# Sleep
## November 16th, 2020
- So, let's watch a "sleep video" from "60 minutes" and then talk about the concept of the sleep chapter from the textbook
- Why do we sleep? There are different theories, but sleep is critical; lack of sleep will kill you about as quickly as a lack of food, and almost every animal seems to sleep (even fruit flies, whose mating patterns become significantly impaired with lack of sleep)
- Students who've gone 24 hours without sleep do 40% worse on memory tests, but getting good amounts of sleep help improve memory significantly
- At the UPenn Sleep Lab, they've found that getting only 4 hours of sleep per night significantly affects your memory, speed of reasoning, etc.; just 1 night without sleep is enough for things
- Similarly, Virginia Tech found that drowsiness was the number 1 cause of car accidents, and likely was a factor in many famous accidents like 3 Mile Island
- Sleep deprivation tends to lead not to complicated mistakes, but simple ones
- ...and people who are sleep deprived often think they've adapted to the lack of sleep, but the UPenn study showed that these same impairments still exist in sleep-deprived people who claim they've adjusted
- Similarly, a lack of sleep can lead to massive mood swings, since a lack of sleep leads to a hyperactive brain response - the same pattern as in some mental disorders
- Lack of sleep also leads to higher risks of diabetes, since sleep-deprived people crave more and sugary foods AND don't metabolize food as effectively
- So, some review questions from the video:
- How much of our lives do we spend sleeping?
- ~1/3rd
- How much sleep does an average American get?
- 6.7 hours
- How does this compare to the 1960s?
- It's decreased by 16% (the 60s averaged about 8 hours)
- How does sleep deprivation affect learning, memory, and reaction time?
- It slows down all 3! But it has a cumulative effect: longer times without sleep make things worse (24 hours without sleep led to a 40% worse performance on memory tests)
- How little sleep deprivation can cause changes?
- 1 night of 4-5 hours of sleep begins to affect memory and thinking speed
- What does current research suggest about human adaptation to chronic sleep deprivation?
- They CAN'T adapt to it, even if they think they can
- How does sleep deprivation affect hunger and blood sugar levels?
- It increases them!
- Short sleep times help lead to what chronic disease?
- Diabetes, since a lack of sleep slows down the body's production of leptin (makes you feel full). It also increases risk from obesity, heart disease, high blood pressure, and stroke
- How do sleep cycles change with age?
- As you get older, you spend less time in deep sleep
- Do naps help with lack of sleep?
- They help, but can't fully make up for a lack of 7.5-8 hours of total sleep
- According to the ACHA, what percent of college students report getting enough sleep to feel well rested 6/7 days of the week?
- Only 11.8%!
- What percent of students felt sleepy at least 3 days a week?
- Over 68%!
- Lack of sleep affects what dimensions of health?
- EVERY dimension, although environmental and spiritual are probably less affected
- At what age are men at the highest risk for drowsy driving accidents?
- 17-23 - that's YOU, people!
- These accidents are typically single-car accidents that involve going off the road late at night
- Where does lack of sleep fall on the causes of academic performance?
- It's the 3rd most prevalent cause of academic failure (after stress and anxiety)
- What are the 2 biological purposes of sleep?
- Conserving body energy/resting the body
- This means your body temperature drops, you burn fewer calories, your metabolism slows, etc.
- Restores energy/healing
- A few ways sleep maintains your physical health:
- It keeps your immune system spiffy and your white blood cell count high
- Reduces the risk for cardiovascular disease (by lowering blood pressure)
- Contributes to a healthy metabolism and controlled body weight
- Keeps neurologic function regular
- A lack of sleep can lead to difficulty concentrating, poor memory, reduced thinking speed, and a tendency to get "stuck in a rut"
- Studies consistently show pulling an "all-nighter" is a bad idea if you want to be maximally productive
- Sleep improves your motor function; a lack of sleep impairs it, similarly to driving drunk
- Stress and sleep have a HUGE link, but a complex one
- Stress can lead to a lack of sleep, as can other mental health issues
- Similarly, a lack of sleep leads to higher stress levels and an increased risk (~2x) of developing depression
- What actually happens when you sleep, though?
- REM sleep is energizing, but non-REM (NREM) sleep is restorative and when the body heals itself
- This is because the body temperature and energy use decline, sensation is dulled, heart rate and breathing decreases, and digestive processes speed UP in NREM sleep (which has 4 distinct stages)
- REM (rapid-eye movement) is when dreaming takes place; most of your muscles are paralyzed except for your eyes and muscles
- Your sleep patterns follow the circadian rhythm, which is regulated by your PINEAL GLAND via a hormone called MELATONIN
- Your sleep stages are mostly 90-minute long NREM sleep stages, interspersed with short periods of REM
- NREM phases become slightly shorter as the night goes on
- To sleep better, cut technology out of your bedtime routine, don't drink caffeine (as this blocks adenosine), don't nap in the late afternoon, don't engage in strenuous exercise or heavy eating or mentally strenuous activities, etc.
- Make sure to avoid using phones especially; blue light devices can significantly reduce melatonin production (which is the hormone that makes you fall asleep)
- *quickfire slides to review at your leisure*