Download Real-Life Examples of Classical Conditioning

Document related concepts

Learning theory (education) wikipedia , lookup

Neuroeconomics wikipedia , lookup

Applied behavior analysis wikipedia , lookup

Verbal Behavior wikipedia , lookup

Behavior analysis of child development wikipedia , lookup

Behaviorism wikipedia , lookup

Psychological behaviorism wikipedia , lookup

Eyeblink conditioning wikipedia , lookup

Psychophysics wikipedia , lookup

Classical conditioning wikipedia , lookup

Operant conditioning wikipedia , lookup

Transcript
Chapter 5
Ivan Pavlov
Ivan Pavlov (1849-1936)
 Pavlov, a Russian
physiologist, first
described classical
conditioning in 1899 while
conducting research into
the digestive system of
dogs.
 He was particularly
interested in the role of
salivary secretions in the
digestion of food and was
awarded the Nobel Prize
for Medicine or Physiology
in 1904.
Pavlov’s Research
 Pavlov used an apparatus
to measure the amount
of saliva produced when
a dog ate.
 The flow of saliva
occurred naturally
whenever food was
placed in the dog’s
mouth, as salivation is an
involuntary, reflex
response.
Pavlov’s Method
 Dog was restrained in a harness
to avoid extraneous variables.
 Meat powder was placed directly
on the dog’s tongue or in the
bowl.
 A tube was surgically attached to
the dog’s cheek near one of the
salivary glands and a fistula was
made so that the saliva drained
straight out into a measuring
device.
 Further on, more sophisticated
measuring devices were used to
measure the speed of saliva flow.
What did Pavlov observe?
 Pavlov observed that the dogs
 A stimulus is any event or
salivated not only at the sight of
the food, but also at the sight or
sound of the lab tech who had
been preparing the food.
 Pavlov was intrigued by these
unintentional observations & he
decided to conduct further
experiments.
 His subsequent experiments
provided clear evidence of a
form of learning based on the
repeated association of 2
different stimuli.
object that elicits a response
from an organism.
 A response is a reaction by an
organism to a stimulus. In
Pavlov’s experiment, the
stimulus of food initially
produced the response of
salivation.
 Eventually the sight or sound of
the tech became the stimulus.
How is this response explained?
 The salivation response
 This process is in essence
is controlled by the
autonomic division of
the PNS.
 Involuntary.
 The salivation had
become associated with,
and conditioned to, a
new stimulus – the lab
tech.
the process of classical
conditioning.
What is Classical Conditioning?
 Also known as respondent
conditioning refers to a
form of learning that
occurs through the
repeated association of 2 or
more different stimuli.
 Learning is only said to
have occurred when a
particular stimulus
consistently produces a
response that it did not
previously produce.
 In classical condition, a
response that is
automatically produced
by one stimulus becomes
associated, or linked,
with another stimulus
that would not normally
produce this response.
There are 4 key elements that are used to describe the process of
classical conditioning.
1. Unconditioned Stimulus
 The unconditioned
stimulus (UCS) is any
neutral stimulus that
consistently produces a
particular, naturally
occurring, automatic
response.
 In Pavlov’s experiment,
the UCS was the food
(meat powder).
2. Unconditioned Response
 The unconditioned
response (UCR) is the
response that occurs
automatically when the
UCS is presented.
 A UCR is a reflexive,
involuntary response
that is predictably
caused by a UCS.
 In Pavlov’s experiments,
the UCR was the
salivation.
3. Conditioned Stimulus
 The conditioned stimulus
(CS) is the stimulus that is
neutral at the start of the
conditioning process and
does not normally produce
the UCR.
 Yet, through repeated
association with the UCS,
the CS triggers a very
similar response to that
caused by the UCS.
 Association refers to the pairing
or linking of 1 stimulus with
another stimulus.
 In Pavlov’s experiments, the bell
and subsequently other stimuli
were initially neutral, but each
became associated with the
meat powder.
 Once conditioning has occurred
and the originally neutral
stimulus produces the response
of salivating, then it is called the
CS.
4. Conditioned Response
 The conditioned response
 Pavlov’s dogs displayed a
(CR) is the learned
response that is produced
by the CS.
 The CR occurs after the CS
has been associated with
the UCS.
 The behaviour involved in
a CR is very similar to that
of the UCR, but it is
triggered by the CS alone.
CR (salivation) only when
they began to salivate to a
CS.
 When the dog responded
to a CS, such as the sound
of a bell, classical
