019

We compared the quality and consistency in sleep measurement of a consumer wearable device and a research-grade actigraph with polysomnography (PSG) in adolescents.

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28 June 2019


Sleep aids the encoding and consolidation of declarative memories, but many adolescents do not obtain the recommended amount of sleep each night. After a normal night of sleep, there is abundant evidence that a daytime nap enhances the consolidation of material learned before sleep and also improves the encoding of new information upon waking. However, it remains unclear how learning is affected when sleep is split between nocturnal and daytime nap periods during a typical school week of restricted sleep. We compared long-term memory in 58 adolescents who underwent two simulated school weeks of suboptimal continuous (6.5 h nocturnal sleep opportunity) or split sleep (5 h nocturnal sleep +1.5 h daytime nap at 14:00).

View the full article here.

October 2019


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). We conducted a meta-analysis of 24 independent samples (N = 165,432) to quantify the effect of sleep on PM and gain clarity regarding the retrieval process benefitted by sleep. Cohen's d with 95% confidence intervals (CI95) were derived using random-effects models. The benefit of sleep on PM was statistically significant and in the small to medium range (d = 0.41, CI95 = 0.25–0.56). Moreover, sleep did not appear to influence monitoring (d = −0.11, CI95 = −0.40–0.17). In contrast, the benefits of sleep are significantly greater when the likelihood of spontaneous retrieval is high (d = 0.94, CI95 = 0.44–1.44) versus low (d = 0.45, CI95 = −0.02–0.93), suggesting that sleep may leverage on spontaneous retrieval processes to improve PM. These findings inform theoretical models of sleep and PM that could sharpen strategies to improve memory function in vulnerable populations. View full article

2 April 2019


Preparatory control of attention facilitates the efficient processing and encoding of an expected stimulus. However, this can occur at the expense of increasing the processing cost of unexpected stimuli. Preparatory control can be influenced by motivational factors, such as the expectation of a reward. Interestingly, expectation of a high reward can increase target processing, as well as reduce the cost associated with reorienting. Using a semantic cueing paradigm, we examined the interaction of reward expectation and cue-validity on semantic judgment performance and subsequent memory. Preparatory attention was assessed with pupillometry. Valid category cueing was associated with better semantic judgment performance and better subsequent memory compared to invalidly cued items. Higher reward also resulted in a larger pre-target pupil diameter, which could be indicative of increased preparatory task engagement or arousal. Critically, higher reward also reduced reorienting cost in both semantic judgment and subsequent memory performance. Our findings suggest that reward expectation can facilitate the effective control of preparatory attention for semantic information, and can support optimal goal-directed behavior based on changing task demands. View full article


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Of Interest

Adolescent Sleep and Educational Performance

We know that sleep is fundamental for learning, memory consolidation and information processing, alongside restoration and repair of the body. Adolescents are particularly vulnerable to sleep disruption around puberty, as both physical and behavioural changes impact upon sleep, which, in turn, can influence their ability to engage in the classroom and learn.

Impact : Journal of the Chartered College of Teaching | Feb 2018

F1: How crashing out helps win races

"F1 drivers are looking for every edge, every advantage and sleep is one of the tools they can use to make sure they are at optimal performance." - Steven Lockley, Harvard Medical School

CNN | 14 Sep 2017

Sleep regularity is important for the happiness and well-being of college students

We found that week-long irregular sleep schedules are significantly associated with lower self-reported morning and evening happiness, healthiness, and calmness during the week even after controlling for weekly average sleep duration," said lead author Akane Sano, PhD, research scientist in the Media Lab Affective Computing Group at the Massachusetts Institute of Technology in Cambridge.

Medical Xpress | 5 Jun 2017

Later school start times in the U.S. : An economic analysis

Recent report by RAND corporation showed that delaying school start times to 8:30 a.m. is a cost-effective, population-level strategy which could have a significant impact on public health and the U.S. economy.

RAND Corporation | 31 Aug 2017

Fatigue and Training Gaps Spell Disaster at Sea, Sailors Warn

In interviews, more than a dozen current and former ship commanders who served in the western Pacific said the strain on the Navy's fleet there had caused maintenance gaps and training shortfalls that had not been remedied or had received only cursory attention as leaders focused on immediate missions.

The New York Times | 27 Aug 2017

NeuroImage is third ranked in the category of Health and Medical Sciences under the subcategory of Neurology and is 64 in the overall list. Within NeuroImage, one of our better-known works within the last 5 years is our piece on functional connectivity in sleep deprived persons (De Havas).

Google Scholar Metrics 2017

Parenting Made Easy - Good Sleep Habits
Sleep hygiene and encouraging good sleeping habits is our focus this week. The importance of children getting enough sleep. How can this help children learn better, and lead a healthy lifestyle?

Parenting Made Easy | 2 Jun 2017

Voices Of Youth : No downside to starting school late

"I am more awake in class and able to concentrate better. I can last longer before feeling tired."

The Straits Times | 19 Jul 2017

More schools should take leaf out of Nanyang's book

I support Professor Michael Chee's call for more schools to emulate Nanyang Girls' High School by implementing a later start time. Given the scientific evidence in favour of this, there is no time to lose. The scale-up of such a scheme, however, can succeed only if the interests of other stakeholders, such as parents, teachers and transport operators, are also considered.

TODAY | 2 Jun 2017

Letting students sleep in is a move worth emulating

Despite numerous medical studies supporting links between short sleep duration and diabetes, obesity, and the metabolic syndrome, many doctors are largely unaware or indifferent to these findings. The focus of medicine in Singapore is on screening, early diagnosis, early and cost-effective treatment, not prevention. As such, there is widespread ignorance of well-established facts like the mid-adolescent shift in preference for later sleep times and its subsequent reversal in early adulthood.

TODAY | 29 May 2017

Do parents' support behaviours predict whether or not their children get sufficient sleep? A cross-sectional study

Pyper et al. found that on weekdays, enforcing rules about child bedtime was a significant positive predictor of children meeting sleep guidelines. Furthermore, the importance of children getting a good night's sleep, and the capacity of parents to help them do so, should be emphasized in public health efforts promoting healthy child development.

BMC Public Health | 24 May 2017

A big difference in students, after Nanyang Girls starts school later at 8.15am

"At the end of the day I would find myself losing focus and not really catching what the teacher was saying. But now, for my last lesson, I'll still be paying attention"

Channel NewsAsia | 10 May 2017

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