Why We Sleep by Matthew Walker Flashcards
(106 cards)
1
Q
What is the relationship between sleep duration and lifespan?
A
The shorter your sleep, the shorter your life span.
2
Q
What is the most effective thing we can do to reset our brain and body health each day?
A
Sleep.
3
Q
What is the circadian rhythm?
A
One of two factors determining wake and sleep.
4
Q
What role does melatonin play in sleep?
A
Helps regulate the timing of when sleep occurs by signalling darkness.
5
Q
What is sleep pressure?
A
Caused by a buildup of the chemical adenosine in your brain.
6
Q
How does caffeine affect sleepiness?
A
Blocks the receptors that adenosine affects.
7
Q
How long does it take for caffeine to start working?
A
About 30 minutes.
8
Q
What factors influence how people process caffeine?
A
Some people process caffeine faster than others, and we get less efficient as we age.
9
Q
What are three questions to identify sleep deficiency?
A
- If you didn’t set an alarm clock, would you wake up on time?
- Do you find yourself re-reading things?
- Can you function optimally before noon without caffeine?
10
Q
What are the three states of information processing related to sleep?
A
- Wake state: reception
- NREM sleep: reflection
- REM sleep: integration
11
Q
What is the purpose of eliminating muscle activity during REM sleep?
A
To prevent acting out your dream experience.
12
Q
What is one of the most important take-homes of this book regarding sleep?
A
Humans can never sleep back what has been previously lost.
This concept will be elaborated in chapters 7 and 8.
13
Q
What sleep pattern do most adults in developed nations currently follow?
A
Monophasic pattern.
This pattern involves one long bout of slumber at night.
14
Q
What is the average duration of sleep for adults in developed nations?
A
Less than seven hours.
15
Q
What sleep pattern is observed in hunter-gatherer tribes like the Gabra and San?
A
Biphasic pattern.
This includes a longer sleep period at night and an afternoon nap.
16
Q
How many hours do the Gabra and San tribes typically spend in bed at night?
A
Seven to eight hours.
17
Q
What is the typical duration of the afternoon nap taken by the Gabra and San tribes?
A
Thirty to sixty minutes.
18
Q
What is a consequence of being cleaved from the innate practice of biphasic sleep?
A
Lives are shortened.
19
Q
In which Greek enclave is the practice of siestas still intact?
A
Island of Ikaria.
20
Q
How much more likely are men in Ikaria to reach the age of ninety compared to American males?
A
Nearly four times as likely.
21
Q
What is the primary function of REM sleep?
A
Recalibrates and fine-tunes the emotional circuits of the human brain.
22
Q
What effect does REM sleep have on creativity?
A
It fuels creativity.
23
Q
What is the significance of the increasing intensity and richness of REM sleep over millennia?
A
It could lead to rapid and exponential scaling of emotional brain recalibration.
24
Q
What is one of the most powerful suppressors of REM sleep?
A
Alcohol
25
What precedes cognitive and developmental milestones in childhood?
Changes in deep NREM sleep
26
What implication is suggested about deep sleep in childhood development?
Deep sleep may be a driving force of brain maturation
27
What is a common misconception about older adults and sleep?
That older adults simply need less sleep
28
Do older adults need as much sleep as they did in midlife?
Yes, they need just as much sleep
29
What happens to the quantity and quality of deep NREM sleep as one enters their fourth decade of life?
There is a palpable reduction
30
What is a hallmark of altered sleep in older adults?
Sleep fragmentation
31
What does sleep fragmentation lead to in older individuals?
Reduction in sleep efficiency
32
What is defined as the percent of time you were asleep while in bed?
Sleep efficiency
33
What sleep efficiency percentage do healthy teenagers typically enjoy?
About 95 percent
34
What is considered good-quality sleep by most sleep doctors?
Sleep efficiency of 90 percent or above
35
What consequences can arise from chronically disrupted sleep?
* Physical ailments
* Mental health instability
* Reduced alertness
* Impaired memory
36
What change in sleep timing is commonly experienced by seniors?
Regression in sleep timing leading to earlier bedtimes
37
What is one of the most impressive advantages of sleep for the brain?
Memory
## Footnote
Sleep acts as a memory aid both before and after learning.
38
How does sleep help with memory after learning?
Cements memories and prevents forgetting
## Footnote
Sleep reinforces newly formed memories.
39
What type of sleep is responsible for overnight motor-skill enhancement?
Stage 2 NREM sleep
## Footnote
Particularly during the last two hours of an eight-hour sleep.
40
What happens when you obtain less than eight hours of sleep a night?
Time to physical exhaustion drops by 10 to 30 percent
## Footnote
Aerobic output is significantly reduced as well.
41
List some impairments observed with less than six hours of sleep.
* Decreased limb extension force
* Reduced vertical jump height
* Decreased peak and sustained muscle strength
## Footnote
These impairments affect overall physical performance.
42
What cardiovascular and metabolic issues arise from sleep loss?
* Faster rates of lactic acid buildup
* Reductions in blood oxygen saturation
* Increases in blood carbon dioxide
## Footnote
Sleep loss hampers the body's physiological capabilities.
