Stimulus

advertisement
Chapter 07
Learning
Module 15: Classical Conditioning
Introduction
Learning
• A relatively permanent change in behavior
due to experience
• Which are examples of learning?
1. The acquisition of language in children.
2. A worm is placed in a T maze. The left side of the maze is
brightly lit and dry; the right side is moist and dim. On the
first 10 trials, the worm turns right 7 times. On the next 10
trials, the worm turns right all 10 times.
3. The cessation of thumb sucking by an infant.
4. A previously psychotic patient is given phrenological
surgery and no longer exhibits any psychotic behaviors.
Stimulus-Response
• Stimulus - anything in the environment
that one can respond to
• Response – any behavior or action
• Example: (S)Someone throws a book at
your head (R) duck, put up
your hands
Classical Conditioning
• A type of learning where a stimulus
gains the power to cause a response
because it predicts another stimulus that
already produces that response
• Form of learning by association
Stimulus-Response Relationship
Stimulus-Response Relationship
Stimulus-Stimulus Learning
Learning to associate one stimulus
with another.
8
Behaviorism
• The view that psychology should restrict
its efforts to studying observable
behaviors, not mental processes.
• Founded by John Watson
Module 15: Classical Conditioning
Components of
Classical
Conditioning
Unconditioned Stimulus (UCS)
• A stimulus that triggers a response
automatically and reflexively
Unconditioned Response (UCR)
• The automatic response to the
unconditioned stimulus
• The relationship between the UCS and
UCR must be reflexive and not learned
Conditioned Stimulus (CS)
• A stimulus that through learning has
gained the power to cause a conditioned
response
• The CS must be a neutral stimulus
before conditioning occurs.
Conditioned Response
• The response to the conditioned
stimulus
• Usually the same behavior as the UCR
Module 15: Classical Conditioning
Ivan Pavlov’s
Discovery
Ivan Pavlov (1849-1936)
• A Russian physiologist who discovered
classical conditioning while doing
experiments on the digestive system of
dogs
Pavlov’s Method of Collecting
Saliva
Pavlov’s Research Apparatus
CLASSICAL CONDITIONING
• TERMINOLOGY
–
–
–
–
Conditioned = Learned
Unconditioned = Unlearned
Stimulus = Causes a response
Response = Behavioral reaction to stimulus
• BASIC COMPONENTS:
–
–
–
–
Natural reflex (automatic, involuntary)
Neutral stimulus – will become conditioned stimulus
Association of stimuli
Timing (0.5 second)
19
Pavlov’s Experiment
Pavlov’s Experiment
Pavlov’s Experiment
The Office
Module 15: Classical Conditioning
Classical
Conditioning
Processes:
Acquisition
Acquisition
• The process of developing a learned
response
• The subject learns a new response (CR)
to a previously neutral stimulus (CS)
Acquisition
Module 15: Classical Conditioning
Classical
Conditioning
Processes: Extinction
and Spontaneous
Recovery
Extinction
• The diminishing of a learned response
• In classical conditioning, the continual
presentation of the CS without the UCS
Extinction
Spontaneous Recovery
• The reappearance, after a rest period, of
an extinguished conditioned response
Spontaneous Recovery
Module 15: Classical Conditioning
Generalization and
Discrimination
Generalization
• Process in which an organism produces
the same response to two similar stimuli
• The more similar the substitute stimulus
is to the original used in conditioning,
the stronger the generalized response
Generalization
Discrimination
• A process in which an organism
produces different responses to two
similar stimuli
• The subject learns that one stimuli
predicts the UCS and the other does not.
Stimulus Discrimination
Discrimination is the learned ability to distinguish
between a conditioned stimulus and other stimuli that
do not signal an unconditioned stimulus.
35
Stop the Carousel I Want to Get Off
• Molly was ecstatic when she learned her family was
going to the state fair next weekend. When her family
arrived at the state fair the temperature was in excess of
100F, but Molly didn't care because she was finally
there. Molly stopped and watched some clowns
performing next to the carousel. As she watched the silly
antics of the clowns with the carousel music playing in
the background, Molly got more and more sweaty and
uncomfortable. Eventually, she fainted from the heat.
