Download Classical Conditioning

GENERAL PSYCHOLOGY II
Dr. Albina Colden
[email protected]
GENERAL PSYCHOLOGY II
1.
A (re-)introduction to Psychology
2.
Quantifiable Responses: Behaviourist Learning
. sensitization
. habituation
. classical conditioning
. operant conditioning
3. The Mental World: Cognition
. schema theory
. priming, framing, and “subliminal processes”
. cognitive dissonance and the drive for coherence
. self-awareness, intent, and free will: an illusion?
4. Memory
. memory systems
. memory processes
neurological
& biological
processes
mental
processes
social
processes
developmental
processes
Motivation
Attention
Perception
Emotion
Cognition
Learni n g
Memory
Behaviour
Personality
Abnormality
Neuropsychology
Biological
Psychology
Cognitive
Psychology
Social
Psychology
Psychology
of Emotion
Memory
Behaviorism
Individual
Difference s
CrossCultural
Psychology
Developmental
Psychology
BEHAVIORIST LEARNING
BEHAVIORIST LEARNING
Q What is Behaviorist Learning?
How is it different from other
types of learning?
BEHAVIORIST LEARNING
Q What is Behaviorist Learning?
How is it different from other types of
learning?
A Behaviorist Learning is…
•
focused on external behaviour
•
focused on the “prediction and control” of behaviour
•
quantitative and quantifiable
•
physiological / neurological (not cognitive)
•
automatic (happens regardless of intent)
•
not limited to human beings; can take place in any life form
The Birth of the Term “Behaviourism”
John B. Watson
John Broadus Watson, a godfather of American behaviorist psychology, tests grasp reflex in a baby, circa 1916-20.
(Courtesy Johns Hopkins University Archives/From "World as Laboratory„)
The Birth of the Term “Behaviourism”
John B. Watson
published article:
"Psychology as the Behaviorist Views It " (1913)
(sometimes called "The Behaviorist Manifesto." )
In this article, Watson outlined the major features of his new
philosophy of psychology, called "behaviorism."
Watson‘s idea of behaviorism emphasised external behavior rather
than the internal, mental state
The analysis of behaviors and reactions = the only objective method
to get insight in the human action.
The Birth of the Term “Behaviourism”
John B. Watson
"Psychology as the Behaviorist Views It " (1913)
Psychology as the behaviorist views it is a purely objective
experimental branch of natural science. Its theoretical goal
is the prediction and control of behavior. Introspection forms
no essential part of its methods, nor is the scientific value of
its data dependent upon the readiness with which they lend
themselves to interpretation in terms of consciousness. The
behaviorist, in his efforts to get a unitary scheme of animal
response, recognizes no dividing line between man and
brute. The behavior of man, with all of its refinement and
complexity, forms only a part of the behaviorist's total
scheme of investigation.
The Birth of the Term “Behaviourism”
John B. Watson
Behaviourism (1930)
Give me a dozen healthy infants, well-formed, and my own
specified 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, merchantchief and, yes, even beggar-man and thief, regardless of his
talents, penchants, tendencies, abilities, vocations, and
race of his ancestors. I am going beyond my facts and I
admit it, but so have the advocates of the contrary and they
have been doing it for many thousands of years.
BEHAVIORIST LEARNING
I. Simple Learning (non-associative)
. Sensitisation
. Habituation
II. Associative Learning
. Classical Conditioning
. Operant Conditioning
BEHAVIORIST LEARNING
Simple Learning: Sensitization
repeated stimulation causes progressive amplification
of a response
Example:
Rubbing your arm continuously will cause
repeated stimulation of peripheral nerves
this stimulation will first create a warm sensation,
then will gradually become painful.
pain is the result of progressively amplified synaptic response of the
peripheral nerves
biological function of this: to warn that the stimulation is harmful.
BEHAVIORIST LEARNING
Simple Learning: Sensitization
3 types of Sensitization:
long-term potentiation (gradual buildup)
kindling (sudden crossing over a thresh-hold)
central sensitization (peripheral nerve response
spreads centrally to cause overall
sensation)
BEHAVIORIST LEARNING
Simple Learning: Sensitization
Examples of Sensitization:
•
•
•
•
•
Allergies
Drug addiction
Pain hypersensitivity
Orgasm
Seizure
! long-term potentiation, kindling, or central
sensitization?
