Download Learning - EVPsychology

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Learning
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Stimulus or Stimuli

Any event or object in the
environment to which an
organism responds
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Learning

Relatively permanent change in behavior, knowledge,
capability, or attitude acquired through experience & cannot
be attributed to illness, injury, or maturation

Why injury? Like when your behavior may change because
you’ve had a brain injury.

Why maturation? Like when you talk in a deeper voice as a
result of puberty.
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Classical Conditioning
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A stimulus comes to predict
the occurrence of another
stimulus and elicits a
response similar to the
response related by that
stimulus.

A cat salivates when they
see and smell their food; tap
the can every time you are
about to feed your cat &
they will start to salivate
when they hear the tapping.
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Ivan Pavlov (1849-1936)

Russian scientist, studied physiology of
digestion, won Nobel Prize in 1904

Major contribution was the study of the
conditioned reflex, which provided a
model of learning called classical
conditioning

Used dogs & a bell
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Elements of Classical Conditioning
Elements


Reflex: an involuntary
response to a particular
stimulus (eyeblink, salivation)
2 kinds of reflexes:
conditioned & unconditioned
OR learned & unlearned
Stimulus & Response

Unconditioned response (UR):
response that is invariably elicited
by the US without prior learning

Unconditioned stimulus (US):
elicits a specific response without
prior learning

Conditioned stimulus (CS): neutral
stimulus after repeated pairing
becomes associated with & elicits a
conditioned response

Conditioned response (CR):
response that comes to be elicited
by a conditioned stimulus as a result
of repeated pairing with US
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Extinction &
Spontaneous Recovery

Extinction: weakening & eventual
disappearance of a learned response

Spontaneous recovery: reappearance of
an extinguished response
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Generalization

In classical conditioning,
the tendency to make a
conditioned response to
a stimulus similar to the
original conditioned
stimulus
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Discrimination

Learned ability to distinguish
between similar stimuli so the
conditioned response occurs
only to the original conditioned
stimulus but not the similar
stimuli
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Higher Order Conditioning

Conditioning that occurs when a neutral stimulus is paired
with an existing conditioned stimulus, becomes associated
with it, and gains the power to elicit the same conditioned
response

For example, Pavlov could flash a light along with the tone he
played & then the light flashing would also become
associated with the stimulus
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John Watson (1878-1958)

Demonstrated that fear could be
classically conditioned by
presenting a white rat along with
a loud, frightening noise, thereby
conditioning Little Albert to fear
the white rat.

Fear generalized to a dog, a seal
coat, Watson’s hair, and a Santa
Claus mask

Formulated techniques to
remove a conditioned fear
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Classical Conditioning:
Modern View

Rescorla: predicting the occurrence of the unconditioned
stimulus

Rat experiment: tone (CS) & shock (US) = predict response
BUT tone (CS) & shock (US) AND no shock (US) = not
predictable response
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Blocking

When previous conditioning to one stimulus prevents
conditioning to a second stimulus with which it has been
paired

Tone (CS), then Light (CS), but tone “trumped” CR because it
was learned first, light (CS) was “blocked”
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Taste Aversions

Intense dislike and/or
avoidance of a particular
food that have been
associated with pain or
discomfort

Can be generalized

Chemotherapy: “scapegoat”
food before treatment
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Everyday Classical Conditioning

Many emotional responses result
from classical conditioning (positive
and negative)

Fears & Phobias / dentist’s office

Drug Use / cues / soldiers & heroin
use in Vietnam
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Advertisements
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Factors Influencing
Classical Conditioning

How reliable a conditioned stimulus predicts the
unconditioned response

The number of pairings of the conditioned stimulus and the
unconditioned stimulus

Intensity of the unconditioned stimulus

Temporal relationship between the conditioned stimulus and
the unconditioned stimulus
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Operant Conditioning

The consequences of behavior are
manipulated in order to increase or
decrease that behavior in the future.

Voluntary responses
(not reflexive)

Active state

Simple to highly complex responses
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Thorndike & the Law of Effect

Edward Thorndike (1874-1949)

Trial-and-error learning: occurs when a
response is associated with a successful
solution to a problem after a number of
unsuccessful responses.

