States of Consciousness: Consciousness and the TwoTrack Mind Ch. 3
 Before the turn of the last century Psychology was concerned
primarily with ‘the description and explanation of states of
consciousness’
 Because of problems associated with studying directly and
measuring consciousness, the focus of Psychology changed to
the study of observable behaviour (behaviourism).
 Since behaviour is directly observable, it can be measured and
changes in behaviour can be attributed to intervening processes
such as learning
 Behaviourism has been the predominant influence in North
American Psychology during the past century
 During the last part of the century, however, interest rekindled
in studying states of consciousness (response to the limitations
of behaviourism)
 Today, contemporary psychology is concerned with both the
study of behaviour as well as with the study of consciousness.
What is consciousness?
 Today, we define consciousness as:
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awareness of ourselves and our environment
a process which allows us to exert voluntary control over
ourselves
a way of communicating mental states
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 We direct our consciousness through attentional mechanisms
 Consciousness consists of several levels or layers
 We can obtain some insight into how the conscious mind works
by looking at how humans perform certain types of tasks
 When we first engage in a task like driving a car, our conscious
mind focuses on variables such as the traffic, pedestrians, the
operation of the vehicle, the feel of the car on the road, etc.
 As we become more practiced at driving, the task becomes more
automatic and requires less conscious effort (skilled
behaviour).
 Becoming a skilled performer leads to the conscious mind
becoming less and less burdened by the task
 The task becomes under the control of subconscious processes
 This freeing up the conscious mind allows us to parallel process
e.g. daydreaming, reading while driving the car
 When behaviour becomes skilled, the conscious mind is free to
monitor behaviour, do other things and to deal with novel
situations
 Therefore, less familiar tasks and situations require more
conscious effort or attention
 This division of labour (conscious / unconscious) is seen as a
way that allows our mind to use it’s resources more efficiently
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Normal and altered states of consciousness
Normal – when we are awake, how we usually see the world, hear,
reason and remember
Altered states – sleep, dreams, daydreams, hypnotic states,
chemically induced states, near death experiences (NDE’s).
Sleep
 We spend approximately 1/3 (25 years) of our lives asleep
 Why do we sleep?
 Sleep helps us assimilate newly learned information
 During sleep, the body releases growth hormones – sleep
is particularly important for young growing bodies
 Sleep rejuvenates our bodies and promotes recovery of
our immune system
 Our tendency to sleep at night may have helped to keep
us out of harms way from predators (Coren)
 Studies looking at sleep deprivation in animals show that they
will eventually die from lack of sleep – for a long time,
however, autopsies could not identify any specific physiological
causes of death
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 More recently, it has been discovered that the lack of sleep leads
to decreased efficiency of the immune system and that sleep
deprivation will cause the immune system to shut down and
eventual lead to death.
How much sleep do we need?
 we need on average about 10 h of sleep per 24 h period
 it may not be necessary to have this much sleep in one session –
many societies formalize afternoon rest periods, the Spanish
refer to as Siesta
 Evidence for needing 10 h of sleep is based on comparative
psychology studies (chimps and other primates) and on summer
arctic studies conducted by UBC
Sleep Rhythms
 Sleep has its own rhythm
 Each night we experience 5 stages of sleep, which cycle every
90 min
 Other animals have different lengths to their sleeping cycles and
sleep for very different lengths of time (e.g. horses 4 h)
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Stage 1:
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Irregular EEG patterns
Light sleep
Lasts about 2 minutes
Can experience fantastic images
Feelings of expanding and contracting
Feelings of falling, weightlessness
Sudden jerks
Stage 2:
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Deeper sleep
Lasts about 20 min
EEG shows rapid bursts of rhythmic brain activity –
called sleep spindles
During Stage 2, people sometimes sleep talk but the talk
is garbled nonsense speech
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Stage 3:
 Transitional sleep
 Lasts only a few minutes
 Brain starts to generate Delta waves (slow, high
amplitude synchronous firing of neurons)
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Stage 4:
 Lasts about 30 min
 Characterized by a lot of Delta waves – brain activity is very
rhythmic
 Strangely enough, this is when sleep walking occurs, also when
children tend to wet the bed
 Also, when a truck goes by, person may not wake up but a
babies cry will wake us up – this suggests a selective filtering of
information and possibly even a biological/genetic
predisposition to respond to select frequencies of sound
REM (rapid eye movement) or paradoxical sleep
 After being asleep for about an hour, we return to Stage 1,
through Stages 2&3
 We spend ½ of our sleep per night in stages 2&3
 When we enter REM – increase in HR, breathing becomes rapid
& irregular, rapid eye movements about every 30 s
 REM period lasts up to 30 min
 If woken up, dreams are remembered – REM not the only time
we dream but dreams are extremely vivid and often have a
surrealistic quality to them with lots of symbolic meaning
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 During REM, motor cortex is very active but brain stem blocks
activity to the body and the body is extremely relaxed and
immobilized
 80% of people who claim that they don’t dream remember
dreams if they are woken up during REM
 If someone is deprived of REM, there is a rebound effect in
subsequent sleep
Biological Rhythms and Sleep
 In addition to sleep having its own 90 min biological rhythm,
overall sleep is regulated by biological rhythms we call
circadian rhythms (24h cycles)
 Sleep is regulated by 2 types of biological rhythms –
endogenous and exogenous rhythms
 Endogenous rhythms are the stronger of the two and are
controlled by an internal body clock (RAS), but are calibrated or
adjusted by means of exogenous time cues
 Endogenous rhythms control body functions including core
temperature and metabolism
 Exogenous rhythms are rhythms controlled by external time
givers (Zeitgbers) – light/dark being prominent but social cues
(dinner time) also act as external time givers.
