learning theory

Learning Theoryد.وليد عزيز العميدي
A. Learning is the acquisition of new behavior patterns.
B. Methods of learning include simple forms, such as habituation and sensitization, and more complex types, including classical conditioning and operant conditioning.
C. Learning methods are the basis of behavioral treatment techniques, such as systematic desensitization, aversive conditioning, flooding, biofeedback, token economy, and cognitive therapy.

HABITUATION AND SENSITIZATION
A. In habituation (also called desensitization), repeated stimulation results in a decreased response (e.g., a child who receives weekly allergy injections cries less and less with each injection(
B. In sensitization, repeated stimulation results in an increased response (e.g., a child who is afraid of spiders feels more anxiety each time he encounters a spider.)

CLASSICAL CONDITIONING
A. Principles.
In classical conditioning, a natural or reflexive response (behavior) is elicited by a learned stimulus (a cue from an internal or external event). This type of learning is called associative learning.
1.The hippocampus is particularly important in associative learning.
2-The cerebellum participates in classical conditioning, specifically in associations involving motor skills.
B. Elements of classical conditioning
1-An unconditioned stimulus is something that automatically, without having to be learned, produces a response (e.g., the odor of food(
2. An unconditioned response is a natural, reflexive behavior that does not have to be learned (e.g., salivation in response to the odor of food (
3-A conditioned stimulus is something that produces a response following learning (e.g., the sound of the lunch bell (
4-A conditioned response is a behavior that is learned by an association made between a conditioned stimulus and an unconditioned stimulus (e.g.,salivation in response to the lunch bell. )
C. Response acquisition, extinction, and stimulus generalization
1. In acquisition, the conditioned response (e.g., salivation in response to the lunch bell) is learned.
2. In extinction, the conditioned response decreases if the conditioned stimulus (e.g., the sound of the lunch bell) is never again paired with the unconditioned stimulus (e.g., the odor of food).
3. In stimulus generalization, a new stimulus (e.g., a church bell) that resembles a conditioned stimulus (e.g., the lunch bell) causes a conditioned response (e.g., salivation).

D. Aversive conditioning.
An unwanted behavior (e.g., setting fires) is paired with a painful or aversive stimulus (e.g., a painful electric shock). An association is created between the unwanted behavior (fire-setting) and the aversive stimulus (pain) and the fire-setting ceases.
Learned helplessness
1. An animal receives a series of painful electric shocks from which it is unable to escape.
2. By classical conditioning, the animal learns that there is an association between an aversive stimulus (e.g., painful electric shock) and the inability to escape.
3. Subsequently, the animal makes no attempt to escape when shocked or when faced with any new aversive stimulus; instead, the animal becomes hopeless and apathetic.
4. Learned helplessness in animals may be a model system for depression (often characterized by hopelessness and apathy) in humans.
5. Antidepressant treatment increases escape attempts in animal models.
F. Imprinting
is the tendency of organisms to make an association with and then follow the first thing they see after birth or hatching (in birds).
OPERANT CONDITIONING
A. Principles
1. Behavior is determined by its consequences for the individual. The consequence (re-inforcement or punishment) occurs immediately following a behavior.
2. In operant conditioning, a behavior that is not part of the individual s natural repertoire can be learned through reinforcement or punishment.
B. Features
1. The likelihood that a behavior will occur is increased by positive or negative reinforcement and decreased by punishment or extinction (Table 7-1).

table 7–1Features of Operant Conditioning
Example: A mother would like her 8-year-old son to stop hitting his 6-year-old brother. She can achieve this goal by using one of the following features of operant conditioning.
Feature Effect on Behavior Example Comments
Positivereinforcement Behavior is increased by reward. Child increases his kind behavior toward his younger brother to get praise from his mother. Reward or (praise) increases desired
behavior (kindness toward brother).
A reward can be praise or attention as well as atangible reward like money.
Negative
reinforcement Behavior is increased by avoidance or
escape Child increases his kind behavior toward his younger brother to avoid being scolded. Active avoidance of an aversive stimulus (being scolded) increases desired behavior (kindness toward brother).
Punishment Behavior is decreased by
suppression.







Child decreases his hitting behavior after his mother scolds him. Delivery of an aversive stimulus (scolding) decreases unwanted behavior (hitting brother)
rapidly but not permanently.
Extinction Behavior is eliminated
by non
reinforcement. Child stops his hitting behavior
when the behavior
is ignored. Extinction is more effective than punishment for
long-term reduction in unwanted behavior.
There may be an initial increase in hitting behavior
before it disappears.
a. Types of reinforcement include:
1. Positive reinforcement (reward) is the introduction of a positive stimulus that results in an increase in the rate of behavior.
2. Negative reinforcement (escape) is the removal of an aversive stimulus that also results in an increase in the rate of behavior.
b. Punishment is the introduction of an aversive stimulus aimed at reducing the rate of an unwanted behavior.

2. Extinction in operant conditioning is the gradual disappearance of a learned behavior when reinforcement (reward) is withheld.
a. The pattern, or schedule, of reinforcement affects how quickly a behavior is learned and how quickly a behavior becomes extinguished when it is
not rewarded (Table 7-2).
table 7–2 Schedules of Reinforcement
Schedule Reinforcement Example Effect on Behavior
Continuous Presented after
every response A teenager receives a candy bar each
time she puts a dollar into a vending
machine. One time she puts a dollar
in and nothing comes out. She never
buys candy from the machine again Behavior (putting in a dollar to receive
candy) is rapidly learned but disappears rapidly (has little resistance to extinction)when not reinforced (no candy comes out).
Fixed ratio Presented after a
designated number
of responses A man is paid $10 for every five hats
he makes. He makes as many hats
as he can during his shift. Fast response rate (many hats are made
quickly)
Fixed interval Presented after a
designated amount
of time A student has an anatomy quiz every
Friday. He studies for 10 minutes on
Wednesday nights, and for 2 hours on
Thursday nights. The response rate (studying) increases
toward the end of each interval (1week(When graphed, the response rate forms a
scalloped curve.
Variable ratio Presented after a
random and
unpredictable
number of
responses After a slot machine pays off $5 for
a single quarter, a woman plays
$50 in quarters despite the fact
that she receives no further payoffs. The behavior (playing the slot machine) continues (is highly resistant to extinction) despite the fact that it is only reinforced
)winning money) after a large but variable number of responses.
Variable
interval Presented after a
random and
unpredictable
amount of time After 5 minutes of fishing in a lake a
man catches a large fish. He then
spends 4 hours waiting for
another bite. The behavior (fishing) continues (is highly resistant to extinction) despite the fact that it is only reinforced (a fish is caught(after varying time intervals.
b. Resistance to extinction is the force that prevents the behavior from disappearing when a reward is withheld.

C. Shaping and modeling
1-. Shaping involves rewarding closer and closer approximations of the wanted behavior until the correct behavior is achieved (e.g., a child learning to write is praised when she makes a letter, even though it is not formed perfectly )
2. Modeling is a type of observational learning (e.g., an individual behaves in a manner similar to that of someone she admires).