Sleep Disorders and Unusual Sleep Phenomena
In this lesson, we'll cover a variety of sleep disorders and unusual sleep phenomena, which range from mild (and maybe even enjoyable in the case of lucid dreaming) to deadly.
1) First, watch these videos:
2) Next, answer these questions to test your understanding:
1. Sleep paralysis is a state of immobility that occurs just before falling asleep or upon awakening. It is thought to result from an overlap between wakefulness and which sleep stage?
- A. non-REM stage 1
- B. non-REM stage 2
- C. non-REM stage 3
- D. REM sleep
Show Answer
Correct answer: D
Sleep paralysis is generally believed to occur due to an overlap between REM sleep and wakefulness. During REM sleep, neurons in the brainstem inhibit spinal cord neurons, causing a widespread loss of muscle movement. Sleep paralysis appears to result from this REM-related paralysis persisting into wakefulness.
2. Type 1 narcolepsy is a sleep disorder characterized by excessive daytime sleepiness and sudden muscle weakness (cataplexy). It is most directly associated with a deficiency of which of the following neurochemicals?
- A. dopamine
- B. serotonin
- C. acetylcholine
- D. orexin (hypocretin)
Show Answer
Correct answer: D
Narcolepsy is a chronic condition that causes excessive daytime sleepiness and leads to an increased tendency to fall asleep during daytime activities. Narcolepsy type 1 is linked to a loss of orexin-producing neurons in the hypothalamus, leading to low orexin levels. Orexin neurons have an excitatory effect on several regions of the brain that are involved in promoting wakefulness and suppressing REM sleep.
3. True or False: Lucid dreaming is a scientifically verified phenomenon that can occur during sleep.
- A. True
- B. False
Show Answer
Correct answer: A
Researchers have confirmed the occurrence of lucid dreaming through various methods. One approach involves instructing individuals to make specific eye movements upon entering a lucid dreaming state. Using this method, scientists have observed lucid dreamers making the specific eye movements as instructed, even though their brain activity indicated they were asleep.
4. Sleepwalking most commonly occurs during which stage of sleep?
- A. stage 1 (non-REM)
- B. stage 2 (non-REM)
- C. stage 3 (non-REM)
- D. REM sleep
Show Answer
Correct answer: C
Sleepwalking typically occurs during stage 3 non-rem sleep (also known as slow-wave sleep or deep sleep). It can also occur in stage 2, but this is much less common.
5. Fatal insomnia is a prion disease marked by progressively worsening sleep disturbances. It involves neurodegeneration that is most pronounced in which of the brain regions below?
- A. hippocampus
- B. cerebellum
- C. thalamus
- D. amygdala
Show Answer
Correct answer: C
In fatal insomnia, damage to the sleep-promoting regions of the thalamus is thought to be especially important to causing the insomnia that occurs in the disease.
