Transcript Chapter 5 - Angelfire

Chapter 5
Learning
How do people learn?
What is learning?
• Many different theories exist- including:
– Constructivism
– Behaviorism
– Piaget’s Developmental Theory
– Neuroscience
– Brain-based Learning
– Learning Styles
– Multiple Intelligences
– Right Brain/Left Brain Thinking
Cont.
– Communities of Practice
– Control Theory
– Observational Learning
– Vygotsky and Social Cognition
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In the everyday sense, learning often refers to
formal methods of acquiring new knowledge
or skills, such as learning in the classroom or
learning to play a flute.
According to psychologists…
• The topic of learning is much broader.
• Psychologists formally define learning as a
process that produces a relatively
enduring change in behavior or knowledge
as a result of an individual’s experience.
• According to psychologists, learning
occurs in every setting not just in the
classroom.
Cont.
• Learning takes place at every age.
• The psychological study of learning is not limited
to humans. Learning is an important aspect of
behavior of virtually all animals.
• Much of our knowledge of learning has been
discovered by behaviorists, psychologists who
believe that only observable behavior is a valid
topic for study.
Behavior Analysts- Who are they?
• Behaviorists (psychologists) who practice
behavior modification and change
behavior by working with the environment
• Most behavior analysts work with
developmentally disabled children or
patients in psychiatric hospitals
• Other behaviorists help people to end bad
habits like smoking or overeating
How do behaviorists study
learning?
They observe the learning experiences of animals
in carefully controlled laboratory situations
Using animals as subjects, researchers can
precisely control the conditions under which a
particular behavior is learned
• Conditioning: a very basic form of learning; the
process of learning associations between
environmental events and behavioral responses
Conditioning and learning
• Answering the phone and using a wordprocessing program- are behaviors we
have learned through conditioning
• Two types of conditioning:
– Classical conditioning
– Operant conditioning
The Father of Classical
Conditioning
• The psychological study of learning began in
Ivan Pavlov’s Russian laboratory in the late 19th
century- he was initially studying the digestion
process in dogs
• Pavlov became interested in how the
presentation of food automatically produced
salivation
• To explain this phenomenon-Pavlov invented a
teaching technique: classical conditioning
• Pavlov taught dogs to salivate at the sound of a
bell- how is this classical conditioning?
Try it.
• Think about something really tasty and
see if your mouth waters automatically.
Did it work?
• It should because salivation is a reflexive
response to food. It is the body’s way of
preparing to receive food. Saliva helps
break down food into digestible bits.
Classical Conditioning
• Organisms first display a response to a stimulus
that they do not have to be taught, something
they do “naturally”
• Ex: Dogs salivate naturally when they are fed
• In his study, Pavlov taught dogs to salivate at the
sound of a bell that signaled that food was
coming
• Often involves reflexive behavior( a relatively
simple, unlearned behavior governed by the
nervous system, that occurs automatically when
the appropriate stimulus is presented)
Pavlov: 4 Components of classical
conditioning:
#1:
Occurs Before conditioning:
• Unconditioned responses (UR): Pavlov’s
dogs automatically, or reflexively, salivated
when presented with food. They didn't
have to learn or be conditioned to salivate
in the presence of food. Pavlov called this
response unconditioned- or not-learned.
Unconditioned stimuli (US)
• #2. Occurs During conditioning
• An event that automatically triggers a
certain reflex reaction is called an
unconditioned stimuli.
– Ex: food in the dog’s mouth was the US
– Salivation for the food was the unconditioned
response (UR).
Conditioned stimuli (CS)
• #3. A conditioned stimuli is an event that
is repeatedly paired with the unconditioned
stimulus. The bell that Pavlov rang in a
typical experiment = CS
• It was conditioned or associated with food
through the process of pairing trials. The
idea is that after enough trials, the CS will
produce the desired response on its own.
Conditioned responses (CR)
• #4. Occurs After conditioning
• Once the Conditioned Stimuli produces
the Unconditioned Response on its own,
the desired response is called the
conditioned response.
• this is a learned reaction
• Ex- the dog hears the bell and salivates
even when food is not present
Confused?
• Classical conditioning terminology can be
confusing~ think of the term conditioned
as having the same meanings ‘learned”
• “conditioned stimulus” refers to “learned
stimulus”
• Unconditioned response” refers to
“unlearned response”
Factors that affect conditioning
Pavlov discovered that many factors could affect
the strength of the conditioned response:
ex. The more frequently that the conditioned and
unconditioned stimulus were paired, the stronger
the association between the two
Intermittent pairing: pairing the CS and US only
once in a while, reducing both the rate of
learning and the final strength of the learned
response
Extinction
• The pairing of two appropriate stimuli stops and
the power of the CS eventually fades
• If the CS is presented enough times without the
US, the CS will eventually cease to elicit the CR
• This reverses the process of classical
conditioning
• Example: Pavlov’s dogs learned to salivate at
the sound of a bell- if the bell keeps getting
presented without any delivery of food, the dogs
would eventually stop salivating at the sound of
the bell.
Why is classical conditioning
important?
• Very important in terms of human survival
• It helps us to learn things by association
without effort
• After we have associated a CS with a US
to the point where the CS produces the
CR, we can expand automatically on that
learning through a process known as
generalization.