conditioning had taken
place because salivation
would not be a usual
response to the sound of a
bell.
Another example…
https://www.youtube.com/watch?v=hhqumf
pxuzI
https://www.youtube.com/watch?v=OwBQI
hg6CvE
Pavlov distinguished several key processes that are involved in
classical conditioning. These are known as:
•Acquisition, extinction, stimulus, generalisation, stimulus
discrimination and spontaneous recovery.
Acquisition
 Each paired presentation
of the CS with UCS is
referred to as a trial.
 Acquisition is the overall
process during which the
organism learns to
associate 2 events.
 The rate of learning is
often very fast in the early
stages of the acquisition
phase.
 Timing of the CS and UCS
pairing is critical.
 Pavlov found that a very short
time between presentations of
the 2 stimuli was most effective.
 Acquisition is more rapid when
the CS occurs and remains
present until the UCS is
presented.
 The end of the acquisition stage
is said to occur when the CS
alone produces the CR.
Extinction
 A conditioned stimulus-
 E.g. Pavlov’s dogs eventually
response association can fade
over time or disappear
altogether.
 Extinction is the gradual
decrease in the strength or rate
of a CR that occurs when the
UCS is no longer presented.
 Extinction is said to have
occurred when a CR no longer
occurs following presentation of
the CS.
ceased salivating (CR) in
response to the bell (CS)
presented alone after a number
of trials in which the food (UCS)
did not follow the sound of the
bell).
 There is some variation between
individuals in the rate at which
extinction of the same
conditioned response will occur.
 There is also considerable
variation between the rates at
which different response will be
extinguished.
Spontaneous Recovery
 Extinction of a CR is not
 Spontaneous recovery
always permanent.
 In CC, spontaneous
recovery is the
reappearance of a CR
when the CS is
presented, following a
rest period after the CR
appears to have been
extinguished.
does not always occur
and when it does it is
often short-lived.
 Furthermore the CR
tends to be weaker than
it was originally.
Stimulus Generalisation
 Pavlov observed that his dogs
salivated to other noises that
sounded like a bell.
 This is known as stimulus
generalisation which is the
tendency for another stimulus to
produce a response that is similar to
the CR.
 The greater the similarity between
stimuli, the greater the possibility
that a generalisation will occur.
 E.g. is a stimulus generalisation to
the sounds of a bell occurred with
one of Pavlov’s dogs, the dog might
also salivate in response to the
ringing of the front-door bell.
 However, the amount of saliva
produced by the dog would tend to
be less than the amount produced
by the original bell to which the dog
was conditioned.
Stimulus Discrimination
 Stimulus discrimination occurs
when a person or animal
responds to the CS only, but not
to any other stimulus that is
similar to the CS.
 E.g. in a CC experiment,
stimulus discrimination would
be observed when a dog
salivated only in response to the
sound of the ‘experimental bell’,
and not in response to any other
similar sound such as a door
bell.
Experimental Neurosis
 Ability of the dog to discriminate between the shapes
 Circle (CS) was accompanied by feeding (UCS)and
salivation (CR and UCR) was measured.
 When Ellipse was introduced dog did not salivate still
salivated at the circle.
 When ellipse was made to closely resemble circle
discrimination disappeared
 It created emotional reactions in the dogs such as
restlessness, frustration-because of lack of control and
predictability
EXAMPLES OF CLASSICAL CONDITIONING
Using electric wires to keep
cows in a field
- Electric shock
- Jump back
- wire
- Stay away
EXAMPLES OF CLASSICAL CONDITIONING
Using electric wires to keep
cows in a field
UCS
- Electric shock
UCR
- Jump back
CS
- wire
CR
- Stay away
ELECTRIC CAN OPENER / CATS
- food
- Run into the kitchen
- Or sound of opening
the can or can opener
- Run into the kitchen
ELECTRIC CAN OPENER / CATS
UCS
- food
UCR
- Run into the kitchen
CS
- Or sound of opening
the can or can opener
CR
- Run into the kitchen
Real-Life Examples of Classical Conditioning
Mowrer & Mowrer (1938) Treatment for enuresis (bed-wetting)
-Child sleeps on a pad (a wire mesh that is connected to a bell has been sewn)
- Child wets the bed  electrical circuit causes bell to ring (UCS)
-Child wakes up (UCR)
After several repetitions of this cycle (bed-wetting causes him to
be awakened by the bell), the child begins to associate the
sensation of pressure in his bladder (a previously neutral stimulus)
with waking up
-In a short time, the need to urinate (now a CS) becomes
