Lifespan Changes

Question 1

As humans develop over the years, the nature and function of their sleep changes significantly…

Answer 1

• Follows developmental approach

- Changes through time are recognised, aiding our understanding of ageing on sleep

Question 2

What are some features of infant sleep?

Answer 2

• 16 non continuos hours
• 80% of it is active sleep, an immature version of REM
• Quiet sleep resembles SWS

Question 3

Why is babies sleep non-contiguous?

Answer 3

Sleep cycles are shorter than the adult 90 min cycle

Question 4

When is a circadian rhythm established?

Answer 4

6 months old, where a sleep/wake cycle is settled and REM decreases as SWS increases

Question 5

What is one explanation for why babies sleep for so long?

Answer 5

• Adaptive mechanism so essential chores can be completed

- Nightwaking, small stomachs so need to be fed regularly

Question 6

What is one issue with the evolutionary explanation as to why babies sleep for so long?

Answer 6

• Difficult to prove/disprove so therefore speculative, but would demonstrate a plausible explanation

Question 7

Why might babies spend so long in active sleep?

Answer 7

• Relative immaturity of the brain, need for REM for neurotransmitter dvlpt and consolidation of memories
• REM presents imagery, further stimulating the brain

Question 8

Such ideas for why babies may spend so long in REM links to the biological approach - how?

Answer 8

• Need for biological functions
• Further evidence from Dolphins, born mature, little REM as they do not require further brain development, only fine-tuning

Question 9

How does child sleep differ from that of an infant?

Answer 9

• Matured in terms of growth
• EEG patterns begin to resemble those of an adult
• 12 hours a day spent asleep

Question 10

How much time of a childs sleep is spent in REM?

Answer 10

30%, significantly less than in infants, reflecting increasing maturity

Question 11

What might occur in childhood sleep?

Answer 11

Parasomnias and sleep walking

Question 12

What is adolescent sleep like?

Answer 12

• Average of 9hr sleep
• Circadian rhythms adjust so feel more awake (phase delay), possibly due to SWS hormone release
• Erotic dreams, orgasm and ejaculation

Question 13

How are adolescent sleep patterns different in Korea?

Answer 13

• 6.5 hours of sleep avg, may be attributed to social norms and schoolwork ideals
• May be influenced by external cues rather than internal biology

Question 14

What do findings in Korea highlight?

Answer 14

• Cultural bias of studies into sleep as may only apply to specific cultures
• Limits external validity, may only valid to Western pop

Question 15

What is the nature of adult sleep?

Answer 15

8 hours
25% REM
Increased incidence of sleep disorders (insomnia)

Question 16

What has research into increased sleep in adults found?

Answer 16

• Mortality risk associated with too much sleep

- 1 mil men/women surveyed and those sleeping for over 10 hours had 30% higher chance of death

Question 17

What is important to note with sleep/mortality research?

Answer 17

• based on correlational research
• alternative confounding variables may lay in-between such as geographical location or pre-existing illness
• cannot be certain of cause and effect

Question 18

What is the nature of old age sleep?

Answer 18

• Phase advance
• More frequent wake-ups
• 20% REM
• SWS may be 5% or non-existent due to decreased demand for hormones and repair

Question 19

How can the reduction in sleep in old age be explained?

Answer 19

• Age related health problems such as arthritis

- Less SWS as sleeper is easily disturbed

Question 20

What is an issue with this generalised explanation of why elderly people sleep less?

Answer 20

• Not all elderly people fit this perceived mould
• Some experience more SWS and some will be experiencing better health
• Patterns determined by personal circumstances more so than age alone