Science - Human Spirit and Sleeping


REM (Rapid Eye Movement) sleep is a unique, active stage of sleep occurring roughly every 90 minutes, characterized by intense brain activity, vivid dreaming, increased heart rate, and temporary paralysis of voluntary muscles. It is crucial for memory consolidation, learning, mood regulation, and mental restoration. REM (Rapid Eye Movement) sleep is not considered "deep sleep." While both are critical, they are distinct, alternating stages of the sleep cycle with different functions. Deep sleep (NREM Stage 3) is for physical repair, while REM is for mental, emotional, and memory processing.



Key Characteristics of REM Sleep:


Brain Activity: Brain waves appear similar to those while awake, earning it the nickname "paradoxical sleep".

Muscle Atonia: Temporary paralysis of limb muscles occurs, preventing the acting out of dreams.

Rapid Eye Movements: Eyes move rapidly behind closed lids.

Physiological Changes: Heart rate, breathing, and blood pressure become faster and more irregular.

Dreaming: Most vivid, story-like dreams happen during this stage


Delta (less than 4Hz) and Theta (4-8 Hz) brain waves represent the slowest frequencies in the brain, associated with deep sleep, meditation, and subconscious, internal mental states. Delta waves drive restorative sleep, healing, and regeneration. Theta waves are dominant in light sleep, REM, deep meditation, and, when awake, are linked to creativity, imagination, and drifting thoughts. 



Neuroscience reports the following observations during sleep:


REM sleep

Theta and Delta brain waves

Paralysis of the body

Reduced sensory input


In conclusion, science does not recognize the human spirit as a separate entity but it reports: 

       

“The brain disconnects from the external world”



Qur'an - Human Spirit and Sleeping


ٱللَّهُ يَتَوَفَّى ٱلْأَنفُسَ حِينَ مَوْتِهَا وَٱلَّتِى لَمْ تَمُتْ فِى مَنَامِهَا فَيُمْسِكُ ٱلَّتِى

قَضَىٰ عَلَيْهَا ٱلْمَوْتَ وَيُرْسِلُ ٱلْأُخْرَىٰٓ إِلَىٰٓ أَجَلٍ مُّسَمًّى إِنَّ فِى ذَٰلِكَ لَـَٔايَـٰتٍ لِّقَوْمٍ يَتَفَكَّرُونَ


Allah takes the souls away fully at the time of their death, and as for the one that has not yet died,

He takes it away during their sleep.

Then, He keeps hold of the soul for whom He has decreed death, and He sends back the others until a fixed term.

There are surely signs in this matter for people who reflect 39:42


The above statement about the soul leaving the body during sleep is matched by the scientific report of brain disconnecting from the external world. Note that science has not reached a point in recognizing the soul as a separate entity.


There are some narrations from Prophet Muhammad (PBUH) and some sermons (e.g. Sermon 221) from Imam Ali ibn Talib (AS) discussing where the soul goes after we die. The discussion also includes when the soul is taken during sleep.


When the soul is taken during sleep, some people are:


  • Shown Signs of Allah
  • Warned
  • Comforted
  • Tested
  • Taught


During sleep, the sensory filter is off, the ego is quiet, the conscious mind is silenced, and the spirit perceives directly.

Additionally, time collapses, distance disappear, fear and happiness feel absolute, and the Truth feels undeniable. You’re closer to the realm of afterlife than you are while awake.


The soul is created in the other world (عالَم اَمر ) by the Command (أَمْر ) of the Creator while gender, age, dimension, and time do not apply to it. It would be naive to consider that everything must be made up of earthly elements (with dimensions and weight). Both the body and spirit, created separately by Allah (SWT), are destined for each other on Earth. Many verses describe that human body is made up of ordinary elements found in water and soil (e.g., 15:28, 15:33, 22:5, 23:12, 25:54, 32:7, 37:11, 55:14). However, the human spirit is described as the main identity of humans because of its immense potential to become greater than the angels. The body is only a medium to accompany the spirit in this world. You may think of the body and spirit as companions of each other in this world. After death, the body and spirit separate. The spirit continues its journey to the realm of Barzakh and remains there until Judgement Day.