Professor Derk-Jan Dijk

Sleep is essential.

We should take sleep seriously, but not too seriously and not obsess about it.

The first 16 hours your brain is operating, you are alert, your mood is fine.

But then the night comes.

You become sleepier and sleepier.

Your biological clock will make you very sleepy until the very end of your natural sleep period.

At 9, 10, 11 o'clock in the morning of that second day,

You are less sleepy than at six or seven in the morning.

I think light sleep and REM sleep are as important as deep sleep.

And we all need all of it.

The sleep deprived person may become very impulsive.

There are many laboratory tests for gambling to see what kind of decisions the sleep deprived person is making.

They will always go for the high risk strategies where there may be short term benefits, but long term negative consequences.

Well, you haven't slept.

That's the problem.

Your cortex is hyper excited and it can't really function very well.

It can't regulate your responses.

Just to make it clear, being awake for three days is not safe.

You know, driving is a pretty boring task, and the effects of sleep deprivation are largest when you have to do a boring task.

If you have to do something difficult, the brain engages.