Copyright © 2005 Pearson Education Canada Inc. Learning Chapter 5
Copyright © 2005 Pearson Education Canada Inc. Learning Learning is a relatively permanent change in an organism. Learning occurs as a result of experiences in the environment Psychologists study the results of learning by examining overt behaviour or by measuring physiological changes
Copyright © 2005 Pearson Education Canada Inc. Operant Conditioning In the 1930s, B. F. Skinner questioned whether Pavlovian (classical) conditioning should be studied Skinner felt behaviour can be explained through operant conditioning
Copyright © 2005 Pearson Education Canada Inc. Operant Conditioning In operant conditioning, the probability a behaviour will increase or decrease depends on the reinforcement or punishment that follows (a consequence)
Copyright © 2005 Pearson Education Canada Inc. Operant Conditioning Thorndike placed hungry cats in boxes and the cats quickly learned to escape by hitting a lever giving them access to food Thorndike called this instrumental (or operant) conditioning, because the cats’ behaviour was instrumental in gaining reward
Copyright © 2005 Pearson Education Canada Inc. The Skinner Box Much of the research on operant conditioning is performed with a Skinner box This is a box containing a responding mechanism (a lever or bar that an animal can press) A consequence is delivered to the animal following a desired response
Copyright © 2005 Pearson Education Canada Inc. Shaping Teaching an organism a complex response often involves shaping Shaping is the selective reinforcement of behaviours that gradually approach (approximate) a desired response
Copyright © 2005 Pearson Education Canada Inc. Figure 5.7 The Process of Operant Conditioning
Copyright © 2005 Pearson Education Canada Inc. Reinforcement In operant conditioning, the consequences of behaviour can be a reinforcer or punisher A reinforcer is any event that increases the probability of the recurrence of the response that preceded it
Copyright © 2005 Pearson Education Canada Inc. Reinforcement Negative reinforcement is the removal of a stimulus after a particular response to increase the likelihood the response will recur Positive reinforcement is the presentation of a stimulus after a behaviour that increases the likelihood that response will recur
Copyright © 2005 Pearson Education Canada Inc. Reinforcement Noxious or unpleasant stimuli are often used in animal studies of escape and avoidance In escape conditioning, a rat in a Skinner box receives a painful shock When the rat moves around while being shocked, it eventually hits a bar, which shuts the shock off
Copyright © 2005 Pearson Education Canada Inc. Reinforcement In avoidance conditioning, the shock is preceded by a buzzer
Copyright © 2005 Pearson Education Canada Inc. The Nature of Reinforcers A primary reinforcer has survival value and does not need to be learned A secondary reinforcer is initially a neutral stimulus with no intrinsic value
Copyright © 2005 Pearson Education Canada Inc. Superstitious Behaviours When a person or animal is accidentally rewarded, superstitious behaviour may develop
Copyright © 2005 Pearson Education Canada Inc. Electrical Brain Stimulation James Olds found that rats find electrical stimulation of specific brain areas to be rewarding Olds found rats pressed the lever thousands of times to produce such self- stimulation Neurotransmitters are believed to play a role in this effect
Copyright © 2005 Pearson Education Canada Inc. Punishment: Weakening Responses Punishment decreases the probability that a response will occur Positive punishment is when an unpleasant stimulus is added in an effort to decrease an undesirable behaviour Negative punishment is when a pleasant stimulus is taken away
Copyright © 2005 Pearson Education Canada Inc. The Nature of Punishers A primary punisher is a stimulus that is naturally painful or unpleasant A secondary punisher is a neutral stimulus that initially has no intrinsic negative value
Copyright © 2005 Pearson Education Canada Inc. Punishment Plus Reinforcement Punishment by itself is not an effective way to eliminate or control behaviour An effective way of controlling behaviour is to punish the undesirable behaviour, while reinforcing a desirable one Inconsistent punishment may lead to learned helplessness or giving up and not responding
Copyright © 2005 Pearson Education Canada Inc. Key Variables in Operant Conditioning The strength of the consequences of a behaviour is a key factor in operant conditioning The timing of the consequences or the interval between a behaviour and its consequences increase the likelihood a behaviour will be learned
Copyright © 2005 Pearson Education Canada Inc. Key Variables in Operant Conditioning Frequency of consequences is another key factor Continuous reinforcement is reinforcement for every occurrence of the behaviour Partial reinforcement is occasional or intermittent
Copyright © 2005 Pearson Education Canada Inc. Key Variables in Operant Conditioning Fixed interval schedule is when a reward is delivered after a specified interval of time provided a response occurs at least once Variable interval schedule is when a reward is delivered after a predetermined but varying interval of time provided a response occurs at least once after each interval
Copyright © 2005 Pearson Education Canada Inc. Key Variables in Operant Conditioning Variable ratio schedule is when a reward is delivered after a specified number of responses has occurred Variable ratio schedule is when a reward is delivered after a predetermined but variable number of responses has occurred
Copyright © 2005 Pearson Education Canada Inc. Figure 5.11 The Four Basic Types of Reinforcement Schedules
Copyright © 2005 Pearson Education Canada Inc. Stimulus Generalization and Stimulus Discrimination Stimulus generalization and stimulus discrimination occur in operant conditioning, just as they do in classical conditioning However, in operant conditioning, the reinforcement is delivered only after the animal discriminates correctly
Copyright © 2005 Pearson Education Canada Inc. Extinction In operant conditioning, extinction means the probability of an organism’s emitting a response is reduced when reinforcement no longer follows a response One way to measure the extent of conditioning is through resistance to extinction or how many trials are needed before extinction occurs
Copyright © 2005 Pearson Education Canada Inc. Spontaneous Recovery As in classical conditioning, spontaneous recovery also occurs
Copyright © 2005 Pearson Education Canada Inc. Operant Conditioning in Daily Life Some behaviours are intrinsically rewarding People perform externally motivated behaviours for the sake of external reinforcement only Behavioural self-regulation assumes activities are chosen that seem optimal