BEHAVIORIST LEARNING
Simple Learning: Habituation
Progressive diminishing of behavioural response with
repetition of a stimulus
The orientating response makes us initially react to a
stimulus.
But, if it is neither rewarding nor harmful, then subsequent
responses are reduced.
Habituation has been shown in essentially every species of
animal
occurs through neural adaptation in sensory nerves
themselves and through negative feedback from the
brain to peripheral sensory organs
BEHAVIORIST LEARNING
Simple Learning: Habituation
Examples of Habituation
Touch: feeling your clothing on your skin: the sensation eventually
disappears
Smell: walking into a smelly environment, and at first thinking it is
unbearable – then getting used to it and not even being able
to smell it any longer.
Taste: Something that initially tastes too sweet (or salty), but
gradually begins to taste normal
Sight: we gaze less and less at a particular visual stimulus the
longer it is presented.
Sound: being initially distracted by a noisy environment, but then
getting used to it and no longer even really hearing the sound
BEHAVIORIST LEARNING
Simple Learning: Habituation
Habituation Curve
BEHAVIORIST LEARNING
Simple Learning: Habituation
Habituation Curve
Habituation depends on:
. time between presentations of stimulus
. similarity of stimuli
(identical versus similar or familiar)
BEHAVIOURIST LEARNING
Associative Learning
. Classical Conditioning
BEHAVIOURIST LEARNING
Associative Learning
. Classical Conditioning
“VIP”s:
Pavlov
Watson
Classical Conditioning:
Ivan Petrovich Pavlov
Classical Conditioning:
Ivan Pavlov
In the 1890s, Pavlov was investigating the salivary glands of dogs
externalised the salivatory gland in order to collect and analyze
salivatory response to food under different conditions.
In performing these experiments, Pavlov noticed that the dogs
tended to salivate before food was actually delivered to their
mouths
decided to investigate this "psychic secretion“ instead of his
previously planned research
changed the focus of his research, carrying out a long series of
experiments in which he manipulated the stimuli occurring before
the presentation of food.
Classical Conditioning:
One of Ivan Pavlov‘s Experimental Dogs
Classical Conditioning:
One of Ivan Pavlov‘s Experimental Dogs
Classical Conditioning:
Ivan Pavlov
established the basic laws for the establishment and
extinction of what he called "conditional reflexes" - reflex
responses, like salivation, that only occurred conditionally
upon specific previous experiences of the animal.
Experiments carried out int he 20s
signaled the occurrence of food by ringing a bell. However,
his writings record the use of a wide variety of stimuli,
including electric shocks, whistles, tuning fork, and a range
of visual stimuli, in addition to ringing a bell.
Classical Conditioning:
Ivan Pavlov
Classical Conditioning:
Ivan Pavlov
Terminology
NS: Neutral Stimulus
US: Unconditioned Stimulus
UR: Unconditioned Response
CS: Conditioned Stimulus
CR: Conditioned Response
Classical Conditioning:
Classical Conditioning in Humans:
John B. Watson
The “Little Albert” Study
a well-known (infamous) experiment
demonstrating classical conditioning in humans
Classical Conditioning in Humans:
John B. Watson
The “Little Albert” Study
chose the baby Albert B. from a hospital for this
study at the age of nine months
Albert was the baby of an employee at John
Hopkins University, where John B. Watson did his
research
Classical Conditioning in Humans:
John B. Watson
The “Little Albert” Study
Before the commencement of the experiment, Little Albert
was given a battery of baseline emotional tests; the infant
was exposed, briefly and for the first time, to a white rat, a
rabbit, a dog, a monkey, masks with and without hair, cotton
wool, burning newspapers, etc.
During these baseline tests, Little Albert showed no fear
toward any of the items.
Classical Conditioning in Humans:
John B. Watson
The “Little Albert” Study
:)
experiment began by placing Albert on a mattress on a table in the
middle of a room.
white laboratory rat was placed near Albert and he was allowed to
play with it.
