Learning

1. Learning Psychology: A Concise Introduction2nd Edition Richard Griggs Chapter 4 Prepared byJ. W. Taylor V

2. Different Perspectives • Behavioral psychologists have focused on the learning of associations through classical conditioning and operant conditioning • Cognitive psychologists studying learning are interested in the more complex type of earning involved in human memory

3. The Journey… • Learning Through Classical Conditioning • Learning Through Operant Conditioning • Biological and Cognitive Aspects of Learning

4. Learning Through Classical Conditioning The Elements and Procedures of Classical Conditioning General Learning Processes in Classical Conditioning

5. Classical Conditioning • The process of learning in which one stimulus signals the arrival of another stimulus • Sometimes called “Pavlovian” conditioning because Ivan Pavlov was the first researcher to systematically study this type of learning

6. Pavlov • A Russian physiologist studying digestive processes in dogs • The dogs were strapped into harnesses and had tubes inserted into their cheeks to measure the amount of salivation, the initial step in the digestive process • With time, he noticed that the dogs started to salivate before the meat powder was even put in their mouths, and wanted to know why this was happening

7. Elements and Procedures of Classical Conditioning Unconditioned Stimulus(UCS) Unconditioned Response(UCR) Associated Similar Conditioned Stimulus (CS) Conditioned Response (CR)

8. UCS and UCR • Dogs salivate when meat powder is put in their mouths – this is a reflex, a response that occur automatically in the presence of a certain stimulus (i.e., meat powder) • An unconditioned stimulus (UCS)is the stimulus that elicits the reflexive response (here, the UCS is the meat powder) • An unconditioned response (UCR)is the response automatically elicited by the UCS (here, the UCR is salivating in response to the meat powder)

9. CS and CR • A neutral stimulus is a stimulus that does not naturally elicit the to-be-conditioned response (e.g., auditory tones) • To achieve conditioning, the neutral stimulus (a tone) is presented just before (ideally one-half to one full second before) the UCS (meat powder) for several trials • Once the conditioning occurs (that is, the dog starts to salivate to the sound of the tone before the food is put in its mouth), the neutral stimulus is called the conditioned stimulus (CS) • The learned response to the conditioned stimulus is called the conditioned response (CR)

10. Delayed and Trace Conditioning • In delayed conditioning, the offset of the CS is delayed until after the UCS is presented so that the two stimuli occur at the same time • The tone would be turned on and continue to sound until the meat powder was placed in the dog’s mouth • In trace conditioning, there is a period of time between the offset of the CS and the onset of the UCS when neither stimulus is present • It is called “trace” conditioning because there must be a memory trace of the CS for the association between stimuli to be learned • Delayed conditioning is the most effective procedure for classical conditioning; trace conditioning can be effective provided the interval between stimuli is brief

11. A Summary of Classical Conditioning

12. The “Little Albert” Study • John Watson and Rosalie Rayner conducted a study on an 11-month-old infant named Albert • While Albert was looking at a little white rat, Watson quietly sneaked behind him with a long iron bar and a hammer and clanged the two together • Albert’s reflexive response, the UCR, was a fear-avoidance response (e.g., crying and trying to crawl away) to the loud noise, which was the UCS • After pairing the white rat with the unexpected loud noise only 7 times, the white rat became a CS

13. Other Evidence • Elise Bregman was unable to condition infants to fear inanimate objects such as wooden blocks and cloth curtains, suggesting possible biological predispositions to learn certain fears easier than others • Classical conditioning can be used to condition positive reactions, such as in advertising to condition positive attitudes and feelings toward certain products (e.g., a celebrity serves as a UCS, and the product as the CS)

14. General Learning Processes in Classical Conditioning • Acquisition is the process of acquiring a new response, that is, a CR to a CS • The strength of the CR increases during acquisition • Other processes: Extinction StimulusGeneralization SpontaneousRecovery StimulusDiscrimination

15. Extinction • A CS must reliably signal that the UCS is coming • Extinction is the disappearance of the CR when the UCS no longer follows the CS • The strength of the CR decreases during extinction

16. Spontaneous Recovery • During the extinction process, however, the CR mysteriously increases somewhat in strength following a rest interval • This is called spontaneous recovery • As extinction continues, the recovery observed following rest intervals continues to decrease until it is minimized