Generalization
• Ex. If you learn to associate certain facial
gestures, like a snarl or a sneer, with
eventual violence, then the snarl/sneer
(CS) produces fear (CR) whereas only a
flying fist of a verbal threat (US) elicited
fear (UR) in the past.
• You have generalized and this could save
your neck.
Generalization, cont.
• On the negative side…
• If attacked by a black pit bull, you might get
scared any time you encounter a black dog,
even a Chihuahua
• OR- Consider a war veteran who suffers from
post-traumatic stress. If this person has
experienced loud explosions and heavy gunfire
and developed a strong fear to these events, this
individual may react the same way when they
hear a car backfire or some other loud noise.
Discrimination
• When we begin to over-generalize what
we’ve learned, we are not engaging in
discrimination. We need to know how to
discriminate, or tell the difference
between stimuli- between a gun firing and
a car backfiring.
• Discrimination is learned when a CS is
presented enough times without eliciting a
response.
Classical Conditioning in Humans
• As common in humans as it is in animals- ex.
Phobias: intense, irrational fears of particular
things or situations- spiders, snakes, flying,
heights, claustrophobia
• John Watson and Baby Albert
• Joseph Wolpe: (psychiatrist) desensitization
therapy- treatment for anxiety – believes it was
not possible to be both fearful and relaxed. If
people wee taught to relax in fearful situations,
anxiety should disappear.
Operant Conditioning
• Learning in which an important event
follows a specific response
• The important event is a positive
consequence
• ex. Every two weeks I get paid at my job.
Am I paid to sit around and take up
space? No, I’m paid for performing duties,
for working. I do something and something
happens. I work, and I get paid.
• Operant conditioning takes place all
around us, in our homes, as well as the
workplace. Parents use rewards, or
operant conditioning to get their children to
do their homework.
Edward Thorndike: Law of Effect
• 1911
• Addressed the idea of a consequence
having an effect on behavior
• Subject: Cats
• Constructed the puzzle box made out of a
wooden crate with spaced slats and a door
that could be opened by a special
mechanism
• Placed a hungry cat inside the box and
shut the door.
• Placed some food on a dish outside the
box and the cat could see it through the
slats in the crate.
• The cat had to figure out how to open the
door to get the food.
• Cat accidentally hit the latch and the door
opened- cat got to eat.
• Tried it again- at first the cat didn’t recall how he
had triggered the latch. Eventually the cat
triggered the latch again- each time he tried it,
the cat found the latch in shorter amounts of
time.
• The greater the satisfaction, the greater the
strengthening of the bond. The consequence of
getting the food served as a reward for learning
how to open the box. The opening the box
behavior = my job; the food was like my
paycheck.
Reinforcer
• When a consequence of an action or
event increases the probability that the
event or action will happen again- it is
being reinforced
• Like a reward
• Operant conditioning is all about the
effects that reinforcers have on behavior
B.F. Skinner
• Famous behavioral psychologist, followed
Thorndike in using animals to investigate
operant conditioning.
• Skinner Box: constructed a box with a lever
inside- when an animal pressed the lever, a food
pellet fell out of a feeder into the box
• Skinner wanted to see if rats placed in the box
could learn to press the lever in order to receive
the food.
• Rats aren’t used to pressing levers- Skinner had
to facilitate the process with a procedure known
as shaping.
• Skinner rewarded the rats for performing a
behavior that was close to the required
response.
• Shaping was done gradually so that the rats
pressed the bar for food the same way that
Thorndike’s cats learned to open the door.
Conclusion
• Anything that increases the likelihood that
a behavior will occur again can be used a
reward or reinforcer.
• The reinforcer could be food, money,
recess, or vacations.
Types of Reinforcers
• Two basic types of reinforcers:
– Positive reinforcement is the use of any
reinforcement that increases the likelihood
that a behavior will occur again.
– Negative reinforcement occurs when the
removal of noxious stimuli leads to an
increased likelihood that a behavior will occur
again.
Are all reinforcers equal?
• Probably not…differences between
reinforcers exist and determine the impact
that the reinforcers have on responses.
• Two types of positive reinforcers:
– Primary reinforcers: rewards that do not
require shaping or prior training to be
effective. Ex. food, pleasurable sensations,
water, adequate warmth
Cond.
• Conditioned reinforcer: also called a
secondary reinforcer, is one that has
acquired reinforcing value by being
associated with a primary reinforcer.
• Ex. Money: reinforcing because we have
learned that we can use it to acquire
primary reinforcers and other conditioned
reinforcers. Also, awards, frequent-flyer
points, and college degrees
Two types of positive reinforcers
1. Primary reinforcers: rewards that do not
require shaping or prior training to be effective.
Ex. Food, pleasurable sensations
• David Premark (1971): primary reinforcers can
be identified by looking as what people spend
most of their time doing.(riding a bike, sleeping,
playing video games). Premark Principle: high
probability responses can be used to reinforce
lower probability responses. Using ice cream
(high probability) to get a kid to eat vegetables
(low probablility response)
• 2. Secondary reinforcers- things that
become reinforcing through experience
and learning.
• Ex: dolphin trainers blow a whistle as they
reward the dolphins with fish. Eventually,
the dolphins associate the whistle with
food, and the whistle is reinforcing in and
of itself.