At this point, the child showed no fear of the rat. He reached out to
the rat and made pleased noises as rat roamed near him.
Classical Conditioning in Humans:
John B. Watson
The “Little Albert” Study
+ BANG!!
:(
In later trials, Watson and Rayner made a loud sound behind
Albert's back by striking a suspended steel bar with a hammer
when the baby touched the rat.
During these trials, Little Albert cried and showed fear as he heard
the noise.
Classical Conditioning in Humans:
John B. Watson
The “Little Albert” Study
:(
After several such pairings of the two stimuli, Albert was again
presented with only the rat.
Now, however, he became very distressed as the rat appeared in
the room. He cried, turned away from the rat, and tried to move
away.
Albert now associated the white rat with the loud noise and was
producing a conditioned fear response
RAT (NS)
-->
--
NOISE (US)
--> FEAR (UR)
(natural response in infants)
RAT (CS)
NOISE (US)
--> FEAR (UR)
RAT (CS)
--> FEAR (CR)
Classical Conditioning in Humans:
John B. Watson
The “Little Albert” Study
:(
Side-effect: Little Albert seemed to generalise his
response to other stimuli, not just the white rat:
gray rabbit, furry dog, a fur coat, Santa Claus mask with
white fluffy beard
Classical Conditioning in Humans:
John B. Watson
The “Little Albert” Study
Watson and his colleagues had planned to extinguish these
fearful reactions in Little Albert at the end of the experiment
(pair the white rat with warm milk which babies love).
However, Albert left the hospital on the day these last tests
were made, and this did not took place
Nothing is known of Albert's later life.
Classical Conditioning:
Generalization
When the CR occurs not only to the specific CS
that was learned, but also to other stimuli with
similar characteristics
In the case of Little Albert, he became
conditioned to respond with fear not only to the
white rat, but also to “fluffy things in general”
Classical Conditioning:
Extinction
extinguishing of the conditioned response (CR),
after repeated presentation of conditioned
stimulus (CS) without the appearance of the
unconditioned stimulus (US)
The CR grows weaker and weaker when it is no
longer paired with the US
Classical Conditioning:
Extinction
US
-->
UR
CS
US
-->
UR
CS
-->
CR
CS
-->
CR
CS
-->
--
Classical Conditioning:
Extinction
CS
-->
CR
CS
-->
CR
CS
-->
CR
CS
-->
CR
CS
-->
CR
CS
-->
Classical Conditioning:
Latent inhibition
exposure to a stimulus alone prior to conditioning trials
slows or prevents conditioned associations with that
stimulus being formed.
Classical Conditioning:
Latent inhibition
NS
NS
NS
NS (now becomes CS)
US
--> UR
NS will have difficulty becoming a CS and evoking a CR
CS -- > CR? (maybe, but more trials will be needed)
Classical Conditioning:
Learned inhibition
A conditioned stimulus-response relationship can
overpower a naturally occuring (unconditioned ) stimulusresponse relationship
Classical Conditioning:
Learned inhibition
Example: mice and anxiety (Kandel & Pollak)
mice conditioned to associate safety with a sound
When they hear this sound, they experience less anxiety
even in stressful situations that would normally evoke high
anxiety
Classical Conditioning:
Blocking Effect (Kamin, 1969)
conditioning to a stimulus could be blocked if the stimulus
were reinforced in compound with a previously conditioned
stimulus.
Classical Conditioning:
Blocking Effect (Kamin, 1969)
US --> UR
CS1
US --> UR
CS2
CS1
US --> UR
CS1 --> CR
CS2 --> --
Classical Conditioning:
Preparedness (Martin Seligman, 1970)
associative learning is not an arbitrary process;
the ease with which associations can be formed depends on biological
predispositions shaped by the specialised evolutionary history of a
species.
Classical Conditioning:
Preparedness (Martin Seligman, 1970)
an organism can be either:
. prepared,
. nonprepared, or
. contraprepared
for associative learning.
Preparedness is a predisposition to learn an association rapidly;
Nonpreparedness is the neutral middle of the preparedness
continuum, where the associations to be learned are acquired neither
rapidly nor slowly;
Contrapreparedness is the opposite pole, where an animal learns an
association only with great difficulty.
