Chapter 5

Question 1

___% of adults sleep less than 7 hrs/day, ____% sleep less than the recommended 8 hours

Answer 1

35% sleep less than 7, 66% sleep less than 8 hrs

Question 2

routinely sleep less than 6-7 hours a night…

Answer 2

From large epidemiological studies:
-doubles risk for cancer
-increases risk for Alzheimer’s Disease
-disrupts blood sugar levels
-increases risk for cardiovascular disease, stroke, and heart failure

Question 3

When we lose an hour of sleep in the spring (the “natural experiment” on effects of losing sleep) what do we see as the effects?

Answer 3

increase in…
-fatal traffic accidents
-ER visits, heart attacks
-workplace injuries

Question 4

sleep deprivation effects comparable to effect of blood alcohol level of about ___% (can be as harmful as)

Answer 4

.05 —-> this causes lowered alertness, slower reaction time, reduced ability to track moving objects (**visual attention, motor behaviors)

Question 5

Circadian rhythm

Answer 5

naturally occuring 24 hour cycle
-circa (“around) dian (“day”)
-internal “natural” clock is a little longer than 24 hours (24 hrs 11 mins)
-internal clock is then calibrated by experiences and environmental cues (light-dark cycles, clocks, etc)

Question 6

Suprachiasmatic Nucleus (SCN)

Answer 6

like the body’s master clock
-tiny cluster of around 20,000 neurons located in hypothalamus (above where the optic nerves cross called the optic chiasm)
-job is to keep track of time and control circadian rhythms
-gets direct input from the eye (light signals) so it can adjust your internal clock
-regulates release of melatonin by the pineal gland

Question 7

What do ablation studies show about removing SCN in rodents?

Answer 7

shows that the amount of sleep was not disrupted, however the timing of sleep was (the sleep-wake cycle)

Question 8

how does the SCN regulate the release of melatonin?

Answer 8

by the Pineal gland

during nighttime: SCN communicates signal to Pineal gland to release melatonin

during daytime: SCN communicates signal to Pineal gland to stop the release of melatonin

Question 9

Explain Process S / “Homeostatic Sleep Drive”

Answer 9

Acts as a pressure gauge– the longer you stay awake, the more “sleep pressure” builds and your body produces chemicals (like adenosine) that make you feel increasingly tired

Question 10

Adenosine

Answer 10

Chemical that builds up in your brain the longer you go without sleep

Creates sleep drive and slows down neuronal activity**

Question 11

How do caffeine and adenosine relate?

Answer 11

Caffeine acts as an adenosine receptor antagonist, TEMPORARILY blocking the effects of adenosine

Question 12

What happens when Process- C (circadian rhythm) and Process-S (sleep drive) are aligned?

Answer 12

produces regular sleep-wake cycle! two processes are aligned but still independent

urge to be awake is strong (melatonin is low and adenosine is low) urge to be asleep is strong (melatonin is high, adenosine is high)

Question 13

The Randy Gardner Experiment

Answer 13

17 yr old stayed up for 264 hours and 12 mins

findings:
day 2: difficulty concentrating
3: mood changes, nausea
4: memory lapses, hallucinations
7: slurred speech
9: blurred vision, wouldn’t speak in complete sentences

Question 14

Studying the sleeping brain: Electroencephalography (EEG)
What do the different waves show

Answer 14

Typical EEG cap used during sleep research with electrodes next to eye

Beta waves: alert, active, awake, engaged
Alpha waves: rest, relaxed, drowsy
Theta waves: shallow sleep
Delta waves: deep sleep

Question 15

Studying the sleeping brain: Electroencephalography (EEG)
How does this reveal the different stages of sleep (what do specific waves represent)?

Answer 15

NREM: Non-Rapid Eye Movement Sleep
Stage 1: Theta waves
Stage 2: Theta waves, sleep spindles, K Complex
Stage 3:/4: Delta waves (slow wave sleep)

REM: Rapid Eye Movement Sleep
Similar to awake/beta brainwaves– Paradoxical sleep**(your body looks deeply asleep but your brain activity during REM is very similar to being awake)

in REM, eyes move in quick bursts, typical burst last ~7 seconds on average, these often line up with dream activity (like your watching something moving)

Question 16

How long is one cycle NREM –> REM? how many cycles every night?

Answer 16

90 mins on average, one night you typically go through 4-6 of these cycles

Question 17

levels of REM when getting 1-4 hours vs 4-8 hours

Answer 17

1-4: less REM, more deep sleep, delta waves, slow-wave sleep

4-8: more REM, spend a lot of time in NREM stage 2 (lighter sleep marked by sleep spindles)

Question 18

what are sleep spindles

Answer 18

little bursts of brainwave activity that help with memory and learning

during NREM stage 2 (can show up in other stages but most frequent/prominent here)

Question 19

manifest vs latent

Answer 19

So in your example: you dream you win the lottery (manifest), but it might really be about wanting freedom or feeling lucky (latent).

According to Sigmund Freud, the two types of dream content are:

Manifest content – the actual storyline or images you remember from the dream.

Latent content – the hidden, symbolic meaning behind the dream, reflecting unconscious desires or thoughts.

Question 20

somnambulism

Answer 20

sleep walking

Question 21

pattern of sleep from stage 1 to REM, as measured by EEG patterns

Answer 21

theta waves; sleep spindles and K complexes; delta waves; fast, random waves

Question 22

dream consciousness is characterized by

Answer 22

intense emotion
uncritical acceptance
illogical thought
difficult to remember