sufficient in itself to awaken the child (now a CR) so he or she can
get up and go to the bathroom - no need for PAD with Bell
Real-Life Examples of Classical Conditioning
Gustavson and Gustavson (1985) – Conditioned Taste Aversion
Coyotes killing sheep – problem to sheep farmers
Study conditioned coyotes not to eat the sheep
Sheep meat sprinkled with a chemical that would produce a stomachache
After coyotes ate the treated meat,
they avoided the live sheep
This humane application of conditioned taste aversion might be used to
control other predators as well
Real-Life Examples of Classical Conditioning
Gustavson and Gustavson (1985) – Conditioned Taste Aversion
Coyotes killing sheep – problem to sheep farmers
Study conditioned coyotes not to eat the sheep
Sheep meat (CS) sprinkled with a chemical (UCS) that would produce a
stomachache (UCR)
After coyotes ate the treated meat,
they avoided the live sheep (CR)
This humane application of conditioned taste aversion might be used to
control other predators as well
Real-Life Examples of Classical Conditioning
Metalmikov & Chorine (1926, 1928) – Immune System
Injected Guinea Pigs with Foreign agents (non lethal)
 antibodies  boost their immune system
Then paired injections with Lights
Lights + Injections = better immunity
Lights alone = better immunity
Later Injected Cholera: animals with prior conditioning
better survival vs controls with no conditioning
In A Clockwork Orange, a brutal sociopath, a
mass murderer, is strapped to a chair and
forced to watch violent movies while he is
injected with a drug that nauseates him. So he
sits and gags and retches as he watches the
movies. After hundreds of repetitions of this,
he associates violence with nausea, and it limits
his ability to be violent.
Conditioned Emotional
Response
 An emotional reaction such as
fear of a specific stimulus is
learned through CC.
 A conditioned emotional
response is an emotional
reaction that usually occurs
when the autonomic nervous
system produces a response to a
stimulus that did not previously
trigger that response.
 E.g. fearing the sound of the
dentist’s drill.
Founder of Behaviorism:
Only study behavior…not concerned with the mind…focus on
relationship between environment and behavior
VH1 “Behind the Science”
-Born South Carolina
-Wild & impulsive
-Trouble with law
-16 yrs – to college
-21 yrs – masters
-Supported himself totally
through college
-4th year turned in a paper back to front – “F”
-Grad school – Univ. of Chicago
-Ph.D. in 3 years
-1907 offered position - Johns Hopkins $2500
-1915 APA President (37 yrs)
“Little Albert” – first CC in humans
"Give me a dozen healthy infants, wellformed, and my own specialized world to
bring them up in, and I'll guarantee to
take any one at random and train him to
become any type of specialist I might
select – doctor, lawyer, artist, merchant
chief and yes, even beggarman and
thief, regardless of his talents, penchants,
tendencies, abilities, vocations and race
of his ancestors.”
Watson’s ‘Little Albert’
experiment
 American psychologist John B.
Watson and his graduate
student, Rosalie Rayner first
used CC to elicit an emotional
response.
 Aim to test the notion that fears
can be acquired through CC.
 The research participant was
Albert B. (Little Albert), the 11
moth old son of a woman who
worked at the same clinic as
Watson.
How was Little Albert
conditioned to hate the rat?
 They placed him on a
mattress in a room where a
white lab rat (CS) was
within reaching distance.
 Albert showed no initial
fear of it and played with
it.
 They then struck a
hammer on a steel bar
behind Albert (loud noise,
UCS) and Albert began to
cry.
 For the next 17 days
Watson and Rayner began
a series of fearconditioning experiments.
 They also conducted tests
to find out if Albert’s fear
response could be
generalised.
 Albert also seemed to fear
a white rabbit, a dog and a
seal skin coat.
During Conditioning
(Association & Acquisition)
CS
Is associated with
Which automatically
leads to the
UCS
UCR
After Conditioning
CS
Leads to a
conditioned
response
CR
Ethical considerations?
 Albert’s mother left her job and
 Informed consent is not
Watson and Rayner reported
that they were denied the
opportunity to remove the
conditioned emotional
responses.
 This has been disputed, as it is
believed they were aware of
Albert’s departure a month in
advance.
 Some believe Albert’s mother
may not have been fully aware of
the experimental condition and
effect on her son.
mentioned in Watson original
article, so a judgement cannot
be made about this ethical issue.
 Also possible that Albert was
vulnerable to psychological
harm as a result of the
experiments.
 Yet Albert was subjected to
