Dement Ch. 10, 11, 12, 14 Flashcards
Describe extreme cases of sleep deprivation including Randy Gardner and Peter Tripp. What were the results, implications and after effects?
Randy Garner sought to break the world record for days awake. Dement helped him, and he made it. His recovery sleep told them that sleep debt is not a one to one ratio.
Peter Tripp used stimulants to keep himself awake for a charity event, and suffered hallucinations, for a time, a sleep theory revolved around this, but after Gardner, this theory was disproven.
What are microsleeps?
sleep periods lasting less than five minutes.
Describe the role of understanding animal sleep in understanding human sleep.
Though they are not directly comparable, understanding animals along the evolutionary chain can give us insights into the steps taken to evolve to where we are.
Describe the sleep of different animals discussed in the books.
Cats: They do not have consolidated sleep, and may have evolved this way to allow them to hunt in both the day and the night.
Dolphins:Evolved on land before moving to sea. Sleeps one hemisphere at a time, in two hour intervals, first left, than right until sleep requirements are met.
Birds:evolved independently of mammals, short bursts of REM like sleep, but no paralysis involved.
Reptiles:No REM, but do have a quiet period where they don’t react as well to outside stimuli.
Fish: rest on a leaf during downtime and have delayed reaction time during.
Mice:
Monkeys:
Platypus: one of most ancient mammals, forebrain is inactive during REM, much like human infants.
Describe the energy conservation theory of sleep. What animal research supports this?
Sleep provides a period where the body can restore energy, when periods of food sources tend to be scarce. Each animal species has evolved to sleep when both food and reproductive opportunities are low, thus energy conservation would make sense. Some animals have a metabolism so high that they cannot go hours without food or die, so sleeping when food is scarce prolongs their life.
Describe the survival mechanism/evolution theory of sleep.
That animals evolved to sleep during periods of increased vulnerability. For example, humans sleep during the night to avoid predators that would kill them.
Describe specific evidence that supports the Growth and Development theory of sleep (253-258).
THe fact that infants mirror the platypus may show an evolutionary chain. After 4 months of gestation, the human fetus has 200 billion nerve cells in the brain, 2X as many as it needs. Excess is eliminated in year 1. Infants w cataracts risk loss of development if they aren’t fixed promptly. Fetal brain uses artificial stimulation to help its visual centers develop (given that the womb is dark.) Upon birth, their eyes work fine, and that wouldn’t happen without prior stimulation.Reffwarg covered a kitten’s eye and its nerve cells started to atrophy. This means REM is important after birth.
What is the Roffwarg-Dement theory of sleep. Describe two problems with this theory. (256)
That REM sleep in the womb prepares the brain by giving it stimulation for the delicate nerve endings that would otherwise atrophy. This also allows the brain to be prepared to enter the world. It is difficult to test and if it is only for development, why would we have REM continue into adulthood?
Describe REM Sleep deprivation and it’s effects.
Depriving someone of only REM sleep. increased inflammatory response, weight issues, depression and memory problems, as well as death (at least in rats.)
Describe Roth & Roehrs yoked control sleep deprivation study (p 257). Methods, results, implications.
When they deprived an individual in the experimental group of REM, the other individual in the control group was also woken, though they were not in the same sleep stage. The results showed that the control group was more sleepy during the day than the experimental group because they had been deprived of NREM.
Modafinil
A drug used in the treatment of Narcolepsy that does not cause increased sleep debt.
Describe the results of the American Cancer Society’s study. (in regards to sleep.)
Stated habitual sleep time had the best correlation with mortality. Wasn’t linear. highest mortality rates were for under 4 hours or over nine. Lowest was around eight hours of sleep.
How much more likely are poor sleepers (versus good sleepers) likely to have health problems?
males: 6.5 times more likely
females: 3.5 times more likely
Describe the “cause and effect” relationship of sleep and length of one’s life
though eight hour sleepers live longer, the study did not prove a cause and effect relationship between sleep and longevity, though the results were very compelling. The answer may instead be discovered by the link between sleep and the immune system.
Does sleep deprivation cause a person to get sick? Explain.
No, it cannot cause illness, but it can make one susceptible to getting sick.
Generally, describe how the immune system works, including the role of interleukins.
Skin cells trap bacteria and shed off. blinking washes eyes with tear water, sweeping organisms into tear ducts to be destroyed. mucus in the nose traps airborne particles and if a cold is present, mucus washes out the virus. Acid in the stomach and immune cells in the intestine fight dangerous microbes.
Special cells in our body recognize whether other particles that are foreign and even kill off caner cells. Interleukins are messengers that mobilize the body to fight off an infection. immunoglobulins confront foreign bodies, and if dangerous, the body sends in T-cells, macrophages, and natural killer cells. They release enzymes that dissolve the cell membrane of the virus or cancer cell.
What role do interleukins play in sleep when we are sick?
it increases sleep pressure, and may turn off the body clock, allowing us to be awake a few hours, then sleep a few hours.