Sleep, on a personal level, is incredibly frustrating. Wasting around seven to eight hours of every single day of our adult life on it seems like a colossal waste of time to me when there’s so much fun to be had while conscious, but it’s difficult to deny the vital health benefits that regular, unbroken, proper sleep – as elusive as that is – brings about.
Sleep deprivation (SD), whether intentional or inadvertent, takes them away, and it’s indubitable that you’ll miss them the moment they’re gone. So let’s journey, step-by-step, through what you enjoy when you sufficiently snooze, and what the myriad effects of a total loss of sleep may be, with the caveat that some of these effects remain decidedly enigmatic.
As is well known, you go through various phases of sleep, which form part of multiple cycles. When you engage in rapid eye movement (REM) sleep, you dream, and perhaps sleep-walk or talk, but this only makes up a small portion of your presumably nocturnal activities.
For the majority (75 percent or so) of your snoozing, you enter non-rapid eye movement (NREM) sleep, which comes in three distinct phases. During N1, you fluctuate between being awake and asleep, and not too much happens to you on a physiological level – although some of you may experience hypnic jerks, sudden muscle spasms that may shake you awake.
When N2 occurs, sleep begins in earnest, and you become unaware of your surroundings. Breathing and heart rate remain regular, but your core body temperature drops. N3, however – colloquially referred to as “deep sleep” – is where all the good stuff tends to happen.
As your blood pressure drops and stays low – which boosts cardiovascular health – your muscles relax and your breathing slows, and the blood supply to your muscles increases. Tissue growth and repairs are prioritized, and hormones vital to your proper functioning are released, including those that regulate feelings of hunger.
Your hippocampus, which deals with memory consolidation – among other things – shows plenty of electrical activity as you slumber. Although much remains unclear, recent studies have suggested that short-term memories acquired throughout the day appear to be progressively transferred to the cortex for long-term “storage” at night.
Something that falls away immediately after just one less night of sleep is those all-important cognitive reasoning and retention functions. From grammatical reasoning and spatial planning to memory recall activities, our abilities begin to drop off to varying degrees.