Sleep Paralysis: Biology Edition

If you've been researching what sleep paralysis is, it's probable that you've been overwhelmed by loads of jumbled information. Look no further than this post, as we'll be covering everything you need to know about sleep paralysis, medically speaking. 

Sleep paralysis actually fairly common across the world with 7.6% of the general population experiencing the phenomenon at least once in their lives. An episode of sleep paralysis is characterized by the following: upon sleeping or waking up, the individual experiences lack of mobility with an increasingly unsettling sensation accompanied by a crushing weight on the chest. While sleep paralysis has been most popular in the spiritual sense with demons and phantoms being blamed- the occurrence has many biological factors to it. 

To understand sleep paralysis, we first have to understand the science behind sleep. While sleep is continuously misperceived as the most unproductive part of our day, in reality, sleep actively functions to perform maintenance on our bodies; cleansing our brain of debris as noted in TIME Special Edition, The Science of Sleep. During sleep, neuronal activity is initiated in different stages which can be divided into non-REM and REM sleep. REM stands for Rapid Eye Movement and is known as the period of deep sleep in which vivid dreams occur. When you begin to dream, your brain enacts several functions: inhibiting motor neurons, eye movement and muscle twitches, and increased heart rate and blood pressure. 

Image Resource by Lumen Learning

Now, sleep paralysis occurs when your mind regains consciousness during REM sleep. This is why you're able to gain awareness of your surroundings, but are unable to move due to the inactivation of the motor neurons (such inhibition is for the purpose of preventing us from acting out our dreams). 

But what about the suffocating feeling and chest pressure? What about the dark glob in my room with red eyes? 

There are scientific explanations for the hag on your chest and other scary experiences one may undergo during this wrong timing. To understand this part of sleep paralysis, we have to explore brain structures and functions, most specifically: the parietal lobe, amygdala, and vestibular motor experience. 

The parietal lobe, behind the frontal and above the occipital lobe, is responsible for sensory input and language processing. It's been hypothesized that disturbances; multi-sensory input to the parietal lobe causes the feeling of an "intruder" in the room. When the individual actually sees a figure, it's called a hypnagogic (falling asleep) or hypnopompic (waking up) hallucination. The fear accompanied with this situation, as the unsettling sense of danger arises, is fault of the amygdala. Within the temporal lobe rests the almond shaped amygdala, playing a significant role in emotional behavior and motivation. 

As for the chest pressure and difficulty breathing part of the experience, called the "incubus" sensation, can also be blamed on our brain. As mentioned earlier, our breathing is more relaxed as we sleep and the neurons responsible for driving our movement are suppressed. Therefore, breathing difficulty occurs because the muscles in our airways are less active. 

See? Sleep paralysis isn't all about spooky spirits! 

While there is a disparity in information regarding causes of sleep paralysis, several studies have been conducted that reveal risk factors increasing susceptibility to having an episode. Such risk factors include: 

• stress
• trauma
• genetics
• illness
• irregular sleeping habits
• substance use
• anxiety

Therefore, sleep paralysis is most prevalent in students and psychiatric patients in which stress, anxiety, and lack of mental health are commonly seen. SP is also linked to bipolar disorder, narcolepsy, PTSD, and hypertension. 

That's a wrap for the science behind sleep paralysis! Can you believe how powerful your mind is to be able to generate such spooky sights as you sleep? 

Comment your thoughts down below!