Lifespan changes in
sleep
Techniques used in sleep research
1. EEG (Electro-encephalograph)
This is used to measure electrical activity in the
brain
 Microelectrodes are attached to the patients
scalp to detect electrical activity in specific
parts of the brain.

2. Self Reports
3. Observations of eye movement
New Born Babies
Newborn babies tend to sleep for about
two thirds of the day (16 hrs in every 24).
 They display two kinds of sleep: quiet and
active sleep which are immature versions
of REM and SWS.
 At birth there is more active sleep than
quiet sleep but this gradually decreases.

New born babies AO2….
It has been suggested that babies sleep is an
adaptive mechanism to make the parents lives
easier.
 The greater amount of Active/REM sleep may
be explained in terms of the considerable
learning and brain development that takes
place (Remember from looking at Oswald!).
 It is further supported by the fact that
premature babies (whose brains are very
immature) spend 90% of their sleep time in
active sleep (REM).

One year
Over the first year of life there is a gradual
maturation of sleep EEG patterns so they
begin to look more like adult patterns.
 There is a decrease in active/REM sleep to
about 50% and consolidation of sleep
periods: rather than sleeping in short
bursts, young children sleep through the
night and may have one or two naps
totalling 10-12 hours of sleep.

Five years of age
Full EEG patterns of sleep are shown by the age
of 5, but the frequency is different to adult sleep
patterns: there is more REM sleep (about 33%)
of total sleep time.
 Most children of this age sleep for around 10
hours, boys sleeping slightly more than girls.
 There are more instances of PARASOMNIAS
(sleep disorders), such as sleep walking or night
terrors.

Adolescence
At this age, individuals sleep for an average
of 9-10 hours per night. The amount of REM
sleep is less than in childhood.
 Circadian rhythms also change so that
teenagers feel more awake later at night and
have more difficulty getting up early (a
delayed sleep phase)

Adolescence-AO2
The change in sleep patterns may be linked to
hormonal changes.
 Hormones are generally released at night and so sleep
patterns are disturbed leading to sleep deprivation.
 Hormonal changes can also explain the upset
circadian clock this is described as the delayed sleep
phase syndrome (Crowley et al 2003)
 From this some researchers have recommended that
schools start their day later to accommodate poor
attention spans of adolescents in early morning
(Wolfson and Carskadon 2005)

Old age
REM sleep decreases to about 20% of total sleep time
with a corresponding increase of stage 2 sleep (about
60%).
 The amount of slow wave sleep is also considerably
reduced to as little as 5% and may be non existent for
some older people. (SWS=stage 4, hard to wake
someone in SWS)
 Older people have more difficulty going to sleep and
wake up more frequently (up to six times a night!)
 Older people also experience a phase advance of
circadian rhythms (they feel sleepy early in the
evening and wake earlier in the morning)

Old age AO2:
Reduced sleep in old age is partly a consequence of
Physiological changes (REMEMEBER OSWALD) but
may also be explained in terms of actual problems
staying asleep, such as sleep apnoea or medical
illnesses.
 SWS is reduced in old age and so the older sleep is
more easily woken. The reduction of SWS leads to
reduced production of the growth hormone (because
this is mainly produced in SWS) which may explain
some of the symptoms associated with old age- such
as lack of energy and lower bone density (Van Cauter
et al 2000)

AO2

General comment…… There are significant
individual differences at any age, as well
as cultural differences.
Cultural differences-AO2
Tynjala et al 1993 surveyed 40,000 11-16
year olds from 11 European countries.
 Israeli children = 8.5 hrs on average
 Swiss children = 9.5 hrs on average.
Shin et al 2003 found….
 Korean children = 6.5 hrs on average
 Iranian children = 7.7 hrs on average
Suggests sleep duration is shorter in Asia than Europe
 Most
evidence comes from Lab research
using EEG recordings. These recordings
are obtained by attaching electrodes to
participants. This creates an unfamiliar
sleeping environment which may disrupt
their usual sleep patterns.
 However Empson (1989) suggests that
after the first night participants adjust to
conditions and their sleep is
representative of their usual sleep
patterns