“Dreaming provides a unique suite of benefits for all species fortunate enough to experience it.” – pg. 7
“The brain melds past and present knowledge, inspiring creativity.” – pg. 7
Sleep Pressure – When the chemical adenosine builds up in your brain. The longer you are awake, the more adenosine will accumulate. – pg. 26
“NREM sleep is one of the most epic displays of neural collaboration that we know of. Through an astonishing act of self-organization, many thousands of brain cells have all decided to unite and ‘sing,’ or fire, in time. Every time I watch this stunning act of neural synchrony occurring at night in my own research laboratory, I am humbled: sleep is truly an object of awe.” – pg. 49
REM sleep – Has also been called paradoxical sleep: a brain that appears awake, yet a body that is clearly asleep. It recalibrates and fine-tunes the emotional circuits of the human brain. It also fuels creativity: acting as an electrical fertilizer during critical phases of early life. REM sleep brainwaves are chaotic and desynchronized: showing a vivacious and healthy form of electrical activity. It is often impossible to distinguish REM sleep from wakefulness using just electrical brainwave activity. REM sleep is what stands between rationality and insanity. – pg. 51, 73-78, 82, 309
“Partially aquatic mammals, they split their time between land and sea. When on land, they have both NREM sleep and REM sleep […]. But when they enter the ocean, they stop having REM sleep almost entirely.” – pg. 60
Unihemispheric – The ability to sleep with half a brain at a time. Dolphins and whales exhibit this, as well as birds when alone. When in a flock, birds will line up in a row – and 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. At some point, the two end-guards will stand up, rotate 180 degrees, and sit back down, allowing the other side of their respective brains to enter deep sleep. – pg. 63-64
“REM sleep is strangely immune to being split across sides of the brain.” – pg. 65
“In flight, migrating birds will grab remarkably brief periods of sleep lasting only seconds in duration.” – pg. 66
“Biologically, it is as if the day and night are far less light and dark, respectively, for autistic individuals.” – pg. 80
“Alcohol is one of the most powerful suppressors of REM sleep that we know of.” – pg. 81
“The proportion of REM sleep decreases in early childhood, while the proportion of NREW sleep actually increases.” – pg. 85
“Deep sleep may be a driving force of brain maturation, not the other way around.” – pg. 89
“Most of us do not have a good sense of our electrical sleep quality.” – pg. 95
Targeted Memory Reactivation – Selectively enhancing only the individual memories that you want to keep. Before going to bed, you review the learning experiences of the day, choosing only the memories from the menu list that you would like improved. – pg. 118
“Sleep [is] an active brain state, one in which we may review and even strengthen those things we have previously learned. […] In other words, your brain will continue to improve skill memories in the absence of any further practice.” – pg. 124-125
In one study, the accruing performance impairment (caused by only obtaining 4-6 hours of sleep) showed no signs of leveling out. Performance deterioration would continue to build up over weeks or months. – pg. 137
“The heady cocktail of sleep loss and alcohol was not additive [when it came to performance deterioration], but instead multiplicative.” – pg. 140
In another study, sleep-deprived participants showed a 60% amplification in emotional reactivity. This was seen when measuring activity of the Amygdala: the brain structure linked to fight-or-flight, also acting as a hot spot for triggering anger and rage. – pg. 146
“Lack of sleep is a causal trigger of a psychiatric episode of mania or depression.” – pg. 150
Decreased attractiveness due to being sleep-deprived is a physical expression of underlying biology that alters your chances of pair bonding and thus reproduction. – pg. 180
“Emotional regions of the brain are up to 30% more active in REM sleep compared to when we are awake.” – pg. 195
Latent Content – Repressed desires, or unconscious wishes that had not been fulfilled, according to Freud. – pg. 200
Manifest Content – Camouflaged wishes and desires that are unrecognizable to the dreamer. – pg. 200
“A meaningful, psychologically healthy life is an examined one.” – pg. 203
Dreams are not a wholesale replay of our waking lives. However, between 35-55% of emotional themes and concerns that study participants had while they were awake powerfully and unambiguously resurfaced in the dreams they had at night. – pg. 204
Maybe dreams, like heat from a lightbulb, serve no function. Maybe they are of no use: simply an unintended by-product of REM sleep. Walker says this is not true. REM sleep in necessary, but REM sleep alone is not sufficient. Dreams are NOT the heat of the lightbulb. – pg. 206-207
Dream Functionality – REM sleep dreaming dissolves emotion from experience. You have not forgotten the memory, but you have cast off the emotional charge. Stress-related brain chemistry drops during the dreaming state. In fact, dreaming of a very specific kind is required during REM: it has to be about the emotional themes and sentiments of waking trauma. Another distinct benefit? Intelligent information processing that inspires creativity and promotes problem solving. – pg. 209-211, 219
Only patients who were expressly dreaming about their painful experiences gained clinical resolution from their despair, while those who dreamt (but not about the painful experience) could not get past the event. – pg. 211
“As he slept, he dreamed, and his dreaming brain accomplished what his waking brain was incapable of.” – pg. 220
“Little wonder, then, that you have never been told to ‘stay awake on a problem.’ Instead, you are instructed to ‘sleep on it.’ Interestingly, this phrase, or something close to it, exists in most languages.” – pg. 229
NREM sleep solidifies memories, while REM sleep and dreaming takes that which we have learned in one experience setting and applies it to others stored in our memories. – pg. 231
Thomas Edison used to sleep in a chair holding ball bearings. The minute his muscles relaxed (as he slipped into REM sleep), he would drop the ball bearings onto a metal saucepan below which would wake him up. Edison would then write down all of the creative ideas that were flooding his dreaming mind. – pg. 232
“We must drop core body temperature (by 2-3 degrees Fahrenheit) to initiate and maintain sleep.” – pg. 245, 275
“I suspect that you cannot recall any truly significant action in your life that wasn’t governed by two very simple rules: staying away from something that would feel bad, or trying to accomplish something that would feel good.” – pg. 247
“Emotions in appropriate amounts make life worth living. They offer a healthy and vital existence, psychologically and biologically speaking. Take them away, and you face a sterile existence with no highs or lows to speak of. Emotionless, you will simply exist, rather than live.” – pg. 247
REM-Sleep Rebound – When the brain (of an addict) begins feasting on REM sleep, binging in a desperate effort to recover that which it has been long starved of. – pg. 272
“Sleep may have more of an influence on exercise than exercise has on sleep. […] Try not to exercise right before bed. Body temperature can remain high for an hour or two after physical exertion. Should this occur too close to bedtime, it can be difficult to drop your core temperature sufficiently to initiate sleep due to the exercise-driven increase in metabolic rate.” – pg. 294-295
Studies showed that naps as short as 26 minutes still offered a 34% improvement in task performance, and more than 50% increase in overall alertness. – pg. 305
“The return on sleep investment in terms of productivity, creativity, work enthusiasm, energy, efficiency – not to mention happiness, leading people to work at your institution, and stay – is undeniable.” – pg. 332
“We need better public campaigns educating the population about sleep.” – pg. 337
“I believe it is time for us to reclaim our right to a full night of sleep, without embarrassment or the damaging stigma of laziness. […] Then we may remember what it feels like to be truly awake during the day, infused with the very deepest plentitude of being.” – pg. 340
TIPS [that I found relevant]: (1) Don’t take naps after 3pm, and (2) A relaxing activity, such as reading or listening to music, should be a part of your bedtime ritual. – pg. 342