43
How does sleep loss affect the body's ability to cool itself?
Impaired cooling through sweating
## Footnote
This is critical for peak performance during physical exertion.
44
What is the importance of post-performance sleep?
* Accelerates physical recovery from inflammation
* Stimulates muscle repair
* Helps restock cellular energy in glucose and glycogen
## Footnote
Essential for recovery after athletic performance.
45
What is arguably the most remarkable benefit of sleep for memory?
Creativity
## Footnote
Sleep enhances creative problem-solving and idea generation.
46
What are some neurological and psychiatric conditions linked to sleep loss?
* Alzheimer’s disease
* Anxiety
* Depression
* Bipolar disorder
* Suicide
* Stroke
* Chronic pain
## Footnote
Sleep loss affects both brain function and physiological systems, contributing to numerous health issues.
47
What physiological disorders can result from sleep loss?
* Cancer
* Diabetes
* Heart attacks
* Infertility
* Weight gain
* Obesity
* Immune deficiency
## Footnote
Sleep deprivation has a broad impact on health, affecting nearly every system in the body.
48
How does sleep deprivation affect concentration?
It leads to significant failures in concentration, particularly dangerous in drowsy driving situations.
49
What is the consequence of fatigue-related errors in driving in the US?
Every hour, someone dies in a traffic accident due to fatigue-related errors.
50
How many hours of sleep do humans need each night to maintain cognitive performance?
More than seven hours.
51
What happens to the brain after ten days of only seven hours of sleep?
It becomes as dysfunctional as if it had gone without sleep for twenty-four hours.
52
How many nights of recovery sleep are needed to restore performance after a week of short sleeping?
Three full nights of recovery sleep.
53
True or False: The human mind can accurately sense how sleep-deprived it is.
False.
54
Can naps replace the need for sleep?
No, there is no scientific evidence that naps, drugs, or psychological willpower can replace sleep.
55
What temporary effects can power naps and caffeine have?
They may momentarily increase basic concentration under conditions of sleep deprivation.
56
What brain functions cannot be salvaged by naps or caffeine?
* Learning
* Memory
* Emotional stability
* Complex reasoning
* Decision-making
## Footnote
These higher-level cognitive functions require adequate sleep.
57
What is a 'sleepless elite'?
A rare group of individuals who can function on six hours of sleep with minimal impairment.
58
What genetic factor is related to the 'sleepless elite'?
A sub-variant of the gene called BHLHE41.
59
What emotional issues can arise from sleep deprivation?
Many emotional and psychiatric problems can occur under sleep deprivation.
60
What is the impact of not sleeping after learning on memory consolidation?
You lose the chance to consolidate those memories.
61
How is sleep recognized in relation to Alzheimer’s disease?
A lack of sleep is recognized as a key lifestyle factor determining the risk of developing Alzheimer’s disease.
62
What potential does sleep have regarding Alzheimer's disease?
It represents a candidate for hope in diagnosis, prevention, and therapeutics.
63
What correlates most with our dreams?
Emotional concerns
## Footnote
Emotional concerns have been found to be the primary correlates with dreams.
64
What is the significance of REM sleep in relation to anxiety?
It is the only time when the brain is devoid of noradrenaline
## Footnote
Noradrenaline, also known as norepinephrine, triggers anxiety.
65
What chemical is the brain equivalent to adrenaline?
Noradrenaline
## Footnote
Noradrenaline is also referred to as norepinephrine.
66
What is the role of certain brain regions during dreaming?
To read and decode emotional signals, especially faces
## Footnote
These brain regions are recalibrated during REM sleep.
67
What happens to perceptions of the outside world when the brain lacks REM sleep?
It becomes more threatening and aversive, untruthfully
## Footnote
The lack of REM sleep distorts the perception of reality.
68
What role does deep NREM sleep play in memory?
It strengthens individual memories
## Footnote
Deep NREM sleep is crucial for memory consolidation.
69
What benefit does REM sleep provide in terms of memory?
It fuses and blends memories in abstract and novel ways
## Footnote
REM sleep complements the memory strengthening of deep NREM sleep.
70
Fill in the blank: REM sleep offers the masterful benefit of _______.
fusing and blending memories
## Footnote
This process occurs in abstract and highly novel ways during REM sleep.
71
What is one of the most pressing medical issues facing modern society?
Insomnia
## Footnote
Insomnia is often underrecognized and its burden overlooked.
72
Name one factor that has changed how much and how well we sleep.
Constant electric light
## Footnote
Other factors include regularized temperature, caffeine, alcohol, and a legacy of punching time cards.
73
How much does reading on an iPad suppress melatonin release compared to reading a printed book?
Over 50 percent
## Footnote
iPad reading can delay the rise of melatonin by up to three hours.
74
What is a recommended solution to limit exposure to artificial evening light?
Create lowered, dim light in evening rooms
## Footnote
Avoid powerful overhead lights and consider wearing yellow-tinted glasses.
