Sleep and dreams

Question 1

How do we define sleep

Answer 1

Sleep is a reversible state of reduced awareness of and responsiveness to the environment.

Question 2

NREM

Answer 2

Non-rapid eye movement

Question 3

Rem

Answer 3

Rapid eye movement

Question 4

what biological rhythm is Circadian?

Answer 4

around a day, 24 hours internally.

• e.g. the sleep-wake cycle.

Question 5

what biological rhythm is Ultradian?

Answer 5

less than a day, cycles that occur within a day

• e.g. temperature fluctuations, cognitive vigilance, sleep stages and hormonal.

Question 6

what biological rhythm is Infradian?

Answer 6

more than a day

• e.g. menstrual cycle 28 days.

Question 7

SCN

Answer 7

Suprachiasmatic Nucleus

Question 8

How does the SCN work ?

Answer 8

By using information obtained by the retina but the retinohypothalamic path, and by the clock and bmal1 cells creating cry and per which. This process takes 24hours and will block it while cry and per are active

Question 9

(Stanewsky, 2003)

Answer 9

• PER gene for the biological clock, was involved in all three mutations of fly suggesting that flys may have a sense of time

Question 10

(King & Takahashi, 2000)

Answer 10

• Mammals also carry the same gene, but it is referred to as the clock gene

Question 11

what happens if we Transect optic nerve before optic chiasm?

Answer 11

no light/dark entrainment

Question 12

Transect optic nerve after optic chiasm?

Answer 12

preserved light/dark entrainment

Question 13

what does the SCN control

Answer 13

Alert or awareness is controlled by the SCN

Question 14

what influences the SCN

Answer 14

influenced by light and other ‘zeitgebers’ – ‘time givers’, including social cues, noise, temperature

Question 15

No zeitgebers

Answer 15

However, without zeitgebers, organisms can adapt (e.g. blind mole rats) – the internal state used

Question 16

How does light effect the Scn

Answer 16

Light suppresses SCN firing and this, in turn, suppresses pineal production of melatonin

Question 17

how much sleep do people need ?

Answer 17

Newborn	up to 18 hours
1–12 months	14–18 hours
1–3 years	12–15 hours
3–5 years	11–13 hours
5–12 years	9–11 hours
Adolescents	9–10 hours
Adults, including elderly	7–8 (+) hours
Pregnant women	8 (+) hours

Question 18

How can we measure sleep ?

Answer 18

EEG
EOG
EMG
Actigraphy

Question 19

EEG

Answer 19

Electroencephalogram (EEG)

• Measures electrical activity of the brain

Question 20

EOG

Answer 20

Electrooculogram (EOG)

• Measures eye movements

Question 21

EMG

Answer 21

Electromyogram (EMG)

• Measures electrical activity of the muscles

Question 22

Actigraphy

Answer 22

Actigraphy

• sensor measures gross motor activity – crude measure such as fitbit

Question 23

Stage 1

Answer 23

refers to the transition of the brain from alpha waves to theta waves (theta activity)

Question 24

Stage 2

Answer 24

no eye movement or theta activity. There are sleep spindles, 1-2 second bursts of 12-14 Hz activity, and K complexes

Question 25

Stage 3

Answer 25

very slow brain waves (delta waves) that have a frequency of 1-4Hz

Question 26

Stage 4

Answer 26

delta waves predominate for a deeper level of sleep

Question 27

REM (‘paradoxical’) sleep

Answer 27

similar to wakefulness in terms of brain waves, blood pressure, temperature. Where dreams occur. Between 3-5 each night.