1. Classical Conditioning Operant Conditioning Learning by Observation
Modules Learning
Classical Conditioning
Operant Conditioning
Learning by Observation

2. Review
Learning is a relatively permanent change in behavior that occurs as the result of experience.
Associative Learning: learning that two events occur together
Conditioning: the process of learning associations
Classical conditioning
Unconditioned stimulus (food) is paired with a neutral stimulus (bell)  conditioned stimulus (bell)
Unconditioned response (saliva) becomes conditioned response (saliva)
Acquisition, extinction, spontaneous recovery, generalization, discrimination

3. Classical Conditioning: Important Limitation
Focuses on naturally occurring responses
Any naturally occurring behavior (or response) can be conditioned to neutral stimulus
WHAT ABOUT THOSE BEHAVIORS THAT ORGANISMS DO NOT NATURALLY PERFORM?

4. Module 19 - Operant Conditioning
Learning that behaviors are associated with their consequences

5. The Principle of Operant Conditioning
Learning in which behavior is strengthened if followed by a reinforcer and weakened if followed by a punisher
What is a reinforcer?
What is a punisher?

6. The Basic Principle of Operant Conditioning: Thorndike's Law of Effect
Good Outcome
Strengthens
Behavior
Bad Outcome
Weakens

7. Differences between classical and operant conditioning
Classical Conditioning
Operant Conditioning
Associative learning
Learning that CS signals pending US
Learning that a behavior and its consequences go together
Behavior
Respondent behavior: occurs automatically
Operant behavior: behavior operates on the environment and produces consequences
Consequences of conditioning
Behavior is repeated IF CS is given, in anticipation of the US
Frequency of a behavior is changed in anticipation of its consequence

8. Skinner’s (late 20th century) behavioral technology
Operant chamber / Skinner box: A highly controlled environment where reinforcers are carefully administered.

9. Teaching complex behaviors: Shaping
A procedure in which reinforcers guide behavior towards gradually closer approximations of the desired behavior.
Build on existing behaviors that occur by chance
Make rewards contingent on closer approximations

10. How to strengthen behavior: Reinforcement
Provide a reward = positive stimulus
If presented AFTER a response, it strengthens the response
E.g., food, pleasurable sensation, …
Take away something that is undesirable or unpleasant = reduce negative stimulus
If removed AFTER a response, it strengthens the response
E.g., A whining child being quiet, seat belt warning sound not beeping, alarm clock going quiet, reduction of feeling of guilt after you call your grandmother

11. Types of Reinforcers Primary Reinforcer
innately satisfies a biological need
Food, security, positive feelings
Conditioned (secondary) Reinforcer
stimulus that is reinforcing because it is associated with a primary reinforcer
Money, good grades, words of praise, pleasant tone of voice

12. When should we reinforce
When should we reinforce? How soon after the behavior should we reinforce?
Immediate reinforcers are the only ones that work with most animals.
Immediate reinforcers are more powerful than delayed reinforcers.
Ability to sustain motivation for delayed reinforcers requires cognitive engagement.
Humans can respond to delayed reinforcers- --like salary at the end of the month, good grades at the end of the semester.
Can postpone immediate rewards for bigger rewards in the long term---
Real life does not provide continuous reinforcement. We are occasionally rewarded.
Responses are sometimes rewarded sometimes not.

13. How often should we reinforce? All the time or some of the time?
Continuous Reinforcement
reinforcing the desired response each time it occurs
learning occurs rapidly
Partial (Intermittent) Reinforcement
reinforcing a response only part of the time
results in slower acquisition but greater resistance to extinction
Timing:
Intial learning is slower in intermittent – so prefer continuous for learning. Then use intermittent for persistence

14. Reinforcing some of the time
Number of times the behavior is performed
Some duration of time after the behavior is performed
Fixed Ratio
Variable Ratio
Fixed Interval
Variable Interval

15. Schedules of Intermittent Reinforcement based on frequency of behavior
Fixed Ratio Schedule:
faster you respond the more rewards you get (e.g. piecework pay, frequent flyer programs)
very high rate of responding because resting reduces rewards
Variable Ratio:
very hard to extinguish because of unpredictability
very high rate of responding because resting reduces rewards (e.g. gambling, fishing)
Commisions of salespeople
Frequent flyer – get rewarded after flying X amount of miles.

16. Schedules of Intermittent Reinforcement based on time interval
Fixed Interval:
response occurs more frequently as the anticipated time for reward draws near (e.g. Monthly payments, checking to see if the cake is baked, studying hardest before the mid term)
Variable Interval:
produces slow steady responding (e.g. pop quiz, checking for from a loved one)

17. Schedules of Reinforcement
Variable Interval
Number of
responses
1000
750
500
250 10 20 30 40 50 60 70
Time (minutes)
Fixed Ratio
Variable Ratio
Fixed Interval
Steady responding
Rapid responding
near time for
reinforcement 80