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Sleep paralysis episodes occur when your brain is in REM sleep but you are consciously awake. You are in transition typically from REM sleep to wakefulness, but you do not fully wake up. In fact. you retain some features of REM such as motor paralysis so you cannot move.
Even though you cannot move, you are nonetheless fully conscious. So your mind is awake but your body is not. It is still paralyzed, which is a normal component experience of REM. That experience usually frightens people.
But here is where the standard scientific account of sleep paralysis begins to break down. The "patient" with sleep paralysis is fully conscious of being unable to move and therefore begins to feel fear. As the fear builds, or so the story goes, the mind begins to spin stories (confabulate) to account for the fear and the paralysis, etc. The mind supposedly drifts in and out of REM and thus it starts to hallucinate.
One of the most consistent hallucinations reported by patients with sleep paralysis is that of the "intruder."
The intruder is usually described as a humanoid being who is sensed or seen or heard or all three. The patient somehow knows that the intruder is exceedingly evil and intends to harm the patient. The patient may hear voices or movements in the room and even feel the intruder touching the patient's body. The patient develops an almost tactile knowledge of the intruder. They may feel the breath of the intruder, watch it move, hear it speak, or smell the intruder.
For people who experience frequent sleep paralysis, the same intruder may appear over and over again, with the patient doing battle with the intruder over many months. Each time the intruder returns, he brings new psychological weapons to throw at the patient as if he remembered their last encounter. These battles can extract a physical toll on the patient, with some patients seeing welts, discolorations, or bruises where the intruder assaulted the patient during these violent encounters.
How is it possible to hallucinate in all five senses, when the mind is fully conscious? Perhaps these are not hallucinations at all. The mind is still in contact with reality during a sleep paralysis episode. The patient knows who he is, knows where he is, and knows what time it is. Indeed, the patient may attempt to call for help precisely because he realizes who and where he is and that a relative is sleeping nearby, for example. For standard definitions of hallucination, a patient must lose contact with reality but sleep paralysis patients do not. Therefore, they are probably not hallucinating.
In addition, it is not clear that the mind can be fully conscious and in REM sleep at the same time. In lucid dreaming, there is some awareness during REM but it is not an awareness of the outside world. Awareness is confined to the dream state. The lucid dreamer has no idea how many people are in the room in the real world where he is sleeping, for example. Therefore, the sleep paralysis patient's mind may not actually be in REM sleep.
Then, there is a problem of the "intruder." Most visual hallucinations are nowhere near as consistent and palpable as the "intruder." While you can see partially formed entities in dreams and in psychedelic states, none of these hallucinations are fully formed or consistent over time. On the contrary, the visual features of the intruder are reported with remarkable consistency by people of all ages and all cultural backgrounds and across all time epochs.
If the intruder was a hallucination, how would that remarkable consistency in appearance and behavior be possible? Nor do hallucinations come fully realized as the intruder does. As mentioned above, the intruder is experienced by all five senses of the patient. The patient can see, hear, feel/touch, smell, and interact with the intruder. The intruder is experienced with such reality and vividness that the patient is often left bruised, shaken and exhausted after an encounter. Many patients report that the intruder can often return over and over again, and with each return, evidence intellectual learning or growth. The intruder learns the patient's weaknesses and what psychological weapons will inflict the most harm on the patient and so forth. How can a mere hallucination possess these kinds of consistent personality attributes, and exhibit growth over time?
No. The standard hallucination-confabulation accounts of sleep paralysis won't work.
