learning(lecture)

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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