Transcript Classical Conditioning

Unit 7: Learning
Behaviorism
• Belief that behavior is learned
– genetics has little to do with it.
• “nurture-only” belief, mainstream1960s and 70s.
• Behaviorists believed learning done through
associations.
• Behaviorists want psychology to be a science:
– observable, testable and measurable.
Attributes of Learning
A. Learning = relatively permanent change in
behavior or knowledge as a result of
experience
B. Distinction between learning and
performance
•
Performance is an exhibited behavior
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Learning can be inferred from performance, but
performance is not always an accurate measure of
learning
C. Learning is adaptive
– Unlike most species whose behavior and
bodies have adapted to a certain environment
– humans have the capacity to learn
– Increase in speed of adaptation in comparison
• Learning and thinking (cognition) have
allowed us to adapt to all environments on
earth, without our bodies changing.
Classical Conditioning
• Ivan Pavlov: Classical Conditioning.
http://www.youtube.com/watc
h?v=nE8pFWP5QDM
Definitions
1. Classical conditioning: learning that takes
place when originally neutral stimulus comes
to produce a conditioned response because
of its association with an unconditioned
stimulus
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In other words – CREATING A REFLEX
2. An unconditioned stimulus (UCS or US)
produces an unconditioned response
(UCR or UR), even in the absence of
previous training
3. A conditioned stimulus (CS) is a stimulus that
has come to elicit a conditioned response (CR)
because the organism associates the
conditioned stimulus with the unconditioned
stimulus
- Initially called the “neutral stimulus”
So let’s go back to Jaws…
Pavlov’s Classical Conditioning:
Pavlovian Response or “Psychic Reflex”
• accidental psychologist: studying digestion initially
• theory links to emotion, temperament, neuroses, and language
Pavlov’s Experiment
Unconditioned vs. Conditioned Responses
• In Pavlov’s demonstration UR = CR
– Salivation
• Although UR and CR consist of same
behavior, there are subtle differences
– CR usually weaker or less intense
• Sometimes UR and CR are different but
related
– Animal given a shock, UR = pain, CR = fear
of imminent pain
Conditioned Reflex
• Classically conditioned
responses described as
reflexes
– Involuntary and automatic
Taste aversions?
Trials
• How long does it take to learn something?
Classical Conditioning Applications
1. Conditioned Fear and
Anxiety
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Phobias
Irrational fear due to
classical conditioning
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Fear of dentist drill
Careful though –
susceptibility of
irrational fear is
mostly based on
genetics… how?
Common Fears based on
association
2. Emotional Responses
– Arousal
• Smell of first love’s cologne/perfume
3. Physiological Responses
• Sexual arousal in quails
– Conditioned to become aroused by nonsexual
stimuli
– Conditioned to elicit increased sperm release
– Fetishes for inanimate objects
• Difficult to test connections to human sexual fetishes
4. Evaluative Conditioning of Attitudes
(evaluative conditioning)
• Changes in the liking of a stimulus that
result from pairing that stimulus with other
positive or negative stimuli
– MARKETING
– http://www.youtube.com/watch?v=pfvq2Gf6U
E8
Volunteers?
B. Acquisition: initial stage of
learning something
1. Involves repeated pairings of the CS and
the UCS/US
2. Acquisition Paradigms (patterns)
• What are the different ways in which the
initial learning can take place?
a. Trace Conditioning
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CS is presented and terminated BEFORE presentation of
the UCS/US
Conditioning often effective when the interval BETWEEN
presentation of the CS
the UCS/US is about a half second
Fear studies; dependent on usage of hippocampus
http://www.youtube.com/watch?v=PsGjh6ul7mE
b. Delay Conditioning
– when CS is presented and continues at least until
the UCS/US is presented
– Often times paired with trace conditioning in studies
– Hippocampus-independent
– Fear expression
Fear Expression in Rats
c. Simultaneous Conditioning
– Occurs when CS and the UCS/US are
presented and terminated at the same time
– Anti-smoking ads
d. Backward conditioning
– Occurs when the UCS/US is presented before
the CS
– http://www.youtube.com/watch?v=fT6IWAIf580
e. Temporal conditioning
– Occurs when the nominal CS is a fixed period
of time between presentations of the UCS/US
– Combined with trace conditioning based on a
period of time
• i.e. dog starts to salivate at 7:59am because s/he
is fed at 8am everyday
C. Extinction
1. A procedure that leads to gradual
weakening and eventual disappearance
of CR
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Involves repeatedly presenting CS without
pairing it with UCS/US
D. Spontaneous Recovery
1. Occurs when previously extinguished CR
suddenly reappears after a period of training
2. Renewal effect
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If a response is extinguished in a different
environment than where it was acquired, the
extinguished response will reappear if the animal is
returned to the original environment where the
acquisition took place
Proves that extinction is a suppression not an
erasure (unlearning)
Explains drug abuse and relapse and difficulty
getting rid of phobias permanently