States of
Consciousness
Unit 3 Psychology
consciousness as the awareness of objects and events in the
external world and the subject’s own existence and activities;
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Consciousness - is the awareness of objects
and events in the external world and of our
own existence and mental processes at any
given moment.
Our state of consciousness – is our level of
awareness of our internal state and external
events, that determines how much of this
information we take in and respond to.
Altered state of consciousness – any state of
consciousness that is distinctly different form
normal waking consciousness in terms of
awareness, sensations, perceptions, thoughts,
feelings and memories.
concepts of normal waking consciousness and altered states of
consciousness, in terms of attention, awareness, content limitations,
controlled and automatic processes, perceptual and cognitive
distortions, emotional awareness, self-control, time orientation;
measurement of physiological responses which can indicate different
states of consciousness, including electrical activity of the brain and
other physiological responses, including heart rate, body temperature
and galvanic skin response;
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EEG - An electroencephalograph measures that
amplitude and frequency of brain wave patterns.
Beta, alpha, theta and delta waves.
Heart rate – In some ASCs heart rate increases,
while in others it decreases.
Body temperature – changes during some ASCs
eg. It drops by more than 1 degree during sleep.
Galvanic skin response – measures the electrical
conductivity of the skin. Electrode are placed on
the hands. Increased sweat = increased
electrical conductivity, a low level of sweat =
decreased electrical conductivity. High emotional
arousal (often experienced in an ASC) results in
increased sweating.
methods used to study sleep electroencephalogram (EEG),
electromyograph (EMG), electrooculogram
(EOG eye movements);
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Electroencephalograph (EEG) – detects,
amplifies and records brain waves.
Electromyograph (EMG) – detects, records
and amplifies electrical activity of muscles.
Progressive reduction of muscle tension
through stages 1-4
Electro-oculargram (EOG) – detects, records
and amplifies electrical activity of muscles
that control eye movements. Minimal eye
movement in NREM and rapid eye movement
in REM
characteristics and patterns of sleep: rapid eye movement
(REM sleep), non-rapid eye movement (NREM) sleep;
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Naturally occurring biological rhythm
An ASC
Two main types:
- Non rapid eye movement (NREM) sleep
- Rapid eye movement (REM) sleep
Periods of NREM sleep alternate with periods
of REM sleep about 4-5 times during a night
As sleep progresses:
- Periods of NREM sleep get shorter
(particularly stage 3 & 4)
- Periods of REM sleep get longer and closer
together
Dreams occur more in REM sleep
NREM Sleep
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80% of the full sleep cycle is spent in NREM
sleep.
A full cycle of NREM lasts about 70 to 90
minutes and is followed by a period of REM
sleep.
During the cycle a person moves through
stages 1-4 and back up to the early stages
again before entering REM sleep.
The four stages of NREM progress from
lightest to deepest sleep and can be identified
by their brain wave patterns.
Before stage 1 begins a transition from being
awake to entering the first stages of sleep
occurs. This is known as the ‘hypnogogic
state’ where the person may experience
flashes of light or slow rolling eye movements.
REM Sleep
Sleep state
Deep sleep (difficult to wake)
Brain waves
Beta (like those of an awake, active
person)
Heart rate
Relatively fast
Breathing rate
Relatively fast and irregular
Muscle tension
No muscle tone (completely relaxed;
virtual paralysis - atonia)
Eye movements
Rapid, jerky
Main Feature
Dreaming. 85% of dreams occur here.
Periods of REM get longer as the night
progresses.
Also called paradoxical sleep – brain is extremely active
while the body has no muscle tone/tension and appears
inactive and calm.
NREM Sleep – Stages 1-4
Characteristic
Sleep state
Brain waves
Heart rate
Breathing
rate
Muscle
tension
Body
temperature
Stage 1
Stage 2
Stage 3
Stage 4
Drifting in &
out of sleep
Light sleep
(true sleep
begins)
Moderately
deep sleep
Deep sleep
Alpha and
theta
Theta. Sleep
spindles & Kcomplex
Theta then
some delta
Delta
Irregular
Slower & more regular
Slow & regular
Irregular
Slower & more regular
Slow & regular
Lower in muscle tension
Relaxed (low
muscle tension)
Relatively
tense
(hypnic jerk)
Normal
Progressively lower
Lowest
psychological and physical effects of sleep deprivation;
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Going without sleep partially or totally.
Effects depend on the amount of sleep loss and the
period of time over which it occurred.
Normally has temporary effects such as irritability,
tiredness, lack of concentration, headaches and
slower reaction time. All of the effects can be
overcome with sleep.
