It's pretty well known now that sleep is important for memory and learning, but what if I told you that when you were about to fall asleep - you might not remember it later?

In fact, remembering those times when you were awake or asleep over the course of the night is not as straightforward as it might seem.

To Sleep, Perchance to Wake

A recent study in the Journal of Sleep Research by Feige etl al., has shown that people generally perceive their wake time with just 45% accuracy.

Why?

One reason is that many people think they're awake when they were actually asleep, especially if they have any sleep-induced anxiety or sleep difficulties.

Sometimes this can happen when you're in REM sleep. Have you ever had one of those very realistic dreams in the morning when you think you've gotten out of bed, and then your alarm rings and wakes you up?

On the other side of the coin, you may think you're asleep when in reality, you're actually awake.

It's common to forget waking up in the middle of the night, especially if it was for a short period of time.  Studies (such as this one) have shown that short-term memories created within 3 minutes of falling asleep don't transition to long-term memories very well. 

Another study has even shown that some people think they were asleep during periods of wakefulness that lasted more than 2 hours over the course of the night

On a different, but related note, we often don't remember our dreams. Could this be associated with the difficulty to form long-term memories when we transition into and out of sleep? There's no clear-cut answer from sleep science for that one just yet, but it's a real possibility.

What does this mean for the typical sleeper?

1. The good news is that, whether you remember it or not, waking up from time to time during the night happens to everyone.
2. Since short-term memories don't translate well to long-term memories when you're falling asleep, cramming up to the last moment isn't going to help - set aside some time to wind down into a good night's rest.
3. If you're frustrated by the fact that you're not remembering your dreams, there's hope on this front - you can actually get better at remembering your dreams simply by writing them down in a dream diary right when you wake up each morning.

Are You Sleeping?

Do you find that you're waking up more or less than you thought?  I know it certainly happens to me sometimes.  Share your experience in the comments or on Zeo's Facebook wall.