Why We Sleep

Metadata

• Author: Matthew Walker
• Full Title: Why We Sleep
• Category: #type/books

Highlights

• “a ruffled mind makes a restless pillow,” (Location 95)
• It was in 1729 when French geophysicist Jean-Jacques d’Ortous de Mairan discovered the very first evidence that plants generate their own internal time. (Location 258)
• the circadian rhythm—that is, one that is approximately, or around, one day in length, and not precisely one day. (Location 303)
• Any signal that the brain uses for the purpose of clock resetting is termed a zeitgeber, from the German “time giver” or “synchronizer.” (Location 321)

New highlights added September 8, 2021 at 10:26 PM

• For every day you are in a different time zone, your suprachiasmatic nucleus can only readjust by about one hour. (Location 434)
• The consumption of caffeine represents one of the longest and largest unsupervised drug studies ever conducted on the human race, perhaps rivaled only by alcohol, and it continues to this day. (Location 474)
• Caffeine works by successfully battling with adenosine for the privilege of latching on to adenosine welcome sites—or receptors—in the brain. (Location 476)
• 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. (Location 483)
• de-caffeinated does not mean non-caffeinated. (Location 493)
• Depending on the decaffeination method and the bean that is used, one cup of decaf can have between 3 to as high as 10 percent of the dose of a regular cup of coffee. (Location 493)
• Aging also alters the speed of caffeine clearance: the older we are, the longer it takes our brain and body to remove caffeine, and thus the more sensitive we become in later life to caffeine’s sleep-disrupting influence. (Location 501)

New highlights added September 9, 2021 at 7:02 PM

• First, after waking up in the morning, could you fall back asleep at ten or eleven a.m.? If the answer is “yes,” you are likely not getting sufficient sleep quantity and/or quality. (Location 594)
• Second, can you function optimally without caffeine before noon? If the answer is “no,” then you are most likely self-medicating your state of chronic sleep deprivation. (Location 595)

New highlights added September 11, 2021 at 9:08 AM

• 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, and, in doing so, building an ever more accurate model of how the world works, including innovative insights and problem-solving abilities). (Location 870)

New highlights added September 13, 2021 at 4:40 PM

• 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. (Location 1134)

New highlights added September 21, 2021 at 10:24 AM

• Alcohol is one of the most powerful suppressors of REM sleep that we know of. (Location 1346)

Why We Sleep

Metadata

• Author: Matthew Walker
• Full Title: Why We Sleep
• Category: #type/books

Highlights

• “a ruffled mind makes a restless pillow,” (Location 95)
• It was in 1729 when French geophysicist Jean-Jacques d’Ortous de Mairan discovered the very first evidence that plants generate their own internal time. (Location 258)
• the circadian rhythm—that is, one that is approximately, or around, one day in length, and not precisely one day. (Location 303)
• Any signal that the brain uses for the purpose of clock resetting is termed a zeitgeber, from the German “time giver” or “synchronizer.” (Location 321)
• For every day you are in a different time zone, your suprachiasmatic nucleus can only readjust by about one hour. (Location 434)
• The consumption of caffeine represents one of the longest and largest unsupervised drug studies ever conducted on the human race, perhaps rivaled only by alcohol, and it continues to this day. (Location 474)
• Caffeine works by successfully battling with adenosine for the privilege of latching on to adenosine welcome sites—or receptors—in the brain. (Location 476)
• 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. (Location 483)
• de-caffeinated does not mean non-caffeinated. (Location 493)
• Depending on the decaffeination method and the bean that is used, one cup of decaf can have between 3 to as high as 10 percent of the dose of a regular cup of coffee. (Location 493)
• Aging also alters the speed of caffeine clearance: the older we are, the longer it takes our brain and body to remove caffeine, and thus the more sensitive we become in later life to caffeine’s sleep-disrupting influence. (Location 501)
• First, after waking up in the morning, could you fall back asleep at ten or eleven a.m.? If the answer is “yes,” you are likely not getting sufficient sleep quantity and/or quality. (Location 594)
• Second, can you function optimally without caffeine before noon? If the answer is “no,” then you are most likely self-medicating your state of chronic sleep deprivation. (Location 595)
• 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, and, in doing so, building an ever more accurate model of how the world works, including innovative insights and problem-solving abilities). (Location 870)
• 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. (Location 1134)
• Alcohol is one of the most powerful suppressors of REM sleep that we know of. (Location 1346)