non-REM and REM sleep and dreaming Flashcards
There are five distinct stages of sleep which are grouped into two types what are they called?
non-REM and REM sleep
What does non-REM refer to?
Non-REM refers to stages 1-4
Because stage 5 is so different to the others, what is this referred to as?
REM sleep
The changes from one stage to the next are observed by?
measuring brain waves
Stage 1
This is the lightest stage of sleep. You are very easily awoken in this stage by external stimuli and will still be aware of your surroundings. This stage will only last between 5-10 minutes and will feel as if you are ‘drifting off.’
Stage 2
This stage lasts around 20 minutes. There are physiological differences in this stage – body temperature drops and heart rate slows. Your awareness of the outside world fades away in this stage. Important brainwaves known as sleep spindles occur during this stage. Sleep spindles work to block external stimuli from waking the sleeper up.
Stages 3 and 4
Sleep researchers now group stage 3 and 4 together as there is very little distinction between them. During these stages you will be extremely unresponsive to the outside environment and will be hard to wake up. This is the deepest stage of sleep. If you were woken in this stage, you would feel very groggy.
There are dramatic biological changes when we enter REM sleep what is this known as?
This stage is known as REM sleep due to the rapid eye movement that occurs.
Your eyes will rapidly move from side to side beneath your eyelids. Your body, however, does not move and is temporarily paralysed what is this known as?
This is known as atonia. This likely occurs to stop us from acting out our dreams, in order to protect ourselves and those we sleep next to
The brainwaves observed during REM sleep are very similar to when we are awake. What is this also the stage of?
The brainwaves observed during REM sleep are very similar to when we are awake. This is also the stage of sleep when we dream.
