REM, NREM and dreaming
When asleep, two distinct patterns alternate throughout this time: NREM – a deep, dreamless non-rapid eye movement sleep, and REM – when rapid eye movement occurs and you dream.
When you fall asleep you drift into NREM, spending about 90 minutes sinking through four levels and back up again. This is broken by a 10-15 minute burst of REM during which time the body is almost completely immobile except for the rapid flickering of the eyeballs.
The brain is almost as active as it is when you are awake, and this is when dreams occur. It is thought that dreams are the brain’s way of sorting through information and experiences gathered when awake. This pattern of sleep repeats itself throughout the night, although the last REM before waking up can last up to an hour.
During an eight-hour night, dreams take up about two hours, and although everyone has them, not everybody can remember them. If you’re woken up in the middle of REM you are likely to remember the dream vividly. However, if you’re woken up just five minutes after REM you will have a vague recollection of a dream; after ten minutes you’re not likely to remember any of it.↑ Back to top