learning(lecture)
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8/3/2019 Learning(lecture)
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Learning
Definition:
The ability to acquire knowledge and new experience which cause relative permanentchanges in the behavior
Learning helps us in mastering new skills and academic subjects
Learning is also involved in emotional development, social interaction and
personality development.
Approaches to learning:
1) Behavioral approach: in this type of learning we learn new behaviorthrough the principle of association of the learned behavior with external
factor (i.e. associative learning). The associative learning involve twotypes of learning; classical conditioning and operant conditioning
2) Cognitive approach: which involve the acquisition of knowledge orunderstanding of certain events. It involves changes that occur within
one's cognition. Insight learning is one type of such approach.
Classical conditioning: is a type of learning in which an originally naturalstimulus comes to evoke a new response after having been paired( associated) with
another stimulus that reflexively evoke the same response
Pavlov experiment: If we present food to a dog, the salivation response follows. In
this case food is considered as unconditioned stimulus (UCS) and salivation is an
unconditioned response (UCR) i.e. both do not depend on previous learning.
If we present another natural stimulus e.g. red light, it will not give a response to
such dog.
If the two stimuli; light (natural stimulus) and food (UCS); are presented together for
several times, the light stimulus alone will acquire the capacity to provoke a
salivation response in such dog. So the light will be considered as conditioned
stimulus (CS) and salivation it provoke will be a conditioned response (CR) i.e.learned through conditioning
Repetition of such procedure will result in permanent change in the behavior as a
result of such experience, so presentation of the CS alone will provoke CR i.e.
learning happened.
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Laws characterize classical conditioning:
1) Acquisition : It is an increased in the strength of the CR that occurs
after repeated pairing of the CS with the UCS. Thus the more
presentation of the light (CS) and the food (UCS) together, themore the dog will salivate (CR) in response to the light (CS) if it
presented alone.
2) High-order conditioning : establishment of a second stimulus-
response relation based on previously learned one e.g. presentation
of a tone sound prior of the presentation of the light, the sound will
be a new CS and provoke a new CR.
3) Extinction and spontaneous recovery : Extinction is the decrease ofthe strength of the CS-CR relation that occurs when the CS is
repeatedly presented without being paired with the UCS.
Spontaneous recovery is the return of the CR (salivation) after
extinction. After a period of rest the dog salivates again if being
presented with CS.
4) Generalization and discrimination : Generalization involves the
transformation of the CS-CR relation to another stimulus similar
to the original CS i.e. red light and pink light will both provoke
salivation. The more similar the new stimulus to the original CS the
greater will be the CR. Discrimination involve presentation of
different stimulus to the dog (e.g. blue, red ,orange, pink colors)
but pair the UCS (food) with only one of them, the one CS that the
dog will salivate to it (selective conditioning).
Whereas generalization is a reaction to similarities, discrimination
is a reaction to differences.
5) Predictability : those stimuli that are most effective as CS are those
that are reliably predict the UCS. The CS must be a reliablepredictor of the UCS i.e. there must be a higher probability that
the UCS will occur when the CS has been presented.
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Operant conditioning:It is the type of learning that depend on "the law of Effect" the described by (1898)
who stated that" responses are learned when they are followed by reward (is
reinforced). Alternatively, if a response is not followed by a reward or satisfaction (is
not reinforced) then the organism will tend not to make the response again.
Thorndike experiment: if we put a cat in a Skinner's box (a box with one door that
lead to a food plate and one lever to open the door) the cat engage in a trial and error
behavior and when one behavior if followed by reward (i.e. opening of the door and
receiving food) such behavior is likely to be repeated while other behaviors is not.
Laws characterize operant conditioning:
1) Reinforcement : the establishment of a connection between a
stimulus and a response. Reinforcers are stimuli that increase the
rate of the responses that follow them. Reinforcers can be positiveor negative. Positive Reinforcers are stimuli that increase the rate
of the responses, when theses stimuli are presented after a response
is made they are able to stimulate the repetition of such response. It
is a reward like food, money, praise and attention.
Negative Reinforcers is the avoidance of unpleasant events to
reward a desired behavior and stimulate the repetition of such
behavior. It is annoying stimuli when removed after a response is
made, the rate of such response will increase.
