Sleep

Question 1

What is a circadian rhythm?

Answer 1

Our internal 24 hour cycles

Question 2

What are ultradian rhythms?

Answer 2

Rhythms shorter than a 24 hour cycle

Question 3

What are the features of circadian rhythms?

Answer 3

> Adaptation
Built into the CNS
Internally regulated
Can be regulated by external cues

Question 4

What did Kleitman (1939) demonstrate?

Answer 4

That without any external cues people operate naturally on a circadian (24.5 hour) cycle

Question 5

What biological factors influence circadian rhythms?

Answer 5

> Neural activity
Hormone production
Cell regeneration

Question 6

How does hormone production influence circadian rhythms?

Answer 6

Most hormone are secreted at different rates at different times

Question 7

How does cortisol secretion influence circadian rhythms?

Answer 7

Cortisol levels increase sharply in the early morning and gradually reduce throughout the day

Question 8

What controls the sleep/wake cycles?

Answer 8

The suprachiasmatic nucleus

Question 9

Where is the suprachiasmatic nucleus located?

Answer 9

In the hypothalamus

Question 10

How does the suprachiasmatic nucleus (SCN) influence the sleep/wake cycle?

Answer 10

> Visual system registers sunlight decreases
SCN increases production of melatonin
Melatonin reduces activity and makes you feel sleepy

Question 11

What effect does GABA have on the suprachiasmatic nucleus?

Answer 11

> Excites dorsal

> Inhibits ventral

Question 12

What are the parameters of brainwaves?

Answer 12

> Frequency (Hz)

> Amplitudes (um)

Question 13

What are the types of brain wave?

Answer 13

> Alpha
Beta
Theta
Delta

Question 14

What are the features of waking brain waves?

Answer 14

> Low amplitude

> High frequency

Question 15

What are the features of brain waves during Stage 1 sleep?

Answer 15

Mostly theta waves

Question 16

What are the features of brain waves during Stage 2 sleep?

Answer 16

> Sleep spindles

> Brief periods of high amp, high freq

Question 17

What are the features of brain waves during Stage 3 sleep?

Answer 17

Delta waves

Question 18

What are the features of brain waves during Stage 4 sleep?

Answer 18

Mostly delta waves

Question 19

What are the features of brain waves during REM sleep?

Answer 19

> Rapid eye movement

> Otherwise identical to Stage 1

Question 20

What are the features of REM sleep?

Answer 20

> Decreased awareness threshold
Autonomic arousal
Vestibular activation
Genital arousal

Question 21

What is vestibular activation?

Answer 21

> Spatial orientation
Balance
Movement

Question 22

What are the psychological factors associated with sleep?

Answer 22

> Facilitation through sleep

> Impairment through deprivation

Question 23

What cognitive processes occur during sleep?

Answer 23

> Learning

> Problem solving

Question 24

What are the cognitive processes thought to be impaired by sleep disruption?

Answer 24

> Attention and memory

> Decision making

Question 25

Does sleep enhance learning?

Answer 25

Yes

Question 26

What evidence is there that sleep enhances learning?

Answer 26

> Motor learning > Memory recall > Perceptual motor tasks

Question 27

What have associative learning tasks demonstrated about sleep?

Answer 27

Learning shows offline consolidation of knowledge acquired (Walker and Stickgold, 2004)

Question 28

What did Walker and Stickgold (2004) demonstrate?

Answer 28

That after sleep previously acquired knowledge is consolidated

Question 29

Who demonstrated that sleep consolidates knowledge?

Answer 29

Walker and Stickgold (2004)

Question 30

Theoretically, why does sleep have consolidation benefits?

Answer 30

Sleep includes the neural reorganisation of memory, improving efficiency of storage and easing recall

Question 31

What neurological evidence is there that sleep deprivation has an effect on the formation memory?

Answer 31

Sleep deprivation is linked to impaired hippocampal function

Question 32

What did Wagner et al (2004) demonstrate?

Answer 32

That sleep is either reprocessing or reorganising

Question 33

What did Dickinson and Drummond (2008) demonstrate?

Answer 33

Bayesian updating is resilient to sleep deprivation

Question 34

What did Dickinson and Drummond (2008) find?

Answer 34

> Bayesian reasoning task > Sleep deprived / rested > No differences in performance > Differences in strategy

Question 35

What impact does shift work have?

Answer 35

> Physical measures (stress) > Neurobiological > Cognitive measure of behaviour (arousal and attention)

Question 36

What did Rouch et al ( 2005) find?

Answer 36

Long term shift work was detrimental to memory, attention and decision making

Question 37

What did Washburn (1992) find?

Answer 37

> Nurses > Fatigue increases during nightshift > Performance and alertness increase during nightshift

Question 38

Who demonstrated that performance and alertness in nurses was increased at the end of the night shift?

Answer 38

Washburn (1992)

Question 39

What did Peacock et al (1989) find?

Answer 39

> Policemen > Fatigue increases during nightshift > Performance and alertness increase during nightshift

Question 40

Who demonstrated that performance and alertness in policemen was increased at the end of the night shift?

Answer 40

Peacock et al (1989)

Question 41

What did Muecke (2005) propose?

Answer 41

That at the end of a shift ppl may start using compensatory strategies to boost performance

Question 42

What did Rickard et al (2008) demonstrate?

Answer 42

Evidence of offline learning may be artefacts of: > Averaging methods >Time-of-day testing

Question 43

What are the methodological limitations of shift pattern studies?

Answer 43

> Before-after designs > Shift length > Cross comparisons

Question 44

What are the limitations of before-after designs wrt shift pattern studies?

Answer 44

Usually conducted once, when one group is going off shift and one group is going on. Doesn't look at same group performance

Question 45

What are the shift length limitations of shift pattern studies?

Answer 45

Most studies don't control for shift length, combinations, speed of rotation or direction of rotation

Question 46

What are the cross comparison limitations of shift pattern studies?

Answer 46

> Failure to detail differences in task requirement on-job | > Don't control for levels of physical activity on shift