L9: Sleep

Question 1

What are the main differences between REM and NREM sleep?

Answer 1

REM: Body is paralysed, eyes move side to side quickly and heavy dream activity occurs. Happens in short bursts

NREM: Body is able to move, eyes remain still. Growth hormone is produced and cellular repair begins in NREM

Question 2

What are the frequency waves/voltage like in a) deep sleep b) Wakefulness/REM

Answer 2

Deep sleep: Low frequency, Higher voltage brain wages

Wakefulness/REM: High frequency, low voltage waves

Question 3

What happens in Stage 2 of NREM sleep?

Answer 3

K-complex and sleep spindles

Question 4

What are K-complex and Sleep spindles?

Answer 4

K-Complex: Sharp wave associated with temporary inhibition of neuronal firing

Sleep spindles: 12-14Hz waves during burst that lasts half a second

Question 5

What are the 2 theories of sleep?

Answer 5

1) Recuperation hypothesis- Argues sleep is essential for physiological functioning. Restores energy, clears toxins, maintains homeostasis
2) Predation hypothesis- We dont need sleep but it is adaptive. Less likely to have accidents or injury

Question 6

What happens if you sleep without envrionmental cues?

Answer 6

Circadian cycle lasts slightly longer, people in lab environments experience desyncronisation.

Question 7

What did Ralph et al 1990 do?

Answer 7

Put lesioned SCN into 20 hour cycles hamsters, and found their circadian cycle changed to 25 hours.

Question 8

What are ‘evening type’ individuals more likely to engage in?

Answer 8

Impulsive, risky behaviour. Also predicted poorer grades in school.

Question 9

What is melatonin and where is it regulated?

Answer 9

Promotes sleep. Regulated by the SCN

Question 10

What are the brain areas involved in sleep?

Answer 10

Anterior hypothalamus- promotes sleep
Posterior hypothalamus- promotes wakefulness
Reticular formation- slow wave sleep (SWS)

Question 11

What are causes of insomnia?

Answer 11

Increased tolerance to medication. Symptoms: sleep apnea, PLMD

Question 12

What are symptoms of hypersomnia?

Answer 12

Narcolepsy, Cataplexy, Sleep paralysis, Hyphagogic hallucinations, REM-Sleep behaviour disorder

Question 13

What are the physiological and psychological effects of sleep deprivation?

Answer 13

Physiological: reduced body temp, increase in blood pressure, decreased immune functioning, hormonal fluctuations

Psychological: Executive function-decreased performance, increased stress. Attention performance and psychomotor speed is reduced

Question 14

What are the 2 theories of why we need REM sleep?

Answer 14

1) Argues REM replenishes cognitive functioning such as memory consolidation/emotion
2) Evolutionary-adaptive hypothesis- REM is adaptive and prepares for wakefulness in an environment where immediate activity may be required

Question 15

What lab study demonstrated the importance of REM sleep?

Answer 15

2 mice, in a rotating dick above water. 1 rat was dunked in water when it went into REM sleep, other was not.

The experimental rat died after 12 days. However, Stress = large confound

Question 16

What did Friedmann and Mullaney do?

Answer 16

Reduced pp’s sleep by 30 mins every 2 weeks to 6.5 hours, then every 3 weeks to 5 hours. Then for a further 4 weeks until pp wants to stop.

2pp’s stopped at 5.5 hours. 4 pp’s stopped at 5hrs. 2 pp’s stopped at 4.5hrs.

Increased sleep efficency and SWS. Decreased time to fall asleep and number of nightly awakenings.

Question 17

What do we know about microsleep/napping?

Answer 17

It has restorative recuperating properties and helps avoid sleep deprivation

Question 18

What variables did Tamakoshi and Ohno control for?

Answer 18

Depression, Smoking, Alcohol, Education, Martial Status

Question 19

What are the 5 dimensions of sleep health?

Answer 19

Duration
Alertness
Timing
Efficiency
Sleep quality

DATES

Question 20

What are the 4 aspects of Buysse’s sleep health model?

Answer 20

Sleep dimension
Genetic, Epigenetic, Molecular and cellular processes
System-level processes
Health, disease and function