After that trip to the state fair, every time Molly hears
carousel music she feels a little dizzy.
• What is the unconditioned stimulus?
• What is the unconditioned response?
• What is the neutral stimulus that becomes the
conditioned stimulus?
• What is the conditioned response?
Stop the Carousel I Want to Get Off
Answers
• unconditioned stimulus: extreme heat
(temperature above 100)
• unconditioned response: fainting
• neutral stimulus / conditioned stimulus:
carousel music
• conditioned response: feeling dizzy
Kitties and Clickers
Psychologists like to experiment on other organisms in their
immediate environment, so Jenny decided to perform a few
experiments on her kitty, Precious. Jenny had a little clicker
that makes a loud ‘CLICK’ sound. She walked around the
house, randomly clicking it for a while while Precious rested in
the living room. Then Jenny sat down with Precious, and used
the flash on her camera to flash a bright light at the same time
she clicked. Precious blinked because of the flash, and looked
mildly annoyed. Jenny repeated this process with her 4 times.
On the 5th time she clicked the clicker, without using the flash.
She still blinked! (She also looked very unhappy).
What is the unconditioned stimulus?
• What is the unconditioned response?
• What is the neutral stimulus that becomes the
conditioned stimulus?
• What is the conditioned response?
Kitties and Clickers
Answers
• unconditioned stimulus: bright flash
• unconditioned response: eye blink
• neutral stimulus / conditioned stimulus:
clicking sound
• conditioned response: eye blink
Module 15: Classical Conditioning
Classical
Conditioning in
Everyday Life:
Little Albert
Little Albert
• 11-month-old infant
• Watson and his assistant, Rosalie
Rayner, conditioned Albert to be
frightened of white rats
• Led to questions about experimental
ethics
Little Albert – Before Conditioning
Little Albert – During Conditioning
Little Albert – After Conditioning
Little Albert - Generalization
Module 15: Classical Conditioning
Classical
Conditioning in
Everyday Life:
Taste Aversion
TASTE AVERSION ACTIVITY:
SOUP
Use a 9 point scale (1 = dislike extremely)
• 1. Stirred by a thoroughly washed, used
flyswatter.
• 2. Flyswatter is brand new.
• 3. Thoroughly washed but used comb
• 4. Thoroughly washed, used dog bowl
47
TASTE AVERSION: FAVORITE
COOKIE
•
•
•
•
5.
6.
7.
8.
Dropped it on the grass first?
A waiter had taken a bite first?
An acquaintance had taken a bite first?
A good friend had taken a bite first?
48
TASTE AVERSION
• The association principle is everything
when it comes to food. Rozin’s results:
• 1. 82% a 4 or less (clean flyswatter)
• 2. 58% disliked (brand new flyswatter)
• 3. 76% disliked (clean, used comb)
• 4. 71% disliked (washed dog bowl)
49
Taste Aversion
•
•
•
•
5.
6.
7.
8.
Only 34% would pass up (grass)
84% reject (waiter)
31% reject (acquaintance)
Just 16% refuse (friend)
50
Taste Aversion and Biological
Predispositions
• Have you ever gotten sick after eating a
particular food?
• How did you feel about/react to the food
after the incident?
• How strong was this feeling/reaction?
• How long did the feeling/reaction last?
51
Taste Aversion
• Subjects become classically conditioned
to avoid specific tastes, because the
tastes are associated with nausea.
• John Garcia (1917- )
Module 15: Classical Conditioning
Cognition and
Biological
Predispositions
Biological Perspective
• We are predisposed to learn things that
affect our survival.
• We are predisposed to avoid threats our
ancestors faced--food that made us sick,
storms, heights, snakes, etc.--but not
modern-day threats--cars, water
pollution, etc.
The End
Download