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 Endogenous rhythms change to 25 h cycles in the absence of
exogenous time cues – cave studies, flying across time zones,
night shifts
 If we fly across time zones and try to sleep according to new
light/dark cycle, we have problems sleeping until exogenous
cues recalibrate endogenous rhythms
 Easier to fly from east to west than west to east
 Ideally people will adapt (re-entrain) to a night shift but it rarely
happens
 Easier for people to adapt to shifts that rotate forward
 We need to sleep when body temperature is falling in order to
experience proper sleep periods
 If exogenous cues continue to change, temperature rhythms
flatten out – once this happens, deep sleep can’t be obtained
 Deep sleep is critical for our bodies to recuperate
 Estimates are that a lifetime of work causing flattened body
temperature rhythms will decrease life expectancy by up to 20%
Sleep Debt
 Because we need 10 h of sleep our 24 h society suffers from
sleep debt (Coren)
 Daylight savings/ single car accident studies (spring forward –
lose 1 h increase accidents by 7%)
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 Cost of sleep debt in the US is estimated between 3 and 4
hundred billion dollars per year (accidents, decreased work
efficiency, absenteeism)
Lack of sleep:
 Impairs creativity & concentration and vigilance (consciousness
and attention)
 Mood changes – irritability
 Tremor
 Slowed performance (blocking)
 Misperceptions on monitoring tasks (vigilance and attention)
 Cherynobl, Exon Valdez, 3 Mile Island, Challenger, Bopal
 All monitoring tasks, people who have been working the night
shift, accidents around 3:00 AM.
Sleep Disorders
 Newborns sleep about 16 h per 24 h
 Adults sleep 7.5 h per 24 h
Insomnia
 Difficulty getting to sleep – affects 10-15% of the population
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 Quick fixes such as sleeping pills or alcohol reduce REM and
leave the person feeling tired the next day
 Best strategies are:
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Relax before bed
Avoid caffeine within 5 h of sleep
Drink milk – helps produce serotonin
Sleep according to a regular cycle
Avoid naps
Don’t eat before bed
Restrict sleep time
Narcolepsy
 Falling asleep uncontrollably – regularly overcome with the
need to sleep – affects 1 in 1000
 Extremely dangerous condition
Sleep apnea
 breathing stops while asleep
 affects 1 in 25
 decrease in blood oxygen levels arouse sleeper
 condition often associated with snoring – excessive weight
(peripheral sleep apnea)
 condition can also be brainstem dysfunction (central sleep
apnea)
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Dreams
 REM dreams are more vivid, emotional and bizarre than dreams
experienced during other stages of sleep
 Manifest content - the story line - often follows events
experienced during the day
 Latent content – meaning of the dream – according to Freud,
our unconscious adjusting our psyche through experience
 Information processing, assimilation and learning
Hypnosis
 An altered state related to subconscious mind
 Subconscious brought forward – conscious mind put into
suspension (dissociation)
 Some people are more susceptible than others
 Harvard Hypnotic Susceptibility Scale
 Hypnosis can help with some memory problems and with the
alleviation of pain
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Drugs
Psychoactive:
 Alter states of consciousness
 Depressants - calm neural activity, slow CNS
 Stimulants - excite neural activity, arouse CNS
 Hallucinogens – evoke sensory images without stimulation
Depressants:
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Inhibition of inhibition
State dependency
Degrade performance and judgment
Alcohol reduces self awareness
Opiates – brain stops producing endorphins – pain on
stopping, REM rebound from heroin withdrawal and
nightmares
Stimulants:
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Stimulate CNS – sympathetic
Increases energy and self confidence
Improves performance
Weight loss
Keeps people awake – alert
Hallucinogens:
 PCP (angel dust)
 LSD
 Generation of internal stimulation
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 Marijuana – short term memory effects, decreasing dose
response, stored in fatty tissue for up to 30 days
Near death experiences:
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Light
Tunnel
Helpers
Common across cultures
other
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