17. Acquisition, Extinction, and Spontaneous Recovery

18. Stimulus Generalization • Stimulus generalization is giving the CR to a stimulus similar to the CS • The more similar the stimulus is to the CS, the stronger the response will be • For example, if a dog learns to bark at the door bell, she may, at least in a new home, also bark at the telephone because both stimuli are ringing noises • This is an adaptive process because classical conditioning would not be very useful if it only allowed us to learn relationships between specific stimuli

19. Stimulus Discrimination • Overgeneralizing a response may not be adaptive, however; thus, we need to learn to discriminate among stimuli • Stimulus discriminationis learning to give the CR only to the CS or only to a small set of very similar stimuli including the CS • For example, after being in her new home for a period of time, the dog will learn to differentiate/discriminate between the door bell and the phone ringing noises

20. Discrimination Training • During discrimination training, you present many different stimuli numerous times, but the UCS only follows one CS • This procedure will extinguish the responses to other stimuli

21. Stimulus Generalization and Discrimination

22. Learning Through Operant Conditioning Learning Through Reinforcement and Punishment General Learning Processes in Operant Conditioning Partial-Reinforcement Schedules in Operant Conditioning Motivation, Behavior, and Reinforcement

23. Operant Conditioning Learning to associate behaviors with their consequences • Behaviors that are reinforced (lead to satisfying consequences) will be strengthened, and behaviors that are punished (lead to unsatisfying consequences) will be weakened • Called “operant” conditioning because the organism needs to “operate” on the environment to bring about consequences from which to learn

24. The Law of Effect • Thorndike’s Law of Effect states that any behavior that results in satisfying consequences tends to be repeated, and any behavior that results in unsatisfying consequences tends not be repeated

25. Learning Through Reinforcement and Punishment • A reinforcer is a stimulus that increases the probability of a prior response • Reinforcement is the process by which the probability of a response is increased by the presentation of a reinforcer following the response • For example, if you operantly condition your dog to bark by giving her a treat each time she “speaks,” the food would be a reinforcer, and the process of increasing the dog’s speaking behavior by using this reinforcer would be called reinforcement

26. Learning Through Reinforcement and Punishment • A punisher is a stimulus that decreases the probability of a prior response • Punishment is the process by which the probability of a response is decreased by the presentation of a punisher following the response • For example, if you conditioned your dog to stop getting up on the couch by spraying her with water each time she got up on the couch, the spraying would be the punisher, and the process of decreasing her couch jumping behavior would be called punishment

27. Positive and Negative • Positive means that a stimulus is presented • In both positive reinforcement and positive punishment, a stimulus presented • Negative means that a stimulus is removed • In both negative reinforcement and negative punishment, a stimulus is removed

28. Appetitive and Aversive • An appetitive stimulus is a stimulus that an organism finds pleasing (e.g., food, money) • An aversive stimulus is a stimulus that an organism finds unpleasing (e.g., sickness, social isolation)

29. Appetitive and Aversive • Consequently... • In positive reinforcement, an appetitive stimulus is presented (e.g., praise for good work) • In positive punishment, an aversive stimulus is presented (e.g., scolding for doing poor work) • In negative reinforcement, an aversive stimulus is removed (e.g., using a heating pad for a sore back) • In negative punishment, an appetitive stimulus is removed (e.g., parents taking away desert from a child)

30. Positive and Negative Reinforcement and Punishment

31. How do we know? • In any example of positive or negative reinforcement or punishment, it is critical to realize that we only know if a stimulus has served as a reinforcer or a punisher and led to reinforcement or punishment if the behavior happens again or stops happening

32. Primary and Secondary Reinforcers • A primary reinforcer is innately reinforcing since birth (e.g., food, social contact) • A secondary reinforcer is not innately reinforcing, but gains reinforcing properties through learning (e.g., money, good grades)

33. General Learning Processes in Operant Conditioning • Shapingoccurs when an animal is trained to make a particular response by reinforcing successively closer approximations to the desired response • With humans, this might mean reinforcing a child the closer he comes to making his bed correctly each morning • Responding in an operant conditioning experiment is depicted in a cumulative record – a record of the total number of responses over time • It is a visual depiction of the rate of responding • As the slope of a line in a cumulative record gets steeper, the response rate is faster

