10. Law of effect
Rewarded behavior is likely to
recur!!!
Logically, behaviors followed by
unfavorable consequences become
less likely.
Edward L. Thorndike
This was Skinner’s starting point.
11. 1. Shaping
An operant conditioning procedure in
which reinforcers guide behavior toward
closer and closer approximations of the
desired behavior.
Training a rat to press a bar.
12. 2. EXTINCTION
Extinction consists simply of withholding the
reinforcer when the appropriate response occurs.
Withholding the reinforcer means extinction of
previously established relationship
Suppose in Skinner box the rat presses the bar but
does not get pellet of food
If this is repeatedly done , the bar pressing behavior
of rat will be extinguished
13. 3. Spontaneous Recovery
It refers to the fact that if an organism is
removed from the situation for a while and
again presented with S1,his performance will
be better than would be predicted from his
performance at the end of preceding
extinction.
14. Reinforcers
Any event or stimulus, that when following a
response, increases the probability that the
response will occur again.
Can be material, such as a cookie, money, drugs.
Can be immaterial, such as attention, praise, good
grades, or the absence of something.
Can be abstract, such as a sense of accomplishment or
satisfaction, being ―right.‖
Note: What is reinforcing for one may NOT be
reinforcing for another.
15. Two types of
reinforcers
A. Positive reinforcer
The reinforcement of a response by the addition or
experiencing of a pleasurable stimulus. (adding
something to the equation)
Examples:
Training a dog using doggie treats
Paycheck at the end of the month.
Giving a child what he wants when he finishes his
home work.
16. Reinforcement
(This is actually positive reinforcement)
Response- event/stimulus same response again
(behavior)
Cleans
His room gets a cookie - likely to do it again to
get another cookie.
Study hard
For a test. - gets an A - will study hard next time
to get an A again
17. Negative reinforcer
The reinforcement of a response by the
removal, escape from, or avoidance of an
unpleasant stimulus. (i.e. subtracting
something from the equation)
Response unpleasant thing same response
(behavior) removed, escaped, again
or avoided
Take Paracetamol headache goes away take
paracetamol
again
18. Negative Reinforcer
Examples:
Put on seat belt to stop the warning beeper.
Drink alcohol to take the stress/anxiety away.
After drinking coffee, grogginess goes away.
Parent gives a child what they wants to stop the
whining. (unpleasant situation is escaped.)
19. Primary and Conditioned
Reinforcers
1. Primary Reinforcer: Innately reinforcing
stimulus like food or drink. (Usually satisfies a
biological need.)
2. Conditioned Reinforcer: Is a learned
reinforcer. It gets its reinforcing power
through its association with primary
reinforcer. Sometimes called secondary
reinforcers. (praise, paycheck, good grades,
attention, etc)
20. 15
1. Immediate Reinforcer: A reinforcer that
occurs closely to a behavior in time. Rat gets a
food pellet for a bar press.
2. Delayed Reinforcer: A reinforcer that is
delayed in time for a certain behavior. A
paycheck that comes at the end of a week.
Immediate & Delayed Reinforcers
We may be more inclined to engage in small immediate
reinforcers (watching TV) than large delayed reinforcers
(Getting A in a course) which requires consistent study.
21. Schedule for Reinforcement
Continuous Partial
1. Schedule the response
produces reinforcement
every time it occur
1. Schedule some but not all
responses are reinforced
Ex : We can praise a child each
time he adds two numbers
Ex : We can praise a child for
correct addition only the time
22. 16
Reinforcement Schedules
1. Continuous Reinforcement: the
reinforcement of each and every correct
response.
2. Partial Reinforcement Effect: the
tendency for a response that is reinforced
after some, but not all, correct responses to
be very resistant to extinction.
23. 17
Ratio Schedules
1. Fixed-ratio schedule: Reinforces a
response only after a specified number of
responses e.g., like piecework pay.
Child gets a reward for every 10 stars he earns.
2. Variable-ratio schedule: Reinforces a
response after an unpredictable number of
responses.
Slot machines
Fishing
(Hard to extinguish because of unpredictability.)
24. 18
Interval Schedules
1. Fixed-interval schedule:
Reinforces a response only after a specified
time has elapsed.
Paycheck comes every two weeks.
Mail delivery once a day.
2. Variable-interval schedule:
Reinforces a response at unpredictable
time intervals produces slow steady
responding.
Pop quizes.
Unannounced inspections.
25. 23
Punishment
An aversive event that decreases the behavior
that it follows.
Response aversive event response doesn’t
happen again
Jimmy shaves Jimmy never
the cat for fun spanking shaves the cat
again
(This is an example of positive punishment.)
26. Positive Punishment: an aversive stimulus
that decreases the behavior that it follows.
“Punishment by application.”
A spanking.
A parking ticket / prison sentence
Negative Punishment:withdrawing a desirable
stimulus that decreases the behavior that it follows.
“Punishment by removal.”
Response (behavior) don’t do that
response again
remove pleasant
or desirable
stimulus
Time outs from privileges.
Revoked drivers licenses.
27. 25
Punishment
1. It can cause the organism to avoid the punisher
instead of the behavior.
2. Punishment can create fear & anxiety, which does
not promote learning.
3. It conveys no information to the organism.
4. Unwanted behaviors may reappear in its absence or
another unwanted behavior replaces it.
5. In people, it may encourage lying to avoid the
punishment.
6. It may result in aggression towards the agent.
7. For people, hitting provides a successful model for
aggression.
28. If you must punishment…
It should immediately follow the behavior
it is meant to punish.
It should be consistent.
Punishment of the wrong behavior should
be paired, whenever possible with
reinforcement of the right behavior.
29. Applying Operant conditioning…
Behavior modification – the use of operant
conditioning techniques to bring about desired
changes in behavior. Used in schools, psychiatric
wards, prisons…even animal training.
Select target
Choose reinforcer
Reinforce right behavior; do not reinforce
inappropriate behavior
What is a token economy?
a type of behavior modification in which desired
behavior is rewarded with -tokens
31. 29
Applying Operant Conditioning…
At work, reinforcers affect productivity. Many
companies now enable employees to share profits
and participate in company ownership.