PSY Module 8

"For what one has dwelt on by day, these things are seen in visions of the night" (Menander of Athens, Fragments). How might the information-processing perspective on dreaming interpret this ancient Greek quote?

The information-processing explanation of dreaming proposes that brain activity during REM sleep enables us to sift through what one has dwelt on by day.

During the NREM-1 sleep stage, a person is most likely to experience

hallucinations

sleep

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

A well-rested person would be more likely to have _________ (trouble concentrating/quick reaction times) and a sleep-deprived person would be more likely to ____________ (gain weight/fight off a cold).

quick reaction times, gain weight

REM Sleep

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.

insomnia

recurring problems in falling or staying asleep.

The ___________ nucleus helps monitor the brain's release of melatonin, which affects our ____________ rhythm.

suprachiasmatic, circadian

circadian rhythm

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

delta waves

the large, slow brain waves associated with deep sleep.

alpha waves

the relatively slow brain waves of a relaxed, awake state

REM rebound

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

What five theories propose explanations for why we dream?

(1) Freud's wish-fulfillment (dreams as a psychic safety valve), (2) information-processing (dreams sort the day's events and form memories), (3) physiological function (dreams pave neural pathways), (4) neural activation (REM sleep triggers random neural activity that the mind weaves into stories), and (5) cognitive development (dreams reflect the dreamer's developmental stage).

What are five proposed reasons for our need for sleep?

(1) Sleep has survival value. (2) Sleep helps restore and repair brain tissue. (3) During sleep we consolidate memories. (4) Sleep fuels creativity. (5) Sleep plays a role in the growth process.

Kelsie's roommate, Janice, fell asleep about 25 minutes ago. Now, Kelsie needs to awaken her so that they can get to a party on time. Janice is sleep talking about her boyfriend's dog. When Kelsie begins laughing, Janice wakes up. She was in NREM-_____ sleep.

2

Sleep spindles occur during NREM-_____ sleep.

2

As the night progresses, what happens to the REM stage of sleep?

It increases in duration.

Jasminder is creative and smart, whereas Gemma tends to take initiative and does better in school. Which woman is most likely the night owl?

Jasminder

Jasper stays up very late most Saturday nights. Getting up early on Monday morning is difficult for him because he often sleeps until noon on Sunday and has trouble going to sleep at a reasonable time on Sunday night. What advice would help him with his Monday morning problem?

Jasper should try to maintain the same bedtime on weekends as he does during the rest of the week.

How does bright light contribute to wakefulness?

Light striking the retina signals the suprachiasmatic nucleus to suppress the pineal gland's production of the sleep hormone melatonin.

The brain emits large, slow delta waves during _________ sleep.

NREM-3

How do biology and environment interact in our sleep patterns?

Our biology—our circadian rhythm as well as our age and our body's production of melatonin (influenced by the brain's suprachiasmatic nucleus)—interacts with cultural expectations and individual behaviors to determine our sleeping and waking patterns.

How do our biological rhythms influence our daily functioning?

Our bodies have an internal biological clock, roughly synchronized with the 24-hour cycle of night and day. This circadian rhythm appears in our daily patterns of body temperature, arousal, sleeping, and waking. Age and experiences can alter these patterns, resetting our biological clock.

If you gently awaken someone who is in _____ sleep, the person is likely to report being in the middle of an interesting dream.

REM

The tendency for REM sleep to increase following REM sleep deprivation is referred to as

REM rebound

How has neural activation been used to explain why we dream?

The activation-synthesis theory suggests that dreams are the brain's attempt to synthesize random neural activity.

How does sleep loss affect us, and what are the major sleep disorders?

Sleep deprivation causes fatigue and irritability, and it impairs concentration, productivity, and memory consolidation. It can also lead to depression, obesity, joint pain, a suppressed immune system, and slowed performance (with greater vulnerability to accidents). Sleep disorders include insomnia (recurring wakefulness); narcolepsy (sudden uncontrollable sleepiness or lapsing into REM sleep); sleep apnea (the stopping of breathing while asleep; associated with obesity, especially in men); night terrors (high arousal and the appearance of being terrified; NREM-3 disorder found mainly in children); sleepwalking (NREM-3 disorder also found mainly in children); and sleeptalking.

what is sleep?

Sleep is the periodic, natural loss of consciousness—as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation.

What are sleep's functions?

Sleep may have played a protective role in human evolution by keeping people safe during potentially dangerous periods. Sleep also helps restore and repair damaged neurons. REM and NREM-2 sleep help strengthen neural connections that build enduring memories. Sleep promotes creative problem solving the next day. Finally, during deep sleep, the pituitary gland secretes a growth hormone necessary for muscle development.

What functions have theorists proposed for dreams?

There are five major views of the function of dreams. (1) Freud's wish-fulfillment: Dreams provide a psychic "safety valve," with manifest content (story line) acting as a censored version of latent content (underlying meaning that gratifies our unconscious wishes). (2) Information-processing: Dreams help us sort out the day's events and consolidate them in memory. (3) Physiological function: Regular brain stimulation may help develop and preserve neural pathways in the brain. (4) Neural activation: The brain attempts to make sense of neural static by weaving it into a story line. (5) Cognitive development: Dreams reflect the dreamer's level of development. Most sleep theorists agree that REM sleep and its associated dreams serve an important function, as shown by the REM rebound that occurs following REM deprivation in humans and other species.

What do we dream?

We usually dream of ordinary events and everyday experiences, most involving some anxiety or misfortune. Fewer than 10 percent of dreams among men (and fewer still among women) have any sexual content. Most dreams occur during REM sleep.

Why would communal sleeping provide added protection for those whose safety depends upon vigilance, such as these soldiers?

With each soldier cycling through the sleep stages independently, it is very likely that at any given time at least one of them will be awake or easily wakened in the event of a threat.

What is the difference between narcolepsy and sleep apnea?

With narcolepsy, the person periodically falls directly into REM sleep, with no warning; with sleep apnea, the person repeatedly awakens during the night.

What is the biological rhythm of our sleeping and dreaming stages?

Younger adults cycle through four distinct sleep stages about every 90 minutes. (The sleep cycle repeats more frequently for older adults.) Leaving the alpha waves of the awake, relaxed stage, we descend into the irregular brain waves of non-REM stage 1 (NREM-1) sleep, often with hallucinations, such as the sensation of falling or floating. NREM-2 sleep (in which we spend the most time) follows, lasting about 20 minutes, with its characteristic sleep spindles. We then enter NREM-3 sleep, lasting about 30 minutes, with large, slow delta waves. About an hour after falling asleep, we begin periods of REM (rapid eye movement) sleep. Most dreaming occurs in this stage (also known as paradoxical sleep) of internal arousal but outward paralysis. During a normal night's sleep, NREM-3 sleep shortens and REM and NREM-2 sleep lengthens.

suprachiasmatic nucleus (SCN)

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

dream

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

night terrors

a sleep disorder characterized by high arousal and an appearance of being terrified; unlike nightmares, night terrors occur during NREM-3 sleep, within two or three hours of falling asleep, and are seldom remembered.

sleep apnea

a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakening

narcolepsy

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

manifest content

according to Freud, the remembered story line of a dream (as distinct from its latent, or hidden, content)

latent content

according to Freud, the underlying meaning of a dream (as distinct from its manifest content)

Which of the following is NOT one of the theorized purposes of dreams?

assisting personality development

hallucinations

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

One in 10 adults complains of nightly problems falling or staying asleep, a sleep disorder called _____.

insomnia

In interpreting dreams, Freud was most interested in their

latent content, or hidden meaning.