"Yet it is in our idleness, in our dreams, that the submerged truth sometimes comes to the top." - Virginia Woolf
Perhaps the most profound way to comprehend the realm of slumber and dreams is to delve into the enigmatic workings of the human brain. As the dawn of the twentieth century unfolded, a remarkable discovery emerged: the brain emitted electrical impulses. By the 1920s, scientists had honed the ability to quantify these cerebral waves. To capture these extraordinary readings, electrodes were meticulously affixed to distinct regions of the head, and the resulting impulses were meticulously transcribed onto electroencephalograms (EEGs), elegantly displayed on computer screens.
It becomes evident that, once you surrender to your nocturnal repose, a profound transformation befalls both your psyche and your corporeal vessel, distinct from your waking state. The demarcation between wakefulness and slumber is underscored by the relinquishing of conscious cognizance. As you commence your journey into the realm of dreams, scholars in the field posit that you traverse four stages of sleep, constituting a cyclical pattern that recurs up to four or five times within the span of eight hours of slumber.
During the inaugural stage, your body and mind gradually yield to relaxation. Heart and respiration rates decelerate, blood pressure undergoes a gentle decline, corporeal temperature experiences a modest descent, and your eyes engage in rhythmic lateral movements. You exist in a liminal state, neither fully ensconced in consciousness nor completely enveloped by unconsciousness. Should you encounter any perturbation, you might effortlessly reawaken. This phase of gradual descent into slumber is often referred to as the hypnagogic state. (Its counterpart, the hypnopompic state, materializes upon the brink of awakening.) During this phase, it is not uncommon to encounter phantasmagoric visions that dance before your eyes.
In the second stage, respiration and heart rate continue to decelerate, ocular movements persist, and you progressively disengage from extraneous auditory stimuli. However, it is only upon entering the third stage of sleep that you achieve profound somnolence, rendering the prospect of awakening increasingly arduous. Subsequently, you plunge into a profound slumber identified as non-rapid eye movement (NREM), during which your cerebral faculties are emancipated from the dominion of conscious cogitation. At this juncture, arousing you becomes a formidable task, and although instances of somnambulism or night terrors may arise, recollection of these episodes is seldom within your grasp. This phase of slow-wave sleep persists for approximately ninety minutes. Upon culmination of the fourth stage, you traverse the stages in reverse order—three, two, and one—ushering in a phase recognized as rapid eye movement (REM) sleep.
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