severe anxiety and distress & the
experimenters made not
attempt to end the experiment
and attend to his distress in an
appropriate way.
Never Published again…Private Industry
CC is used in a range of different settings, many of which are
concerned with therapeutic benefits. These include:
Aversion therapy and systematic desensitisation.
Elimination of Motivated
Behaviours
 Counterconditioning
 Negative CS paired with
positive UCS by no longer
paired with negative UCS.
 e.g removes phobias
….ghost movies
Elimination of Motivated
Behaviours
 Developed on the 1950s by
 The client associates being
psychiatrist Joseph Wolpe,
systematic
desensitisation is a kind
of behaviour therapy that
attempts to replace an
anxiety or fear response
with a relaxation response
through a classical
conditioning procedure.
relaxed with the anxiety or
fear-arousing stimulus by
means of a series of graded
steps.
 Basic principle is that the
client is gradually
desensitised to anxiety or
fear-arousing objects,
activities or situations.
Wolpe’s procedure:
Person is taught to
relax.
2. Break down the fear
arousing situation into
a logical sequence of
steps (steps are ranked
from least to most fearinducing).
1.
 Case study: fear of flying.
Most frightening
•Experiencing mid air
turbulence
•Taking off
•Taxiing down the runway
•Boarding the plane
•Waiting to get on the plane
•Travelling to the airport in a
car
•Buying a place ticket.
Least frightening
Procedure cont…
 Once the steps are ranked,
 The best results seem to
the therapist then teaches
the person deep muscle
relaxation and asks them
to imagine the least
frightening scene on the
list and so on…
 In the end the person
learns to imagine the most
frightening scene without
becoming afraid.
occur using real life
desensitisation, such as the
therapist sitting in a plane
with the person or
introducing them to the
pilot for reassurance.
 By allowing the client to
confront the phobia under
such supportive
circumstances, the fear of
flying is eventually
overcome.
Interoceptive Conditioning
 Razran (1961) CS, UCS, or both are applied to internal
organs
 Intero-exteroceptive conditioning: CS is applied
internally UCS is applied externally
 Intero-interoceptive conditioning: CS and UCS applied
internally
 Extero-interoceptive conditioning: external CS paired
with an internal UCS
Learned Aversions
 A taste-aversion is a conditioned
 This tends to happen with one
response that results from a
person or animal establishing an
association between a particular
food and being or feeling ill after
having consumed it at some
time in the past.
 The association is usually the
result of a single experience &
the particular food will be
avoided in the future.
 There is an association between
a CS( smell/taste of food) and
the UCS (nausea producing
substance).
trial.
 One-trial learning is a form of
learning involving a change in
behaviour that occurs with only
one experience.
Garcia’s
st
1
Experiment
 Thirsty rats were allocated to 1 of
 Rats who had flavoured water
2 experimental groups.
 Whenever rats in 1 group licked
the tube, a bright light was
flashed and a clicking noise
sounded (bright –noisy
condition).
 Rats in the other condition were
offered saccharine-flavoured
water to drink from a tube.
 Later, rats in one group received
a painful shock to their feet,
while those in the other group
received a dose of illnessinducing X-rays.
and X rays avoided the water.
 Rats in the shock group did not
associate shock with water.
 Rats in bright noisy condition
did not develop aversion to
water as a result of X ray.
 But had the rats learned to avoid
all parts of the CS, or just some
of them? (CS – combo of
saccharine flavoured water,
bright light and clicking noise).
Garcia’s
nd
2
Experiment
 Tested same rats under a
 Result: rats that had
different condition.
 The rats were given
either saccharineflavoured water that was
not paired with either
light or noise, OR
unflavoured water that
was paired with the same
light and noise that had
been present during the
previous condition.
become ill because of the
effects of the X-rays
avoided the saccharine
flavour, but were quite
content to drink water
accompanied by the
same light and noise.
 In general, results
indicate the UCS
influenced what the rats
had learned.
Learned aversions
 Biological constraints-predisposition to learn certain
associations
 Prepared associations-reflexes
 Contraprepared associations-cannot learn
 Unprepared associations-can be learnt
Learned Aversions in Cancer
 Progressive Muscle Relaxation
 Guided Imagery
 Anxiety, nausea, and vomiting
IntroductionInstrumental/Operant
Conditioning  Thorndike and his
puzzle boxes
Freddie!
 Coined the phrase