34. How to Understand a Cumulative Record

35. Acquisition, Extinction, and Spontaneous Recovery • Acquisition refers to the strengthening of the reinforced operant response • Extinction is the disappearance of the operant response when it is no longer reinforced • The decreasing slope of the record indicates that the response is being extinguished (i.e., there are fewer and fewer responses over time) • Spontaneous recovery is the temporary recovery of the operant response following a break during extinction training

36. Acquisition, Extinction, and Spontaneous Recovery

37. Vending Machines • We learn that by putting money into a vending machine, we get something we really like. We acquire the response of inserting money into this particular machine. • But one day, we put money in and get no food out. This happens again. Soon, we stop putting money in the vending machine. Our response is being extinguished. • However, after a period of time, we go back and try again (spontaneous recovery). If the machine has been repaired, we will get our food, and our response rate returns to its previous level. If not, we continue along our extinction trail.

38. Discrimination and Generalization • A discriminative stimulus is one that has to be present for the operant response to be reinforced • It “sets the occasion” for the response to be reinforced • For example, a rat learns that pressing a lever will result in food only when a light is on, but not when the light is off • Stimulus generalization is the giving the operant response in the presence of stimuli similar to the discriminative stimulus • For example, the rat learns to press the lever for food only when the light is a certain shade of red. Presentation of different colored lights following acquisition constitutes a test for generalization.

39. Partial-Reinforcement Schedules in Operant Conditioning • Reinforcing every response is called a continuous schedule of reinforcement • Partial schedules of reinforcement reinforce behavior only part of the time • The partial-reinforcement effect states that responses that are reinforced according to a partial schedule rather than a continuous schedule are more resistant to extinction

40. Partial-Reinforcement Schedules • A ratio schedule is based on the number of responses made • An interval schedule is based on the amount of time that has elapsed • In a fixed schedule, the number of responses required for a ratio schedule or the amount of time needed for an interval schedule is fixed • In a variable schedule, the number of responses required for a ratio schedule and amount of time for an interval schedule varies on each trial

41. Ratio Schedules • In a fixed ratio schedule, a reinforcer is delivered after a fixed number of responses are made (e.g., a rat has to press a lever 10 times before receiving the reinforcer of food) • In a variable ratio schedule, the number of responses it takes to obtain a reinforcer varies on each trial but averages out to be a certain number over trials (e.g., slot machine payoffs)

42. Fixed Ratio and Variable Ratio Schedules of Partial Reinforcement

43. Interval Schedules • In a fixed interval schedule, a reinforcer is delivered after the first response is given once a set interval of time has elapsed (e.g., periodic exams in a class, with most behaving/studying occurring right before the exam/reinforcer) • In a variable interval schedule, a reinforcer is delivered after a different time interval on each trial, but the time intervals over trials average to be a set time (e.g., pop quizzes)

44. Fixed Interval and Variable Interval Schedules of Partial Reinforcement

45. Which is best? • Ratio schedules lead to higher rates of responding than interval schedules (steeper slopes on the cumulative record) • Variable schedules lead to fewer breaks (no responding occurring) after reinforcement than fixed schedules • With respect to extinction, it will take longer to extinguish a response with a partial-reinforcement schedule than a continuous reinforcement

46. Motivation, Behavior, and Reinforcement Motivationis the set of internal and external factors that energize our behavior and direct it toward goals

47. Theories of Motivation • Drive-reduction theory proposes that first, a bodily need (such as hunger) creates a state of bodily tension called drive; then, a motivated behavior (seeking food) works to reduce this drive by obtaining reinforcement (food) to eliminate this need and return the body to a balanced internal state. • In essence, we are “pushed” into action by unpleasant drive states • Effective at explaining biological needs such as hunger and thirst

48. Theories of Motivation • Incentive theory proposes that we are “pulled” into action by incentives, external environmental stimuli that do not involve drive reduction • For instance, students may be motivated by getting good grades, leading them to work and study hard • Money is another classic example of an incentive that “pulls” us into behaving in certain ways

49. Theories of Motivation • Arousal theory contends that our behavior is motivated to maintain an optimal level of arousal, which varies among people • When below the optimal level, we are motivated to raise our arousal to that level • When over-aroused, we are motivated to lower our arousal level to our optimal level of arousal • Arousal theory argues that our level of arousal impacts our performance level, with a certain level being optimal

50. The Yerkes-Dodson’s Law Increased arousal will aid performance up to a point, after which further arousal impairs performance