Sometimes waking up is hard and you just want to hit the snooze button on the alarm, and sometimes you feel refreshed. Maybe the snooze button doesn't help and you still feel groggy. Researchers in India think they now know why that happens: your alarm clock is out of sync with your sleep cycle. And they think the problem can be fixed.
Sleep has a cycle that lasts about 90 minutes and involves four stages, two of which are lighter and easier to wake from. If you wake somebody up during the light periods they feel more refreshed, whereas doing so during deep sleep produces the urge to turn over and pull the blanket over your head. By monitoring the stages of sleep a person is in, an alarm clock could be set to only go off at times when a person is sleeping lightly.
This is more than just a comfort exercise: sleep is important to maintaining cognitive function and overall health. (In fact, depriving someone of sleep is classified as torture in many countries). Even though the precise functions of sleep are still unknown, it’s clear that a lot of adults in the industrialized world aren’t getting enough of it.
The team put electrodes on a subject’s head to monitor their brain activity with an EEG, and linked the output to the alarm clock. That isn’t so convenient, but a headband could be set up that would be worn whilst in bed. The electrodes could even be wireless.
In tests, the alarm time was set and the monitoring process began 90 seconds before the alarm was set to go off. An onboard computer determined what stage of sleep the subject was in during the monitoring period. If they were in the third or fourth stages of sleep, (the deepest), the alarm was "snoozed.” If they were in the first or second stages of sleep, the alarm went off.
With a little tweaking one could even have an alarm clock and computer record sleep activity all night, over time, and from there determine if the alarm time is lining up well with the first or second sleep stage. This would allow someone to adjust the alarm time to better coincide with stage one or two sleep. That might mean getting up earlier -– by as much as 45 minutes -– but it would probably feel a lot better.