During my night shifts it sometimes happens – when I’m staring straight ahead – that I have no sense of time and space. However I did not sleep as I am 100% sure that my eyes were open. Forced wakefulness and fatigue certainly have something to do with this. I notice this when I realize that suddenly the time has flown by less than fifteen minutes. But is it possible that with my eyes open (even if it is 5 to 10 minutes) I can get away from the world for a while? Is this still called sleep or is it something else?
Answer
Hi Jo,
You can tell whether someone is sleeping by the brain waves of an electroencephalogram (EEG). The waves slow down as you doze off. Based on what those waves look like, five stages of sleep are distinguished in which the person sleeps deeper and deeper. Already in the first stage, the eyes normally close. There is such a thing as a microsleep, where the eyes are open, but that only lasts for a few seconds and not fifteen minutes as you indicate.
You are probably talking about differences in attention. With selective attention you concentrate on one thing while you want to exclude disturbing environmental influences. If you don’t, you may not be able to read this sentence and be distracted by noises around you. If you are fatigued or have to perform a vigilance task (which is a task that requires you to do something infrequently at frequent intervals such as looking at a surveillance camera) your brain may go into ‘autopilot’ mode and you function based on your experience. You then start daydreaming and before you know it you are a page further in a book without having read anything consciously. You can also sometimes have this when you drive a car and suddenly do not know that you have passed a traffic light.
This all happens especially when you are tired. Getting enough sleep (in your bed) could therefore help.
Answered by
Dr Lise Van der Haegen
Cognitive Psychology, Neurosciences (Ghent University), Science Communication (Artevelde University College Ghent)
http://www.arteveldehs.be
.