If excessive or prolonged deprivation occurs it can:
 Cause hallucinations and delusions
 Impair performance on simple, monotonous tasks
 Complex or interesting tasks- performed normally
Hard to study for more than 3 days as people drift
into microsleeps – very short period of sleep when
the person is apparently awake. (brain waves =
early NREM sleep)
Psychological & Physiological effects of sleep deprivation
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Psychological – lack of concentration, irritability,
moodiness, heightened anxiety and lack of
motivation. Short term memory can be
significantly impaired. Depression,
hallucinations, delusions and paranoia have also
been reported. A reduced ability to perform
cognitive tasks that are monotonous and boring
is also a concern. More errors are made on
simple tasks than complex ones.
Physiological – sleepiness and fatigue, hand
tremors, drooping eyelids, lack of energy,
slurred speech and an increased sensitivity to
pain. After 5 consecutive days and nights, heart
rate falls, respiratory rate slows, biochemical
changes occur and hallucinations may be
experienced.
sleep phenomena, including insomnia, hypersomnia, sleep apnoea,
nightmares, night terrors, sleep walking, sleep talking;
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A sleep disorder is any problem that disrupts the
NREM or REM sleep cycle.
Insomnia – ongoing experience of insufficient or poor
quality sleep due to:
 Difficulty falling asleep or (sleep onset insomnia)
 Difficulty staying asleep (sleep maintenance
insomnia)
 Awaking prematurely from sleep
Caused by:
 Psychological factors (stress, anxiety) or
 Physiological factors (chronic pain, illness)
Treatment:
 Medication or re-establishing sleep patterns
 Diet/activity
Sleep Disorders – Sleep Apnoea & Hypersomnia
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Temporarily stop breathing when asleep (20
secs to 2 mins)
Occurs repeatedly throughout the night and
terminates in a loud snore, body sitting
upright or limbs flinging out.
Cause:
 Failure of breathing centres in brain
 Narrowing of the airway –excess fat
Treatment – relaxants for throat or nose or a
nasal mask to force oxygen down the throat
at night.
HYPERSOMNIA
 Sleepiness/drowsiness when awake
 Excessive sleeping (eg. 12 hours per night
for an adult)
Sleep Phenomena
Characteristic Nightmare
Night
terror
Sleep Walking
Sleep
Talking
Nature
Recall on
awakening
Unpleasant
dream
Sudden
awakening
extremely
distressed
Walking during
sleep (may
perform routine
activities)
Verbalisation
during sleep
Yes
Very little
Rarely
Rarely
REM
NREM stage
3&4
NREM stage 3 &
4
Any NREM
stage
No
Yes
Yes
Sometimes
Sleep period
Bodily
movement
research designs used to minimise the effects of extraneous
variables, including repeated measures design, matched–
participants design, independent–groups design;
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There are 3 experimental designs that may reduce or eliminate EVs.
Repeated Measures Design: is an experiment where the same
group of participants makes up both groups (experimental and
control) in the experiment. Advantages: minimal differences in
personality characteristics between the two groups and fewer
participants are required for the study. Limitations: Order effects –
this occurs when prior knowledge of a task/situation influences the
performance participant and therefore the results of the experiment.
Matched Participants Design: is when participants are paired up
or ‘matched’ on the basis of personality characteristics. One
member of the pair or ‘match’ is then assigned to the control group
and the other member is assigned to the experimental group. Twins
are often perfect for this type of design. Advantages: Provides two
very similar groups. Limitations: Time consuming to arrange.
Independent Groups Design: is the most common experimental
design. Each participant is randomly allocated to one of the two
groups. Advantages: There are no order effects to control, and it is
quick to set up. Limitations: Equally sized groups are often difficult
to achieve with a small sample size.
Experimental Design
Independent
Groups Design
Participants are
randomly allocated
to either the
experimental of the
control group.
Matched Pairs
Design
Participants are
‘matched’ as pairs on
the basis of relevant
variables; one of the
pair is allocated to
the experimental
group, the other to
the control group
Repeated
Measures Design
The same Participants
are used in both the
experimental and
control group.
placebo effects, experimenter effects, single blind and
double blind procedures;
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A placebo is a fake pill or injection. The Placebo effect
is when changes in occur in behaviour of a participant
due to the belief that they have taken a drug. Eg. A
saline injection can be 70% as effective as morphine
when given as a placebo.
A single blind procedure can be used to control for
placebo effects. The participants are simply not told
(are blind) as to whether they are in the control group
(given the placebo) or in the experimental group (given
the real drug).
The experimenter effect refers to changes that occur in
participants’ behaviour that are caused by the
unintended influence of an experimenter.
A double blind procedure can be used to control for
experimenter effects. In this procedure, neither the
experimenter or the participant knows who has received
the placebo (control group) and who has received the
real drug (experimental group). This keeps the
experimenters from unintentionally influencing the
participants.
ethical principles in the conduct of psychological research
related to sleep
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See Page 347 – 350