Sleep, Dreaming and Circadian Rhythms

Question 1

What are the three standard physiological measures of sleep?

Answer 1

• Electroencephalogram (EEG), reveals brainwaves
• Electrooculogram (EOG) records eye movements during REM sleep
• Electromyogram (EMG) detects loss of activity in neck muscles

Question 2

What is characteristic of Stage 1 sleep?

Answer 2

• EEG similar to awake but slower

- low-voltage, high frequency

Question 3

What is characteristic of Stage 2 sleep?

Answer 3

• K complexes, one large negative wave followed by one large positive wave
• Sleep spindles, bursts of 12-14 Hz waves

Question 4

What is characteristic of Stage 3 and 4 sleep?

Answer 4

Large and slow Delta waves

Question 5

What is the progression of sleep stages over a typical night’s sleep?

Answer 5

• Cycle through stages 1-4
• 4 through 1 to REM
• Repeat 1-4 and 4-REM cycle
• Stages 3 and 4 occur less as night goes on

Question 6

What is the adaptation theory of sleep?

Answer 6

• Sleep is the result of an internal timing mechanism

- sleep evolved to protect us from the dangers of the night

Question 7

What is the recuperation theory of sleep?

Answer 7

• Sleep is needed to restore homeostasis

- Wakefulness causes a deviation from homeostasis

Question 8

What are the two consistent effects of REM sleep deprivation?

Answer 8

• Proceed more rapidly into REM as REM deprivation increases

- more time spent in REM when deprivation is over

Question 9

What is the function of slow-wave sleep?

Answer 9

• restorative

- short sleepers get as much SWS as long sleepers

Question 10

What are zeitgebers?

Answer 10

stimuli that reset circadian rhythms

Question 11

What are the effects of damage to the posterior hypothalamus ?

Answer 11

excessive sleep

Question 12

What are the effects of damage to the anterior hypothalamus?

Answer 12

inability to sleep

Question 13

What are the characteristics of iatrogenic insomnia?

Answer 13

• physician created

- consequence of sleeping pill use

Question 14

What are the characteristics of sleep apnea?

Answer 14

• stop breathing during the night, repeated awakenings

- obstructive (vigorous snorers) or central (failure of CNS to stimulate respiration)

Question 15

What are the characteristics of periodic limb movement disorder?

Answer 15

• unconscious twitching of the body, usually legs

- most sufferers unaware of why they don’t feel rested

Question 16

What are the characteristics of restless leg syndrome?

Answer 16

• movement of legs is consciously caused
• sufferers complain of a hard-to-describe tension/uneasiness in legs that movement relieves
• keeps them from falling asleep

Question 17

What are the characteristics of narcolepsy?

Answer 17

• severe daytime sleepiness and repeated brief daytime sleeping
• “sleep attacks”
• cataplexy, loss of muscle tone while awake
• sleep paralysis, paralyzed while falling asleep or upon waking
• hypnagogic hallucinations, dreaming while awake