‘Operant conditioning’
The animal operates on the
environment
Unlike ‘respondent
conditioning’ (Pavlovian)
Pioneered the use of free
operants
Pioneered the use of
respone rate
The Skinner Box
 Basically this allowed
the researcher to walk
away
 Allowed for a
dependent variable
that could be easily
measured and
compared across
species too
Criticisms of the Skinner box
 Is it artificial?
 Well duh…
 But
 Many species can be tested
 Real world applications
 Therapy
 Who cares?
Instrumental Conditioning
Pavlovian Conditioning = Stimulus learning
Instrumental Conditioning = Response learning
Instrumental behavior = behavior that occurs
because it was previously instrumental in
producing certain consequences
Also called ‘goal-directed’ behavior
Instrumental Conditioning
Thorndike interpreted the results of his experiment
as reflecting the learning of an S-R association
Thorndike believed the cats learned an association
between the stimuli inside the puzzle box and the
escape response
The consequence of the successful response – escaping
the box – strengthened the association between the box
stimuli and that response
On the basis of his work, Thorndike formulated
the law of effect
Quantity, Quality, and Contrasts
of Reinforcement
 Crespi’s rat experiment (1942)
 AOR: positive association between reinforcement
(reward) and performance
 QOR: Quality of reinforcement
 Negative contrast
 Positive contrast
 History of reinforcement
 Latent learning
Reinforcers
Increases the probability that response will occur
 Primary Reinforcers-More innate linked to basic
needs
 Secondary Reinforcers-Acquired through
experience-money, status etc
 Generalized conditioned reinforcers-gains
reinforcing properties through pairing with primary
reinforcers
Schedules of Reinforcement
 Fixed Interval
 First response after a
given interval is
rewarded
 FI Scallop
 Variable Interval
 Like FI but varies with a
given average
 Scallop disappears
Schedules of Reinforcement
 Fixed Ratio
 Reinforcement is given
after a given number of
responses
 A little less smooth
 Variable Ratio
 After a varying number
of responses
Reinforcement
 Occurs when a stimulus change immediately follows a
response and increases the future frequency of that type
of behavior in similar circumstances
 Reinforcement can also strengthen the duration, latency,
magnitude, and/or topography of behavior
 How immediate?
 The behavior closest in time to the reinforcer will be
strengthened
 When behavior is affected by a delayed consequence,
language is probably playing a role and not simply
reinforcement
Positive Reinforcement
 Occurs when a behavior is followed immediately by
the presentation of a stimulus that increases the
future frequency of the behavior in similar conditions
 Positive reinforcer: a stimulus whose presentation
or onset functions as reinforcement
Negative Reinforcement
 Occurs when a behavior is followed immediately by
the removal, termination, reduction, or
postponement of a stimulus that increases the future
frequency of the behavior in similar conditions
 Negative reinforcer: a stimulus whose termination
or reduction functions as reinforcement
 Can be unconditioned (e.g., pain) or conditioned
(e.g., dirty look)
 Note: Negative Reinforcement is not punishment!
 https://www.youtube.com/watch?v=Mt4N9GSBoMI
Applications
 Work with autistic kids
 Prompts
 Fading
 Secondary reinforcers
 Token economies
 I/O applications
 Behaviour therapy
Token Economies
 “Tokens” considered currencies or credit
 Given in exchange for appropriate behavior
Classical-Operant Interactions
 Acquired Fear
 Conditioned Emotional Responses
 Stimuli associated with positive emotional or
motivational states.
Learned Helplessness
 A typical case of demotivation
 Symptoms-Passivity, retardation of learning, somatic
effects, reduction of helplessness with time
 Causes & prevention–lack of control and depression
Observational Learning
 Vicarious learning/Modelling-learned through
observation
 Self reinforcement-self regulation of behavior
 Modelling process
 Attention
 Retention
 Reproduction
Classical Conditioning &
Aggression
 Pain & Aggression (Ulrich & Azrin, 1962)
 Pairing neutral stimulus with pain = Aggression
Instrumental Conditioning &
Aggression
 Reinforcing or rewarding aggressive behavior
 Modelled aggression
 https://www.youtube.com/watch?v=Pr0OTCVtHbU
 Vicarious reinforcement
 Observing rewards and punishments of a particular
behavior will alter the probability of performing the
modeled behavior

Act that is punished is less likely to be performed!
Sexual Motivation & Learning
 Classical conditioning shows a role in sexual learning
in animals and humans!
 Mate preferences are learned early in life!
 Previous sexual experience influences copulation!
 Role of Culture: Sexual values
 Who is selected as mates
 What age is appropriate
Sexual Motivation & Learning