Classical Conditioning:
Preparedness
selectivity of association in species:
certain birds locate food by its visual characteristics,
rather than by its taste, like rats
Wilcoxin et al (1970)
Trained rats and quail
Taste + Visual quality paired with poison --> illness
Classical Conditioning:
Preparedness
Wilcoxin et al (1970)
Rats and Quail:
Blue Sour Water (CS)
Poison (US)
--> Illness (UR)
which aspect of the water was trained as the CS?
the blue colour or the sour taste?
Classical Conditioning:
Preparedness
Wilcoxin et al (1970)
Rats and Quail:
Blue Sour Water (CS)
Poison (US)
--> Illness (UR)
RATS:
Sour Water (CS)
--> Illness (CR)
QUAIL:
Blue Water (CS)
--> Illness (CR)
Classical Conditioning:
Preparedness (Martin Seligman, 1970)
Seligman extended his preparedness thesis to human fears and
phobias.
Human fears appeared to be "(1) selective, (2) ... resistant to
extinction, (3) irrational, and (4) capable of being learned in one trial."
(1971, p312) and non-cognitive.
links this preparedness to evolutionary origins, pointing out that the
great majority of phobias are about objects of ecological importance to
the survival of the species (e.g. fear of darkness, fear of dangerous
animals such as snakes and spiders).
Classical Conditioning:
Preparedness (Martin Seligman, 1970)
Oehman & Dimberg (1979; 1985)
McNally (1987)
used slides of snakes and spiders as conditioned stimuli
and paired them with electric shock as the unconditioned
stimulus.
Conditioning to these stimuli was then compared with
conditioning to stimuli such as slides of houses, flowers,
and mushrooms.
BEHAVIOURIST LEARNING
Associative Learning
. Operant Conditioning
BEHAVIOURIST LEARNING
Associative Learning
. Operant Conditioning
“VIP”s:
Thorndike
Skinner
Operant Conditioning:
Edward L. Thorndike (1874-1949)
Operant conditioning, sometimes called instrumental
conditioning or instrumental learning
observed the behavior of cats trying to escape from homemade puzzle boxes.
When first constrained in the boxes, the cats took a long
time to escape.
With experience, ineffective responses occurred less
frequently and successful responses occurred more
frequently, enabling the cats to escape in less time over
successive trials.
Operant Conditioning:
Edward L. Thorndike
Cats In Puzzle Boxes
Thorndike's Puzzle Box Procedure
Thorndike placed a hungry cat inside a "puzzle box" with
food outside. Initially, the cat would become agitated and
produce many different "random" behaviours in an attempt
to get out of the cage. Eventually, the cat would press the
paddle by chance, the door would open and the cat could
escape and get the food. The cat would then be placed
inside the box again and would again take a long time (on
average) to escape after exhibiting many different
behaviours.
Operant Conditioning:
Edward L. Thorndike
Cats In Puzzle Boxes
Thorndike's Puzzle Box
Thorndike examined the time to escape (his operational
definition of learning) as a function of trials. The learning
curve was gradual and uneven (see below). There was
little evidence of sudden insight. Nevertheless, after about
thirty trials, the cats would press the paddle almost as
soon as they were placed in the cage. Thorndike
concluded that the animals learned by "trial and error".
Operant Conditioning:
Edward L. Thorndike
Law of Effect
successful responses, those producing satisfying consequences, were
"stamped in" by the experience and thus occurred more frequently.
Unsuccessful responses, those producing annoying consequences,
were stamped out and subsequently occurred less frequently.
Result: some consequences strengthened behavior and some
consequences weakened behavior.
Operant Conditioning:
Edward L. Thorndike
Law of Effect
Learning Curve
Thorndike produced the first known learning curves
through this procedure.
Operant Conditioning:
Edward L. Thorndike
Law of Effect
Learning Curve
Operant Conditioning:
Edward L. Thorndike
Operant Conditioning:
Factors that alter the effectiveness of consequences
1. Satiation: the appetite/desire for the result must be strong (cat
needs to want to get out of the box!).
2. Immediacy: result must happen immediately after the desirable
action in order for it to become cnditioned.
