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World Sleep Day

As today is the World Sleep Day, let us celebrate the benefits of good and healthy sleep.


Chronic sleep loss has recently been declared an epidemic by the Centre for Disease Control and Prevention (CDC) in the US. Notably, the problem is worse in our part of the world as some East Asia countries harbour some of the world’s most sleep-deprived populations.

Being a cognitive psychologist, Dr June Lo and her team at the Duke-NUS’ Neuroscience and Behavioural Disorders Programme, is interested in characterising the performance of sleep-restricted teens.

The Need for Sleep studies are a series of signature experiments conducted by Dr June and her colleagues designed to track adolescent participants’ cognitive performance over two simulated weeks of insufficient sleep on school nights and extended sleep on weekend nights. These studies revealed continuous deterioration in numerous performance measures, especially attention, with more nights of shortened sleep opportunities in the first week. Critically, some of these cognitive functions did not fully improve even after two weekend nights of 9-hour sleep. Thus, when sleep was reduced again the following school week, performance was worse and alarmingly deteriorated at an even faster rate. Although the cognitive deficits induced by insufficient sleep at night could be reduced to a certain extent with a 60 to 90-minute nap in the afternoon, these studies have consistently shown that the only route to stable and optimal performance was to sleep the recommended duration of 8-10 hours every night.

Aiming to create more sleep opportunities at night for teenage students, Dr June and her colleagues at the CCN collaborated with a secondary school in Singapore to delay its start time by 45 minutes in order to study changes in students’ sleep patterns and well-being. After the later school start time was implemented, the students enjoyed about 20 minutes more in bed on school nights, were less sleepy, had fewer problems staying awake during the daytime, and had better psychological well-being. All these benefits were sustained at the 9-month follow-up.

June and the other Principal Investigators at the CCN are planning for another Need for Sleep study as part of their efforts to find an optimal, yet feasible, sleep schedule for teens in Singapore.