Learning. Learning Theories/Behaviorism. Watson s Extreme Environmentalism. A relatively permanent change in behavior brought about by experience

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1 Learning A relatively permanent change in behavior brought about by experience Watson s Extreme Environmentalism Give me a dozen healthy infants, well-formed, and my own special world to bring them up in, and I ll guarantee to take any one at random and train him to be any type of specialist I might select doctor, lawyer, artist, merchant-chief, and yes, beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors. Learning Theories/Behaviorism Habituation Pavlov: Classical Conditioning Watson Skinner: Operant Conditioning 1

2 Habituation Simplest form of learning Repeated exposure to a stimulus results in reduced responsiveness. Habituation Procedures Used to assess cognitive competence Declining interest indicates learning Novelty responsiveness indicates discrimination of new versus familiar Older infants habituate faster than younger infants Infants of same age require more time to encode complex stimuli than simple stimuli Habituation Procedures Orienting response: natural attentional response to new stimulus. Habituation: decline in orienting response as initially novel stimulus becomes familiar. Dishabituation: recovery of orienting response when an habituated stimulus changes. 2

3 Habituation Habituation Classical Conditioning An organism comes to associate one stimulus with another. Learning that one event predicts another. 3

4 Classical Conditioning Pavlov Unconditioned stimulus Unconditioned response Conditioned stimulus Conditioned response Pavlov s Original Experiment Classical Conditioning 4

5 Example You are in your dentist's office. Your dentist is looking at your x- rays, when he gets that far-off look that only dentists can get when they are looking at x-rays of The Big One! He turns to you, and with a half-sadistic, half-empathetic look, says, "My, my! I don't see cavities like this very often!" You hunker down, experiencing the drilling. Take notice of any changes in the way your body is reacting. Pay particular attention to bodily responses (remember, Pavlovian conditioning is about involuntary responses--those we do not have control over!). Example In this demonstration of the dentist's drill: Unconditional Reflex UCS drilling UCR - pain Conditional Reflex CS - sound of drill CR - pain Summary of General Principles of Classical Conditioning Any stimulus we can perceive has the potential to become a conditioned stimulus. Any response we make naturally can come to be elicited by any learned signal. These responses can be highly specific and simple (such as a muscle twitch or part of a brain wave pattern) or general and complex (such as fear). The conditioned response can be a response of our skeletal muscles or visceral organs or even a "private" response (such as thoughts and feelings). In other words, the response can be an overt behavior or reaction or something internal that only you know is happening. 5

6 Summary of General Principles of Classical Conditioning With a powerful original UCS, conditioning may take place in only one trial in which the UCS is paired with any CS. Stimuli quite different from the original CS can control the appearance of the conditioned response through second-order conditioning {DEF: transfer of CR from one CS to another CS. After you were salivating to Pavlov, I could have presented Pavlov and a light at the same time. Eventually, you would then salivate to just the light}. Depending on the strength of the CR and the nature of the conditioning process some learned responses resist extinction - don't fade away easily, and may endure a lifetime. This is good news if the response is something the person wants to continue doing, this is bad news if the behavior is destructive. Operant Conditioning The learning process by which a given behavior is changed by the consequences of that behavior. An organism learns to behave in ways that produce reinforcement. Watson, B. F. Skinner, Thorndike Watson Little Albert Experiment 0FKZAYt77ZM&feature=related 6

7 Consequences of Behavior Reinforcement When a consequence causes an increase in the performance of the behavior on which it is contingent. 7

8 Reinforcement Positive reinforcement: strengthening of a response whose consequence is a pleasant event. Negative reinforcement: strengthening of a response because it is followed by removal of an unpleasant event. Factors affecting Positive Reinforcement Selection of the behavior to be increased Choice of the reinforcer Immediacy Instructions Schedules of Reinforcement Schedules of Reinforcement Behavior is not necessarily going to be reinforced every time it occurs In real life, behavior is not often reinforced each time it occurs Intermittent reinforcement refers to reinforcement that is not administered to each instance of a response 8

9 Advantages of Intermittent Reinforcement Economizing on time and reinforcers Building persistent behavior which is much more resistant to extinction Types of Reinforcement Schedules *Continuous reinforcement: when each instance of a response is reinforced * Intermittment: when reinforcement is provided only after some, but not all occasions of a behaviour *Fixed ratio: when a certain number of responses occur prior to the delivery of the reinforcer (e.g., every 5 th time) *Variable ratio: varies the number of responses required around some average. *Fixed interval: reinforcement after some fixed length of time (e.g., after 30 seconds) *Variable interval: varies the length of time between reinforced responses around an average interval Schedules of Reinforcement Continuous reinforcement refers to reinforcement being administered to each instance of a response Intermittent reinforcement lies between continuous reinforcement and extinction 9

10 An Example of Continuous Reinforcement Each instance of a smile is reinforced Fixed Ratio Reinforcement A fixed number of responses is required for each reinforcement Example: every fourth instance of a smile is reinforced Graph of Fixed Ratio Responding 10

11 Fixed Interval Reinforcement These schedules require the passage of a specified amount of time before reinforcement will be delivered contingent on a response No response during the interval is reinforced The first response following the end of the interval is reinforced This schedule usually produces a scalloped pattern of responding in which little behavior is produced early in the interval, but as the interval nears an end, the rate of responding increases This also produces an overall low rate of responding Graph of Fixed Interval Responding Variable Schedules of Reinforcement Variable schedules differ from fixed schedules in that the behavioral requirement for reinforcement varies randomly from one reinforcement to the next This usually produces a more consistent pattern of responding without post-reinforcement pauses Variable ratio schedules produce an overall high consistent rate of responding Variable interval schedules produce an overall low consistent rate of responding 11

12 An Example of Variable Ratio Reinforcement Random instances of the behavior are reinforced Graph of Variable Ratio Responding Graph of Variable Interval Responding 12

13 Punishment When a consequence causes a decrease in the performance of a contingent behaviour Practice Giving a child a time-out Negative punishment Community service time cleaning up garbage Positive punishment Applause after outstanding concert performance Positive reinforcement You are freezing and put on a jacket Negative reinforcement 13

14 Shaping Process of teaching a complex behavior by rewarding closer and closer approximations of the desired behavior Limitations of Punishment Only suppresses existing behaviors Potential serious social consequences Learned helplessness Can lead to aggression/antisocial behaviors Only works in presence of punisher Using Punishment Effectively Punish as soon as possible Punish with appropriate amount of intensity Punish consistently Be otherwise warm Explain yourself Reinforce alternative behavior Consider alternative responses to misbehavior 14