3. Contingency: the result must follow the action reliably and
consistently
4. Size: The size, or amount/degree of the result must be significant
enough to be worth the effort
Operant Conditioning:
Burrhus Fredric Skinner (1904-1990)
B.F. Skinner formulated a more detailed analysis of operant
conditioning based on reinforcement, punishment, and extinction.
operant conditioning is:
The learning process through which the consequence of
an operant response affects the likelihood that the
response will be produced again in the future.
Unlike reflexes (in classical conditioning), operant
responses are voluntary actions. In operant learning,
the emphasis is on the consequences of a motor act
rather than the act in and of itself.
Operant Conditioning:
Burrhus Fredric Skinner (1904-1990)
Operant Chamber (“Skinner Box”)
Skinner box is a cage with a lever or some other mechanism
that the animal can operate to produce some effect, such as the
delivery of a small amount of juice.
allowed to measure rate of response as dependent variable using a
cumulative record of lever presses or key pecks
Operant Conditioning:
B. F. Skinner (1904-1990)
Three Consequences of Behaviour
1) Positive Reinforcement: stimulus that increases the probability of a behaviour
(access to fish as positive reinforcer for a cat).
2) Negative Reinforcement: stimulus whose removal increases the probability of a
behaviour. For example, bar pressing that turns off a shock.
3) Punishment: stimulus whose presence (as opposed to absence) decreases the
probability of behaviour. For example, bar press that leads to a shock.
Skinner thought that punishment was the least effective of the 3 possible
consequences for learning.
Operant Conditioning:
Avoidance learning
Avoidance training is part of negative reinforcement. The subject
learns that a certain response will result in prevention of an aversive
stimulus.
Example: Dog & Shuttle-box
Operant Conditioning:
Learned Helplessness
When the negative reinforcer (punishment) arrives
regardless of action taken, the creature/individual soon
stops trying, gives up
When dog in shuttle-Box
experiment cannot predict shocks,
it simply gives up and remains in
the same place despite being
continuously shocked.
Once this effect occurs, it is very
difficult to reverse, even if shock
patterns become predictable again.
Operant Conditioning
Examples in Humans
Humans can be conditoned to “perform” behaviour by being reinforced
for those behaviours:
- positive reinforcers: smiling, food, gambling, affection
- negative reinforcers: withholding of smiling, food, affection
- punishments: frowning, crying, pain
Experiment: “The Operant Conditioning of Human Motor Behavior”
Verplank (1956)
showed that even a socially/emotionally neutral stimulus that was
described as a “reward” (“getting a point”, which had absolutely no value
outside the experiment) could shape human behaviour
Operant Conditioning
Examples in Humans
Experiment: “The Operant Conditioning of Human Motor Behavior”
Verplank (1956)
Operant Conditioning
Examples in Humans
Experiment: “The Operant Conditioning
of Human Motor Behavior” Verplank (1956)
. Participants were told that when the experimenter taps a pencil, this means they
“earn 1 point”
. There were no rules or explanations regarding what behaviour would cause this
earning of points, only that the pencil tap would indicate it
. After pre-determining the behaviour that he wanted to condition, the experimenter
tapped his pencil whenever he saw the participant engage in this behaviour (for
example, touching his face, or tapping his foot)
. With time, the participant began to unconciously engage in the desired behaviour
more and more frequently
. Participants did not report being aware of which of their actions caused them to earn
points; they would perform the actions automatically and unconsciously
Behaviourist Conditioning in Humans?
Is it possible? Is it effective? Is it ethical?
BEHAVIORIST LEARNING REVIEW
Sensitisation
long-term potentiation
kindling
central sensitization
Habituation
habitution curve
Classical Conditioning
NS / US / UR / CS / CR
Pavlov (dogs)
Watson (Little Alfred)
generalisation
extinction
inhibition (latent & learned --> mice experiment)
preparedness (rats/ quail blue sour water experiment)
BEHAVIORIST LEARNING REVIEW
Operant Conditioning
Thorndike (cat in puzzle box)
Law of effect
Learning curve
Skinner (rats & pigeons)
Positive reinforcement
Negative reinforcement
Avoidance learning
Punishment
Learned helplessness