Download Chapter 5 Learning

Chapter 5 Learning
Yonghui Wang
School of Psychology
Shaanxi Normal University
2010.10.12
Chapter 5 Learning
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Learning is a fundamental topic for
psychologists and plays a central role in almost
every specialty area of psychology.
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Chapter 5 Learning
Our goals:
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Identify four elements of Classical conditioning
Explain these processes: extinction, spontaneous recovery,
stimulus generalization, discrimination.
Distinguish between classical and operant conditioning.
Explain the principle of reinforcement. Define primary
reinforcer and secondary reinforcer.
Distinguish four schedules of reinforcement, and give
examples of each.
Distinguish positive reinforcement, negative reinforcement,
punishment.
Distinguish between cognitive learning and traditional
theories of conditioning.
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Chapter 5 Outline
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What sort of learning does classical conditioning
explain?
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How do we learn new behaviors by operant
conditioning?
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How does cognitive psychology explain learning?
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What is learning?
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Learning: A lasting change in behavior or
mental processes that results from experience.
How do we know when a behavior has been
influenced by learning——or even is a result
of learning?
Part of the answer relates to the naturenurture question.
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The acquisition of behaviors, experience is the
“nurture” part.
Inherited, genetic factors represent the “nature”
part.
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What is learning?
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Some forms of learning
 Simple
 Habituation（习惯化）
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Habituation is an extremely simple form of
learning, in which an animal or a baby,
after a period of exposure to a stimulus,
stops responding.
Habituation is important in filtering the large
amounts of information received from the
surrounding environment.
Mere exposure effect （单纯接触效应）
(i.e. the advertising of McDonald’s)
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What is learning?
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Some forms of learning
 Simple
 Classical conditioning（经典条件反射）
 Operant conditioning（操作条件反射）
 Cognitive learning（认知学习）
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Classical conditioning
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Classical conditioning（经典条件反射） is a basic
form of learning in which a stimulus that
produces an innate reflex becomes associated
with a previously neural stimulus, which then
acquires the power to elicit essentially the same
response.
Ivan Pavlov,
a Russian physiologist
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Pavlov's Conditioning Experiments
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Classical conditioning
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Some important terms
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Neutral stimulus (NS) （中性刺激）
 Any stimulus that produces no conditioned
response prior to learning. When it brought
into a conditioning experiment, the
researcher will call it a conditioned stimulus.
Unconditioned stimulus (UCS, or US) （非条件刺激）
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The stimulus that elicits an unconditioned
response (without having been learned).
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Classical conditioning
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Unconditioned response (UCR, or UR) （非条件反应）
The response elicited by an unconditioned
stimulus without prior learning (e.g., salivation
at the smell of food).
Conditioned stimulus (CS)（条件刺激）
 A once-neutral stimulus that has been paired
with an unconditioned stimulus to bring about
a response formerly caused only by the
unconditioned stimulus.
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Classical conditioning
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Conditioned response (CR)（条件反应）
 A response elicited by a previously
neutral stimulus that has become
associated with the unconditioned
stimulus ( e.g., salivation at the ringing of a
bell).
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Classical conditioning
Can you give some examples of
classical conditioning?
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Phases of Classical Conditioning
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Elements of Classical Conditioning
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Unconditioned stimulus
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Unconditioned response
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Response to unlearned stimulus
Conditioned stimulus
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Unlearned, inborn, innate
Stimulus that is learned
Conditioned response
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Response to learned stimulus
Can you figure out the relationship between
stimuli and responses?
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Components of Classical Conditioning
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Acquisition（习得）
 The initial learning stage in classical
conditioning, during which the conditioned
response comes to be elicited by the
conditioned stimulus.
Stimulus Generalization （泛化）
 The extension of a learned response to
stimuli that are similar to but different from
the conditioned stimulus.
 for example
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Components of Classical Conditioning
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Stimulus Discrimination （分化）
 A change in responses to one stimulus but
not to stimuli that are similar.
 for example
Extinction（消退）
 The weakening of a conditioned response
in the absence of an unconditioned
stimulus.
 for example
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Components of Classical Conditioning
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Has it vanished forever once a conditioned
response has been extinguished?
 Good news: not necessary.
Spontaneous Recovery（自发恢复）
 The reappearance of an extinguished
conditioned response after a time delay.
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Components of Classical Conditioning
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Spontaneous Recovery（自发恢复）
Extinction
Acquisition
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Spontaneous
recovery
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Applying Conditioning Principles
to Human Behavior
Can you recall some Applications
of classical conditioning?
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Challenging basic assumptions
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Recall the classical conditioning first
Cognitive psychology
 Learns actively develop an expectancy
about the relationship between the
unconditioned stimuli and conditioned
stimuli.
