Investigate 5.1
Students’ own responses.
Review 5.1
Level of awareness
Content limitations
Controlled and automatic processes
Perceptual and cognitive distortions
Varied
Control over content
Ability to perform both
Less to no awareness
Fewer content limitations
Unable to perform either
Emotional awareness
No distortions Disorganised thoughts
(dreams) attention to stimuli lowered
Aware of emotions Intense or flat toned emotions
Self-control Less self-control
Aware of passing of time Distorted time orientation
Self-control
Time orientation
Investigate 5.2
Students’ own responses.
Investigate 5.3
1 40%
2 From late childhood to old age the amount of time spent in NREM slightly
3 increases and the amount of time spent in REM slightly increases. a.
14 hours b.
12–13 hours c.
10 hours d.
9 hours e.
8 hours
Investigate 5.4
Students’ own responses.
Investigate 5.5
1 The aim of this experiment was to investigate what signals can wake people who are deeply asleep.
2 It was hypothesised that a higher pitch and more complex tones are more likely to wake a person in stage 4 NREM sleep than a lower pitch and less complex tones.
3 The four different signals.
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4 The length of time it took for beta brainwave patterns to appear (participants waking).
5 Repeated measures.
6 The length of time it took for beta brainwave patterns to appear.
7 Counterbalancing is where half the participants are exposed to the control condition first and half are exposed to the control condition second. Then the opposite half is exposed to the experimental condition first, and control condition second. Counterbalancing is a type of experimental design in which all possible orders of presenting the variables are included. It is used when there are likely to be order effects.
8 Levels of awareness decrease during sleep.
9 We experience NREM stage 4 about an hour to two hours after we first fall asleep.
10 It is difficult to wake someone in stage 4 NREM sleep.
11 The typical brainwave patterns for stage 4 NREM sleep are delta, slow wave sleep.
12 Normal waking consciousness (NWC).
13 Participants are used to sleeping in their own homes and therefore an unfamiliar setting would not be present to confound the results.
14 A low pitch and a complex tone is significantly more likely to wake someone in stage 4 sleep.
15 Standard smoke alarms are currently high pitched with non-complex tones (pure) and are at least seven times less likely to wake an adult in deep sleep.
Review 5.2
1 NREM has non-rapid eye movement (little to no rolling of the eyes) and REM has rapid eye movement and more likely to experience dreaming. Different brain patterns are also evident.
2 Sleep is an example of a circadian rhythm.
3 NREM/REM cycle is an example of an ultradian rhythm.
4 a.
beta brainwave patterns b.
alpha brainwave patterns c.
alpha-theta brainwave patterns d.
theta brainwave patterns e.
theta-delta brainwave patterns f.
delta brainwave patterns g.
beta like, saw-tooth brainwaves
5 a.
Stage 1 b.
Stage 1 c.
Stage 2 d.
REM e.
Stage 4 f.
Stage 4 g.
Stage 4
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h.
REM i.
Stages 3 and 4 NREM
Review 5.3
1
Adaptive and evolutionary theories
Recovery and restorative theories
This theory proposes that we sleep in order to protect ourselves from danger. It suggests that we sleep at night, when it is dark, because that is the time that any predators would be out hunting.
Therefore, our likelihood of being attacked is reduced. This derives from our cavemen days.
This theory proposes that we sleep in order to rest and restore our body’s resources from the depletion that occurs during the day. When we sleep our cells, muscles, glands and organs have a chance to replenish. Sleep also replenishes the mental functions of our brain.
Limitations of this theory are that we may actually be at increased risk of being attacked when we sleep because we have reduced responses to stimuli and our reactions are lowered. It also fails to explain why we experience physiological and psychological problems when we are sleep deprived.
Limitations of this theory are that, even if we are well rested, we do not require less sleep. If you spend a day on the couch, you will require as much sleep as you would had you had a busy day.
2 a.
Adaptive and Evolutionary b.
Recovery and Restoration c.
Adaptive and Evolutionary d.
Adaptive and Evolutionary e.
Recovery and Restoration f.
Recovery and Restoration g.
Adaptive and Evolutionary h.
Recovery and Restoration i.
Recovery and Restoration
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Test your understanding
1 a
2 c
3 b
4 d
5 c
6 c
7 a
8 d
9 d
10 d
11 d
12 d
13 b
14 a
15 c
16 a
17 c
18 b
19 c
20 d
21 Unable to perceive the passing of time, however, we can estimate the time and can wake at a predetermined time.
22 We are aware of some external stimuli.
23 Relinquish control of conscious control of thoughts. Dream when we are asleep.
24 The brain slows down during NREM sleep but is more active during REM sleep.
The brain does not shut down during either stage.
25 The amount of time in REM sleep increases throughout the night.
26 Sleepwalking occurs during Stage 4 sleep.
27 The brain is active and the body is almost paralysed. Hence the paradox.
28 EEG detects, amplifies and records electrical activity in the brain and during
Stage 4 it would show delta brainwave patterns. The EOG detects, amplifies and records electrical activity in the muscles around the eyes and during Stage 4 it would show little to no muscle movement.
29 4–6.
30 The amount of sleep needed decreases as we get older and less time in REM sleep is also required.
31 REM.
32
(i) Recovery and Restoration and Adaptive and Evolutionary.
(ii) Adaptive and Evolutionary: Sleep conserves energy and when asleep the metabolic rate sows. (Hibernating animals.)
Recovery and Restoration: Neurotransmitter adenosine.
(iii) Adaptive and Evolutionary: the assumption that sleep is essential and not necessary and that sleeping is a way to hide from predators (loss of awareness).
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Recovery and Restoration: The assumption that the body rests during sleeping when actually the brain is active.
(iv) Students’ own responses.
Oxford Psychology Units 3 & 4 ISBN 978 0 19 556717 5
© Oxford University Press Australia