PSY-150/Withrow
September
29, 2003
Chapter
Five: Learning
Learning is
the process by which experience or practice results in a relatively permanent
change in behavior or potential behavior.
Classical
or Pavlovian conditioning is the type of learning in which a response naturally
elicited by one stimulus comes to be elicited by a different, formally neutral
stimulus. Based on Pavlov’s experiments with dogs. He would ring a bell before
feeding the dogs. After a while, the dogs would begin to salivate as soon as
they heard the bell because to the dogs the bell signaled the appearance of
food. The dogs began to salivate on cue (bell) even when there was no food. The
dogs were therefore conditioned to salivate in response to new stimulus (the
bell) that would normally not prompt salivation.
Elements of
classical conditioning are unconditioned stimulus, unconditioned response,
condition stimulus, and conditioned response. Unconditioned stimulus (US) is a
stimulus that automatically elicits a certain reflex action. In Pavlov’s
studies, the food in the dog’s mouth was the unconditioned stimulus. An
unconditioned response (UR) is a response that takes place in an organism
whenever an unconditioned stimulus occurs. In Pavlov’s studies, the dog’s
salivation is the unconditioned response. A conditioned stimulus is an
originally neutral stimulus that is paired with an unconditioned stimulus and
eventually produces the desired response in an organism when presented alone.
Pavlov’s repeated use of the bell trigged the dog’s salivation. Therefore the
bell was the conditioned stimulus. A conditioned response is the response an
organism produces when a conditioned stimulus is present, a learned reaction.
The pairing
of the conditioned stimulus and the unconditioned stimulus on only a portion of
the learning trials is called intermittent pairing. It is important that the
pairings be neither too far apart or too close together.
Other
examples of classical conditioning: eating when not hungry but doing so because
we know it’s lunch time or a specific smell triggering a bad memory.
Desensitization
therapy is a conditioning technique designed to gradually reduce anxiety about
a particular object or situation and starts with teaching a system of deep
muscle relaxation. With desensitization, a fear-arousing thought is repeatedly
paired with a muscular state that produces calmness until eventually the
formally fearful thought no longer trigger anxiety.
Operant or
instrumental conditioning is learning to make or withhold a certain response
because of its rewards or punishment. Emitted behavior is one essential element
in operant conditioning. Behavior designed to operate on the environment in a
way that will gain something desired or avoid something unpleasant are operant
behaviors. There are two types of consequences in operant behavior: the
reinforcer and the punisher. The reinforcer occurs when a consequence increases
the likelihood of operant behavior being emitted and the punisher occurs when a
consequence decreases the likelihood of operant behavior. Edward Lee
Thorndike’s Law of Effect is a theory that behavior consistently rewarded will
be “stamped in” as learned behavior and behavior that brings about discomfort
will be “stamped out.” Because behaviors involved in operant conditioning are
voluntary, it is not easy to establish an operantly conditioned response. The
desired behavior must first be performed spontaneously in order for it to be
rewarded and strengthened. One way to speed up the process is to increase the
motivation. Examples of operantly learned behavior would be studying to gain a
teacher’s approval. Another way to speed up the process is to reinforce
successive approximations of the desired behavior, referred to as shaping.
Food, praise, or money that add something rewarding to a situation would be
considered a positive reinforcer, encouraging the ongoing behavior. Stopping an
aversive noise or taking away something unpleasant would be considered a negative
reinforcer, also encouraging the ongoing behavior. Both positive and negative
reinforcements result in the learning of new behaviors or the strengthening of
existing behaviors.
Punishment
is any event whose presence decreases the likelihood that the ongoing behavior
will recur. Punishment adds something unpleasant to he environment therefore
weakening the behavior that caused it. Drawbacks to punishment include stirring
up negative feelings, models of aggressive behavior, and suppression of
undesirable responses. When a threat of punishment induces a change to more
desirable behavior it is called avoidance training. Learned helplessness is a
“giving up” response that causes resignation in the face of unpleasant outcomes
even when the outcomes can be avoided.
Similarities
between classical and operant conditioning: 1) both involved learned
associations, 2) extinction and spontaneous recovery, 3) generalization, 4)
discrimination, 5) involve stimulus control.
Contingency
is a relationship in which one event depends on another existing between two
stimuli or between a stimulus and a response. In classical conditioning, the
contingency is between the conditioned stimulus and the unconditioned stimulus.
In operant conditioning, the contingencies exist between the responses and the
consequences.
In operant
conditioning:
The rule
for determining when and how often the reinforcers will be delivered is the
schedule or reinforcement. Partial reinforcements are rewards given for some
correct responses but not every one generating behavior that persists longer
than behavior that is generated by continuous reinforcement. In a
fixed-interval schedule, reinforcement comes on the first correct response
after a fixed length of time has passed since the last reinforcement resulting
in a slow, steady pattern of responding as the learner keeps testing for the
next payoff. In a fixed-ratio schedule, the correct response is reinforced
after a fixed number of correct responses, resulting in a high rate of response
because faster responses yield quicker payoffs. In the variable-ratio schedule,
a varying number of correct responses must occur before reinforcement is
presented resulting in a high response rate since the person keeps harboring
the idea that he next response will bring a reward.
Extinction,
a factor shared by both classical and operant conditioning, is a decrease in
the strength or stopping of a learned response. After extinction and a period
of rest, a conditioned response may suddenly reappear, reminded of an old association.
This is called spontaneous recovery. In classical conditioning, extinction is
caused by the failure to continue pairing the conditioned stimulus with the
unconditioned stimulus. In operant conditioning, extinction happens as a result
of withholding reinforcement.
The control
of conditioned responses by stimuli in the environment is stimulus control and
occurs in both classical and operant conditioning. The process by which a
learned response to a specific stimulus comes to be associated with different
but similar stimuli is known as stimulus generalization. Stimulus
discrimination is a process through which learners can be trained not to
generalize but rather to make a conditioned response only to a single specific
stimulus. As a result, behavior becomes more finely tuned to the demands of the
environment. Higher-order conditioning is based on previous learning where the
conditioned stimulus serves as the unconditioned stimulus for further training.
Reinforcers
that are rewarding in itself, such as food, water, and sex, and in which no
prior learning is need to make them reinforcing are primary reinforcers.
Secondary reinforcers need prior learning and are reinforcers whose value is
acquired through association with other primary or secondary reinforcers.
The main
difference between classical and operant conditioning is that in classical
conditioning, the learner is passive and the behavior involved is usually
involuntary. In operant conditioning, the learner is active and the behavior
involved is usually voluntary.
Cognitive
learning depends on mental processes that are not directly observable. Latent
learning is learning that is not immediately reflected in a behavior change.
Rewards and punishment are necessary for latent learning to take place. A
cognitive map is a learned mental image of a spatial environment that may be
called upon to solve problems when the stimuli in the environment change, a
storing of visual perceptions. Insight is learning that occurs as a result of
understanding all the elements of a problem. The ability to become increasingly
more effective in solving problems as more problems are solved is a learning
set. The learning set provides a key to solving a problem even when its demands
are slightly different from those problems solved in the past.
Observational
or vicarious learning is learning by observing other people’s behavior. Social
learning theorists are psychologists whose view of learning emphasizes the
ability to learn by observing a model or receiving instructions without first
hand experience. According to social learning theory, humans use their powers
of observation and thought to interpret their own experiences and those of
others when deciding how to act. Vicarious reinforcement or vicarious
punishment affects the willingness of others to perform the behaviors they
learned by observing so that when a consequence for a behavior isn’t
experienced first hand but only occurs to other people.