75
What is the ideal bedroom temperature for most people to sleep well?
Around 65 degrees Fahrenheit (18.3°C)
## Footnote
This temperature helps dictate the thermal envelope around the body at night.
76
What are two ways alcohol affects sleep?
* Fragments sleep with brief awakenings
* Suppresses REM sleep
## Footnote
Alcohol's sedating effect is not restorative and can disrupt sleep quality.
77
What is the best recommendation regarding alcohol consumption and sleep?
Abstinence
## Footnote
The evidence strongly indicates that alcohol disrupts sleep.
78
What physiological change occurs when taking a hot bath before bed?
Blood is invited to the surface of the skin
## Footnote
This leads to a drop in core body temperature, which helps with falling asleep.
79
Fill in the blank: A hot bath prior to bed can induce _______ more deep NREM sleep in healthy adults.
10 to 15 percent
## Footnote
This effect is due to the drop in core body temperature after bathing.
80
True or False: Maintaining complete darkness throughout the night is critical for sleep quality.
True
## Footnote
Blackout curtains are an effective solution for achieving darkness at night.
81
Do sleeping medications induce natural sleep?
No, they do not induce natural sleep.
## Footnote
Sleeping medications can disrupt the natural sleep cycle.
82
How much more likely are those taking sleeping pills to die compared to non-users?
4.6 times more likely.
## Footnote
This statistic is based on a study over a two-and-a-half-year period.
83
What defines heavy users of sleeping pills in the study?
Taking more than 132 pills per year.
## Footnote
Heavy users had a mortality risk 5.3 times higher than non-users.
84
What is the mortality risk for occasional users of sleeping pills?
3.6 times more likely to die than non-users.
## Footnote
Occasional users were defined as taking just eighteen pills per year.
85
What is the first-line treatment for insomnia according to the medical community?
Cognitive behavioral therapy for insomnia (CBT-I).
## Footnote
CBT-I is effective in breaking bad sleep habits.
86
What are some obvious methods included in CBT-I?
* Reducing caffeine and alcohol intake
* Removing screen technology from the bedroom
* Maintaining a cool bedroom
## Footnote
These methods help create a conducive sleep environment.
87
List two key practices recommended for better sleep hygiene.
* Establish a regular bedtime and wake-up time
* Go to bed only when sleepy
## Footnote
Consistency in sleep schedule is crucial for improving sleep quality.
88
What should a person do if they cannot fall asleep after a significant time in bed?
Get out of bed and do something quiet and relaxing.
## Footnote
This helps avoid frustration and anxiety related to not sleeping.
89
What is the single most effective way to improve sleep, according to the text?
Going to bed and waking up at the same time every day.
## Footnote
This practice is emphasized as crucial for good sleep hygiene.
90
How does physical activity relate to sleep quality?
Increased physical activity leads to better sleep quality.
## Footnote
There is a bidirectional relationship between sleep and physical activity.
91
What caution is advised regarding exercising before bed?
Avoid exercising right before bed as it can raise body temperature.
## Footnote
A high body temperature can hinder the ability to fall asleep.
92
What is the recommended time gap between exercising and bedtime?
At least two to three hours.
## Footnote
This allows the body to cool down for better sleep initiation.
93
Why is REM sleep critical?
REM (Rapid Eye Movement) sleep is critical for cognitive function and emotional regulation.
94
What are the two steps of logic proposed for addressing the issue of deficient sleep?
1. Understand why the problem persists
2. Develop a structured model for effecting change
## Footnote
This approach aims to tackle sleep deficiency at multiple levels.
95
What is the first tip for healthy sleep?
Stick to a sleep schedule
## Footnote
A consistent sleep schedule helps regulate the body's internal clock.
96
How long should you exercise on most days for better sleep?
At least thirty minutes
## Footnote
Exercise should not be done later than two to three hours before bedtime.
97
What substances should be avoided to promote healthy sleep?
Caffeine and nicotine
## Footnote
Both substances can disrupt sleep patterns.
98
When should alcoholic drinks be avoided?
Before bed
## Footnote
Alcohol can interfere with sleep quality.
99
What types of meals should be avoided late at night?
Large meals and beverages
## Footnote
Eating late can cause discomfort and disrupt sleep.
100
When is the latest time to take naps for healthy sleep?
3 p.m.
## Footnote
Napping too late in the day can interfere with nighttime sleep.
101
What should be included in your bedtime ritual?
A relaxing activity
## Footnote
Activities like reading or listening to music help unwind before sleep.
102
What can be done to relax before bed?
Take a hot bath
## Footnote
A hot bath can help signal to the body that it's time to wind down.
103
What characteristics should a bedroom have for healthy sleep?
Dark, cool, and gadget-free
## Footnote
These conditions promote better sleep quality.
104
How much natural sunlight exposure is recommended each day?
At least thirty minutes
## Footnote
Sunlight exposure helps regulate daily sleep patterns.
105
What should you do if you find yourself lying in bed awake?
Don’t lie in bed awake
## Footnote
Get up and do a quiet activity until you feel sleepy.
106