Cats in the puzzle box, hitting lever for food

Law of effect: connection between a stimulus
& response will be strengthened if the
response is followed by a satisfying
consequence or weakened it causes
discomfort.
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B.F. Skinner:
Operant Conditioning Pioneer

Burrhus Frederic Skinner (1904-1990)

Believed behavior was shaped by the
environment

Response first, then consequence

Skinner box: soundproof chamber with a
device for delivering food & either a bar for
rats to press or a disk for pigeons to peck
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Shaping

An operant conditioning technique
that consists of gradually molding a
desired behavior (response) by
reinforcing responses that become
progressively closer to it
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Extinction
 Weakening
& often eventual
disappearance of a learned response
(in operant conditioning, the
conditioned response is weakened by
withholding reinforcement)
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Generalization
In
operant conditioning, the tendency
to make the learned response to a
stimulus similar to the one that was
originally reinforced
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Discriminative stimulus
A
stimulus that signals whether a
certain response or behavior is likely
to be followed by reward or
punishment
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Reinforcement
An
event that follows a response and
increases the strength of the response
and/or the likelihood that it will be
repeated
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Positive Reinforcement
A
reward or pleasant consequence
that follows a response and increases
the probability that the response will
be repeated
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Negative Reinforcement
The
termination of an unpleasant
stimulus after a response in order to
increase the probability that the
response will be repeated
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Primary Reinforcer
A
reinforcer that fulfills a basic
physical need for survival & does not
depend on learning
Eating, sleeping, drinking, stopping
pain, & having sex
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Secondary Reinforcer
A
neutral stimulus that becomes
reinforcing after repeated pairings
with other reinforcers

Money, praise, good grades,
attention, approval
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Continuous Reinforcement


Administered after every desired or
correct response; the most effective
method of conditioning a new
response
Rat got food every time it pressed bar
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Partial Reinforcement

Pattern of reinforcement in which
some portion, rather than 100%, of the
correct responses are reinforced

More like real life, partial
reinforcement is the rule
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Schedule of Reinforcement

Systematic program for
administering reinforcements that has
a predictable effect on behavior
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Distinct rates & patterns of responses
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Fixed-Ratio Schedule


A fixed number of correct responses
Rat receives food after 5 pushes of
lever
What
would happen if the ratio was
100 pushes for each pellet of food?
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If it was 1,000?
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Variable-Ratio Schedule

Reinforcer is given after a varying
number of nonreinforced responses
based on an average ratio

Rat gets food after 30 lever pushes,
then 20 pushes, then 50… averages to
VR of 30

Higher, more stable rates of
responding than fixed-ratio schedules
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Variable-Ratio Schedule

Real life example: Casino gambling
 Variable-ratio: highest
response rate
& most resistance to extinction
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Fixed-Interval Schedule

Reinforcer is given following the first
correct response after a fixed period
of time has elapsed
 Working
on salary: fixed-interval
schedule

Food given every 60 seconds
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Variable-Interval Schedule
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Reinforcer is given after the first
correct response following a varying
time of nonreinforcement based on an
average time.

Pop quizzes, cannot predict, so study
responses should be more uniform
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Partial Reinforcement Effect

Greater resistance to extinction

Reward not expected every time, so the
learning does not become extinct

Strongest resistance to extinction observed
by Holland & Skinner (1961): Fixed ratio of
900, pigeon emitted 73,000 responses during
the first 4 ½ hours of extinction

Why parents should not give into nagging.
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Influencers in
Operant Conditioning

Magnitude

Immediacy

Level of
motivation of the
learner
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Punishment vs.
Negative Reinforcement

Punishment: adds a negative
condition

Reinforcement: removes a negative
condition


Punishment: Discourages a behavior
Reinforcement: Encourages a
behavior
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Problems with punishment

Does not extinguish undesirable
behavior, it suppresses that behavior
when they are being punished

Does not help people develop more
appropriate behaviors

Often causes fear & anger

Can lead to aggression
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Effective Punishments
 Timing
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Intensity
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Consistency
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Escape & Avoidance Learning

Escape learning: performing a
behavior because it terminates an
aversive event (running away, taking
medicine)

Avoidance learning: first, an event
signals a bad situation (classical
conditioning); second, you avoid that
situation (operant conditioning, negative
reinforcement)
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Learned Helplessness


A passive resignation to aversive
conditions learned by repeated
exposure to aversive events that are
inescapable and unavoidable
Dogs; abused women
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Applications
 Training
Animals

Biofeedback
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Behavior modification
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Learning by Insight: Aha!

Wolfgang Köhler (1887-1967)

Chimps, bananas, sticks, boxes &
a flash of insight (not trial-anderror)

Solution gained through insight is
more easily learned, less likely
forgotten & more readily applied to
new problems
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Latent Learning & Cognitive Maps

Edward Tolman (1886-1959)

Latent learning: occurs without
apparent reinforcement but is not
demonstrated until sufficient
reinforcement is provided

Rats, mazes, one rewarded, one not, one
rewarded later.

Cognitive map: mental representation
of a spatial arrangement
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Observational Learning

Albert Bandura (1925-present)

Observational learning or
modeling: learning by watching
the behavior of others & the
consequences of that behavior;
learning by imitation

Fears acquired by observing
behavior

Aggression acquired by
observation