2) Schedules of reinforcement :
a) Continuous reinforcement: is presented every response and the
least resistant to extinction.
b) Fixed reinforcement: is presented after a set number of
responses (fixed ratio) or after a fixed time limit during the
responses (fixed-interval).
c) Variable reinforcement: occurs after a random and
unpredictable number of responses and is very resistant to
extinction. The most rapid acquisition of behavior is associated
with variable reinforcement (variable ratio or variable interval)
3) Punishment : is a noxious stimulus that presented after a behavior
to prevent its recurrence in the future. Punishment can effectively
eliminate an undesired behavior if the alternative responses are
rewarded.
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4) Acquisition, Extinction and spontaneous recovery :
Acquisition is produced by reinforcing a desired response so its
rate will increase.
Extinction is the phenomena of decreasing a response by
withholding reinforcement.
Spontaneous recovery is the return of the previously learned afterreinstallation of reinforcement.
5) Shaping : production of a new behavior by reinforcement of natural
responses which approximate to the desired one. Thus shaping
involves rewarding closer and closer approximations at the desired
behaviors until the correct behavior is achieved. So we shape a
desired responses by reinforcing successive approximations to that
response e.g. to train the cat to press the lever we can give the
animal food reinforce each time it approaches the area of the lever,acquiring a closer move to the lever, or touching the lever.
6) Chaining : teaching a complex behavior by breaking them into
simple components. The first action in the sequence is reinforced;
once acquired, reinforcement is given only following both the first
and second components and so on until the complete sequences is
established.
Classical conditioning Operant conditioning
Stimulus determines the
response
Behavior determines the
response
Animal is passive Animal is active
Responses are involuntary
e.g. salivation
Responses are voluntary e.g.
lever pressing
Involve autonomic nervous
system
Involve cranio-spinal nervous
system
Cognitive Concepts of learning:1) Learning set: previously learned experience can affect present and
future learning, so it can make them easier. E.g. we can not teach
student all the answers of the entire questions but can teach those
strategies to deal with similar tasks in the future.
2) Latent learning: the acquisition of information that may not be
demonstrated in performance until later.
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3) Social learning (modeling): when learning tasks takes place
through the observation and the imitation of a model. In such case
the behavior of the observer is affected by the behavior of the
model. In such observational learning a reinforced behavior of
valued models are more likely to be imitated than the punished
behavior of less valued model.
Application of learning in medicine:1)Systemic desensitization: was first described by Wolpe (1958) for the treatment of
phobia. The individual is exposed to the frightening stimuli in increasing doses in
conjunction with relaxation experience and as relaxation is incompatible with fear,
the relaxed patient is less likely to be anxious when the frightening stimulus is
presented. The following stages are involved:
1. Patient prepare a hierarchy of fear inducing objects or situations. 2.
Patient is taught a muscular relaxation technique 3.While
relaxed patient is asked to visualize the first object in the hierarchy. That procedureis repeated several times until the object no longer induce fear.
4. Using the same procedure as step-by-step the patient move up in the hierarchy
2) Aversion therapy: pairing of unwanted behavior with a painful
(aversive) stimulus e.g. pairing of the consumption of alcohol with
nauseating effect of disufiram reduce the desire for alcohol.
3) Flooding: involve a maximum exposure to the anxiety provoking
object or situation.
4) Token economy: individuals are paid for desired behavior by token
reinforcers which later translated into objects such as candy or dessert.
5) Biofeedback: learning control over physiological activity. It
considered as a practice for operant conditioning when reward (either
positive or negative) is used to train the individual about the voluntary
control of involuntary events. Biofeedback have been used to produce
voluntary control over autonomic nervous system to treat hypertension,
peptic ulcer and asthma as well as peripheral temperature regulation in
treatment of migraine headache. Biofeedback involve relaxation of skeletal
muscles has been used in treatment of tension headache and generalized
anxiety disorders.
6) Other clinical uses of behavioral techniques include the bell andpad method for treatment of nocturnal enuresis and thought stoppage for
treatment of obsessive compulsive disorder.
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