Ever woken up but couldn't move? They call it, "Sleep Paralysis"

This situation doesn't happen often and only to some people. It is a very weird experience for many people. Almost ghostly... but it all has a perfect reason. A reason which I am going to discuss on this post...

Sleep paralysis is the inability to move or speak as if you are frozen. Your breathing and eye movement is at minimum. You may be able to feel as if someone is sitting on you. You feel awake but cannot move or speak. You might even feel as if you are being choked or see dark shadows and hear strange noises. Our ancestors thought this situation was caused by evil spirits. But modern technology suggests the contrary, it is a hereditary disorder meaning that it is passed down from one parent to the offspring.

Sleep paralysis is due to the mis-transmission of neural signal in the brain (a bit like cars going on wrong lanes). While sleeping, our brain actually sends signals to inhibit (stop) movements (muscle contraction) in our body. If a person regains consciousness before the brain can send signals to activate the muscle movements, the person is unable to move.



We must understand what happens while we're sleeping to know what actually causes sleep paralysis.

While sleeping, our brain switches alternatively from REM (Random Eye Movement) sleep and NREM (Non Random Eye Movement) sleep.

While in the NREM phase of our sleep, we are able to make little movements such as change position, scratch our nose etc... (Sleep walking occurs at this stage)

On the other hand, in REM sleep we are having dreams and our eyes move rapidly. Experts say that this is due to the reason that we are actually "looking" at whats happening in our dreams. It is this stage that our body undergoes total paralysis. The stage where the brain paralyzes our body is called, "non reciprocal flaccid paralysis". The paralysis during our REM sleep is done my the post-synaptic inhibition of motor neurons. This happens to prevent movement while dreaming otherwise we might start acting out what we're doing in our dreams such as, punching things if we're dreaming of fights or start singing if we're singing in our dreams.


Sleep paralysis is experienced when you wake up during the REM stage of sleep and may last for a few minutes. During this time, people often feel mortal fear or extreme panic therefore the brain generates and releases internal visual or auditory signals producing hallucinations. Hallucinations can also occur if half of your brain wakes up but the other half is still dreaming in REM mode so the person might see and hear things produced by the dreams.