Module 8: Sleep and Dreams

Question 1

Sleep

Answer 1

A periodic, natural loss of consciousness as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation.

Question 2

Circadian Rhythm

Answer 2

Our biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle.

Morning nears —> body temperature rises, peaks during day, dips for a time in early afternoon, and begins to drop in the evening.

Question 3

When do we cycle between sleep stages?

Answer 3

Every 90 minutes

Question 4

REM (R) Sleep

Answer 4

Rapid eye movement sleep; a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active.

Question 5

Alpha Waves

Answer 5

The relatively slow brain waves of a relaxed, awake state.

What is seen on EEG when you are in bed with your eyes closed.

Question 6

NREM - 1 Sleep (N1)

Answer 6

• Slipping into sleep is an unremembered moment

- Is marked by slowed breathing and irregular brain waves

Question 7

Hallucinations

Answer 7

False sensory experiences, such as seeing something in the absence of an external visual stimulus.

• Can experience these during brief N1 sleep
• Sensation of falling —> hypnic jerk

Question 8

NREM - 2 Sleep (N2)

Answer 8

• Relax more deeply —> begin 20 minutes of NREM - 2
• Periodic sleep spindles —> bursts of rapid, rhythmic brain-wave activity that aid memory processing
• Could be awakened easily

Question 9

NREM - 3 Sleep (N3)

Answer 9

• Deep sleep
• Slow wave sleep lasts for 30 minutes
• Hard to awaken

Question 10

Delta Waves

Answer 10

The large, slow brain waves associated with deep sleep.

Question 11

When do you enter REM sleep and what happens to you?

Answer 11

• An hour after falling asleep
• For 10 minutes, your brain waves become rapid and saw toothed —> like those of nearly awake N1 sleep
• Unlike in N1, heart rate rises, breathing becomes rapid and irregular, and every half-minute eyes dart around in momentary bursts of activity behind closed lids.
• Eye movements announce beginning of a dream

Question 12

What happens to the brain and body in REM sleep?

Answer 12

• Brain’s motor cortex is active, but the brainstem blocks its messages —> leaves muscles relaxed
• Except for occasional twitch, you are essentially paralyzed
• Cannot be easily awakened
• Body is internally aroused, with waking-like brain activity, yet asleep and externally calm.

Question 13

Suprachiasmatic nucleus (SCN)

Answer 13

A pair of cell clusters in the hypothalamus that controls circadian rhythm. In response to light, the SCN causes the pineal glad to adjust melatonin production, thus modifying our feelings of sleepiness.

Question 14

Social Jetlag

Answer 14

• Staying up late on the weekends and sleeping in

- Then, going to sleep early on Sunday to get ready for the week

Question 15

Why do we sleep?

Answer 15

• Protects us
• Helps us recuperate —> restore the immune system and repair brain tissue
• Helps restore and rebuild our fading memories of the day’s experiences —> strengthens our memories by replaying recent learning
• Feeds creative thinking
• Supports growth

Question 16

Insomnia

Answer 16

Recurring problems in falling or staying asleep

Question 17

Narcolepsy

Answer 17

A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times.

Question 18

Sleep Apnea

Answer 18

A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings.

Question 19

Night Terrors

Answer 19

A sleep disorder characterized by high arousal and an appearance of being terrified; unlike nightmares, night terrors occur during N3 sleep, within two or three hours of falling asleep, and are seldom remembered.

Question 20

Dream

Answer 20

A sequence of images, emotions, and thoughts passing through a sleeping person’s mind.

Question 21

Freud’s Wish Fulfillment (Dream Theories)

Answer 21

Dreams provide a “psychic safety valve” - expressing otherwise unacceptable feelings; dreams contain manifest (remembered) content and a deep layer of latent content (a hidden meaning).

Question 22

Manifest Content

Answer 22

According to Freud, the symbolic, remembered story line of a dream.

Question 23

Latent Content

Answer 23

According to Freud, the underlying meaning of a dream.

Question 24

REM Rebound

Answer 24

The tendency for REM sleep to increase following REM sleep deprivation.

Question 25

Why do we dream? (Dream Theories)

Information - processing

Answer 25

Dreams help us sort out the day’s events and consolidate our memories.

Question 26

Why do we dream? (Dream Theories)

Physiological function

Answer 26

Regular brain stimulation from REM sleep may help develop and preserve neural pathways.

Question 27

Why do we dream? (Dream Theories)

Activation - synthesis

Answer 27

REM sleep triggers neural activity that evokes random visual memories, which our sleeping brain weaves into stories.

Question 28

Why do we dream? (Dream Theories)

Cognitive development

Answer 28

Dream content reflect dreamers’ level of cognitive development - their knowledge and understanding. Dreams simulate our lives, including worst-case scenarios.