What you didn't know about the verges of sleep

[00:00.93] How long does it take you to fall asleep?

[00:05.18] Are you out like a light as soon as your head hits the pillow, or does it take you more than a little time to doze off?

[00:15.27] If the average night’s sleep is eight hours, or a third of a day, then it means we spend around one third of our lives in this dormant state.

[00:27.22] Science already has reams of data on the brain’s activity during sleep itself.

[00:33.86] Now, an international group of researchers at the University of Cambridge are researching that dopey state we all go through between wide awake and fast asleep.

[00:47.14] This transitional period usually lasts between five and 20 minutes, says Sridhar Rajan Jagannathan, one of Cambridge’s Gates Scholars.

[00:59.63] However, people exhibit a variety of behaviour within this time.

[01:06.27] For some, going to the land of nod is a smooth, quick journey, while others have more difficulty.

[01:15.83] They “begin to get drowsy” and then snap out of it “back to alertness” he says.

[01:24.07] The aim of the research is to find out how this pre-sleep phase, when the eyes glaze, the attention wanders and the mind is lulled, could be linked to accidents and dangerous mistakes.

[01:40.80] This could happen during the day while at work. “If you’re doing some boring task, you might be drowsy in this period.

[01:51.16] Small drift-offs can cause big problems,” says Mr Jangannathan.

[01:56.47] This is not just connected to safety concerns with driving, for example, but any task where concentration and decision making are important.

[02:09.75] There are positive sides to this hypnagogic period too. Some experts think there is a connection to creativity and imagination.

[02:20.91] This is caused by a reduction in your inhibitions, which makes you more creative.

[02:27.28] You have more freedom to express yourself, and you’re more willing to make mistakes.

[02:33.13] It certainly seems to support the old adage of sleeping on it to solve a problem.

[02:40.03] Ultimately, there are hopes that research into brain activity during falling asleep and waking might help stroke victims who are trying to regain lost physical functions.

[02:53.05] That could well be a pipe dream.

[02:55.97] There are also research efforts underway to find ways to warn of the onset of sleep, identifying changes in eye movements or brain activity.

[03:06.33] These could have practical applications for tired people operating heavy machinery and may help ensure that when it comes to accidents, we’re not caught napping.