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September 6 - September 10, 2024
Perhaps you have also noticed a desire to eat more when you’re tired? This is no coincidence. Too little sleep swells concentrations of a hormone that makes you feel hungry while suppressing a companion hormone that otherwise signals food satisfaction.
should you attempt to diet but don’t get enough sleep while doing so, it is futile, since most of the weight you lose will come from lean body mass, not fat.
zeitgeber, from the German “time giver” or “synchronizer.”
humans likely evolved to co-sleep as families or even whole tribes, not alone or as couples.
the placebo effect is, after all, the most reliable effect in all of pharmacology.
For every day you are in a different time zone, your suprachiasmatic nucleus can only readjust by about one hour.
Caffeine has an average half-life of five to seven hours. Let’s say that you have a cup of coffee after your evening dinner, around 7:30 p.m. This means that by 1:30 a.m., 50 percent of that caffeine may still be active and circulating throughout your brain tissue. In other words, by 1:30 a.m., you’re only halfway to completing the job of cleansing your brain of the caffeine you drank after dinner.
For the entire time that caffeine is in your system, the sleepiness chemical it blocks (adenosine) nevertheless continues to build up.
Indeed, recent MRI scanning studies have found that there are individual parts of the brain that are up to 30 percent more active during REM sleep than when we are awake!
REM sleep has also been called paradoxical sleep: a brain that appears awake, yet a body that is clearly asleep.
It is often impossible to distinguish REM sleep from wakefulness using just elect...
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When it comes to information processing, think of the wake state principally as reception (experiencing and constantly learning the world around you), NREM sleep as reflection (storing and strengthening those raw ingredients of new facts and skills), and REM sleep as integration (interconnecting these raw ingredients with each other, with all past experiences,
Mere seconds before the dreaming phase begins, and for as long as that REM-sleep period lasts, you are completely paralyzed.
The brain paralyzes the body so the mind can dream safely.
If anything, the duck-billed platypus generates more of this kind of electrical REM-sleep
After all, absence of evidence is not evidence of absence.
In some species, many of the birds in a flock will sleep with both halves of the brain at the same time. How do they remain safe from threat? The answer is truly ingenious. The flock will first line up in a row. With the exception of the birds at each end of the line, the rest of the group will allow both halves of the brain to indulge in sleep. Those at the far left and right ends of the row aren’t so lucky. They will enter deep sleep with just one half of the brain (opposing in each), leaving the corresponding left and right eye of each bird wide open. In doing so, they provide full
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Individuals who are deliberately fasting will sleep less as the brain is tricked into thinking that food has suddenly become scarce.
In-flight, migrating birds will grab remarkably brief periods of sleep lasting only seconds in duration.
sleep in a biphasic pattern.
The practice of biphasic sleep is not cultural in origin, however. It is deeply biological. All humans, irrespective of culture or geographical location, have a genetically hardwired dip in alertness that occurs in the midafternoon hours.
I’m sure you’ve experienced this blanket of drowsiness that seems to take hold of you, midafternoon, as though your brain is heading toward an unusually early bedtime. Both you and the meeting attendees are falling prey to an evolutionarily imprinted lull in wakefulness that favors an afternoon nap, called the post-prandial alertness dip (from the Latin prandium, “meal”). This brief descent from high-degree wakefulness to low-level alertness reflects an innate drive to be asleep and napping in the afternoon, and not working. It appears to be a normal part of the daily rhythm of life.
modern society has divorced us from what should be a preordained arrangement of biphasic sleep—one that our genetic code nevertheless tries to rekindle every afternoon.
the true pattern of biphasic sleep—for which there is anthropological, biological, and genetic evidence, and which remains measurable in all human beings to date—is one consisting of a longer bout of continuous sleep at night, followed by a shorter midafternoon nap.
mortality risk of not napping increased by well over 60 percent.
when we are cleaved from the innate practice of biphasic sleep, our lives are shortened.
REM sleep increases our ability to recognize and therefore successfully navigate the kaleidoscope of socioemotional signals that are abundant in human culture, such as overt and covert facial expressions, major and minor bodily gestures, and even mass group behavior.
the coolheaded ability to regulate our emotions each day—a key to what we call emotional IQ—depends on getting sufficient REM sleep night after night.
Prior to birth, a human infant will spend almost all of its time in a sleep-like state, much of which resembles the REM-sleep
sedation is not sleep.
A bedroom temperature of around 65 degrees Fahrenheit (18.3°C) is a reasonable goal for the sleep of most people, assuming standard bedding and clothing.
Hot baths prior to bed can also induce 10 to 15 percent more deep NREM sleep in healthy adults.IV
No other species demonstrates this unnatural act of prematurely and artificially terminating sleep.V
sleep may have more of an influence on exercise than exercise has on sleep.
Keep in mind that 5:15 a.m. to a teenager is not the same as 5:15 a.m. to an adult.
Growing scientific evidence now supports the wisdom of later school start times.