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Learning psychology (John Garcia)
 The experience of the rats
a)violated one of the basic rules—that an
unconditioned stimulus should immediately follow
a conditioned stimulus. The interval can as long as
eight hours.
b)The conditioning sometimes occurred after just
one exposure to water that was followed later on
by illness.
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Classical Conditioning Is Selective
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Research demonstrating that we develop
phobias about snakes and spiders, for
example, but almost never about flowers or
cooking utensils illustrates Seligman's
principles of preparedness and
contrapreparedness, respectively.
The ease with which we develop conditioned
food (or taste) aversions also illustrates
learning preparedness.
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Conditioned food aversions are exceptions to
the general rules about classical conditioning.
Animals can learn to avoid poisonous food
even if there is a lengthy interval between
eating the food and becoming ill. In many
cases, only one pairing of conditioned and
unconditioned stimuli is necessary for
learning to take place.
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Thorndike's law of effect
Look at this
experiment at first.
 Law of effect
（效果律）
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Skinner’s box
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Operant Conditioning
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Operant conditioning, or
instrumental conditioning is learning
in which a voluntary response is strengthened
or weakened, depending on its favorable or
unfavorable consequences.
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Components of Operant Conditioning
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Reinforcement and Reinforcer （强化和强化物）
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Punishment（惩罚）
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Positive reinforcement and positive reinforcers
Negative reinforcement and negative reinforcers
The punishment dilemma（惩罚的两难选择）
Shaping（塑造）
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The process of teaching a complex behavior by
rewarding closer and closer approximations of the
desired behavior.
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Reinforcement and Reinforcer
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Reinforcement
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The process by which a stimulus increases
the probability that a preceding behavior
will be repeated.
Reinforcer
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Any stimulus that increases the probability
that a preceding behavior will occur again.
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Reinforcement and Reinforcer
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Positive reinforcer
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A stimulus added to the environment that
brings about an increase in a preceding
response.
Negative reinforcer
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An unpleasant stimulus whose removal
leads to an increase in the probability that
a preceding response will occur again in the
future.
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Reinforcement and Reinforcer
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Primary reinforcer
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A reinforcer that can satisfy a basic
biological need, most likely food or water.
Secondary reinforcers
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The reinforcers that do not satisfy a basic
biological need but acquire their rewarding
power by association with another
established reinforcer.
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Punishment
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The pros and cons of punishment
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Advantage
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Should be swift, sufficient
Protection
Disadvantage
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Not as effective as reinforcement
Not usually permanent
Not convey any information of alternative behavior
May result in anxiety of aggressive behavior
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Punishment
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Question
When should we use punishment
and when the reinforcer?
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Schedules of Reinforcement
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Continuous reinforcement（持续强化）
Partial reinforcement（部分强化）
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Fixed-ratio schedule（比率固定）
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Variable-ratio schedule（比率不定）
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Fixed-interval schedule（间隔固定）
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Number of responses
Variable-interval schedule （间隔不定）
Amount of time
Can you give examples of each schedule?
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Schedules of Reinforcement
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What are the
characters of
each schedule?
Which one is
better?
Can you design a
plan for more
efficiency?
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The Application of Operant Conditioning
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Computer-Assisted Instruction (CAI)（计算机辅助教
学）
 Students learn at their own rate, using computers
that are programmed to deliver individual
instruction.
Behavior Modification（行为矫正）
 A formalized technique for promoting the
frequency of desirable behaviors and decreasing
the incidence of unwanted ones.
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Comparing Classical And Operant
Conditioning
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Similarities
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involve associations between stimuli and
responses
subject to extinction and spontaneous recovery as
well as generalization and discrimination.
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Comparing Classical And Operant
Conditioning
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Differences
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The stimuli is before response in Classical
Conditioning, while stimuli is after response in
Operant Conditioning.
The stimuli (food) in Classical Conditioning is
using as UCS, while stimuli is after response serve
as a reinforce in Operant Conditioning.
The response is more ”voluntary” in Operant
Conditioning.
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Cognitive-Social Approaches to Learning
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Latent Learning and Cognitive Maps
Learning takes place before the subject realizes it
 Cognitive map is latent learning stored as a
mental image
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Insight and Learning Sets
Learning seems to occur in a “flash” with insight
 Learning sets refer to increasing effectiveness at
problem solving through experience
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Cognitive-Social Approaches to Learning
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Learning by Observing
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Observational or vicarious learning（观察学习或替
代学习）
Social learning theorists
Vicarious reinforcement or vicarious punishment
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Learning by Observing
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Learning by Observing
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Results
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Learning by Observing
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Social learning theory argues that we learn not just
from firsthand experience, but also from watching
others or by hearing about something. Albert
Bandura contends that observational (or vicarious)
learning accounts for many aspects of human
learning.
The extent to which we display behaviors that have
been learned through observation can be affected by
vicarious reinforcement and vicarious punishment.
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