Transcript Classical Conditioning

Classical Conditioning
A. 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
2. An unconditioned stimulus (UCS or US)
reflexively 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
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?
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
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 and 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
– Occurs 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
2. 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