Transcript Chapter 1
Chapter 5 Learning Chapter 5 Overview Classical conditioning – Learning through association of stimuli Operant conditioning – Learning through consequences Cognitive learning – Learning through mental processes Learning A relatively permanent change in behavior, knowledge, capability, or attitude that is acquired through experience and cannot be attributed to illness, injury, or maturation Classical Conditioning A type of learning through which an organism learns to associate one stimulus with another – A stimulus is any event or object in the environment to which an organism responds What type of learning did Pavlov discover, and how is it accomplished? Ivan Pavlov (1849-1936) discovered classical conditioning – Unconditioned stimulus (US) – Unconditioned response (UR) – Conditioned stimulus (CS) – Conditioned response (CR) What kind of learning did Pavlov discover, and how is it accomplished? Unconditioned stimulus (US) – Elicits an unconditioned response without learning e.g., food, loud noise, light in eye, puff of air in eye Unconditioned response (UR) – Response elicited by an unconditioned stimulus without learning e.g., salivation, startle, contraction of pupil, eyeblink What kind of learning did Pavlov discover, and how is it accomplished? Conditioned stimulus (CS) – Neutral stimulus that, after repeated pairing with US, becomes associated with it and elicits a conditioned response e.g., a tone Conditioned response (CR) – Learned response that comes to be elicited by a conditioned stimulus e.g., salivation in response to a tone Higher order conditioning – Occurs when conditioned stimuli are linked to form a series of signals What kinds of changes in stimuli and learning conditions lead to changes in conditioned responses? Extinction – Weakening and eventual disappearance of the CR as a result of repeated presentation of the CS without the US Spontaneous recovery – Reappearance of an extinguished CR when organism is exposed to the CS following a rest period What kinds of changes in stimuli and learning conditions lead to changes in conditioned responses? Generalization – Tendency to make a CR to a stimulus that is similar to the original CS Discrimination – Learned ability to distinguish between similar stimuli so that the CR occurs only to the original CS but not to similar stimuli How did Watson demonstrate that fear could be classically conditioned? Watson and Rayner (1920) “Little Albert” study Conditioned fears “persist and modify personality throughout life” Mary Cover Jones (1924) later used classical conditioning to remove fears in another boy According to Rescorla, what is the critical element in classical conditioning? Pavlov and Watson – Believed that the critical element of classical conditioning is repeated pairing of the CS and US Robert Rescorla – Showed that the critical element is whether the CS provides information that enables the organism to reliably predict the occurrence of the US How do biological predispositions affect classical conditioning? Biological predispositions affect classical conditioning – Organisms are biologically predisposed to rapidly acquire classically conditioned associations that enhance chances for survival Garcia and Koelling study (1966) Rats learned to associate nausea with flavored water, and electric shock with noise and lights But did not learn to associate nausea with noise and lights, or electric shock with flavored water Results demonstrated that animals are biologically predisposed to make certain associations but not others What types of everyday responses can be subject to classical conditioning? Why diet soda can make people hungry – Sweet taste of soda becomes a CS that elicits insulin increase, leading to feelings of hunger Advertising – An attractive celebrity (US) is associated with a product (CS) – After repeated pairings, the product elicits excitement (CR) Operant Conditioning A type of learning in which the consequences of behavior are manipulated so as to increase or decrease the frequency of an existing response or to shape an entirely new response What did Thorndike and Skinner discover about the effects of consequences on behavior? Edward Thorndike formulated the law of effect – The consequence, or effect, of a response determines whether the tendency to respond in the same way in the future is strengthened or weakened i.e., organisms tend to repeat behaviors that bring about pleasant consequences The law of effect formed the basis for B. F. Skinner’s work on operant conditioning What are the effects of positive reinforcement and negative reinforcement? Anything that follows a response and strengthens it or increases the probability that it will be repeated Positive reinforcement – A pleasant or desirable consequence that increases the probability that a response will be repeated Negative reinforcement – Termination of an unpleasant condition after a response, which increases the probability that the response will be repeated What are the effects of positive reinforcement and negative reinforcement? Primary reinforcer – A reinforcer that fulfills a basic physical need and does not depend on learning Secondary reinforcer – A reinforcer that is acquired or learned through association with other reinforcers What are the four types of schedules of reinforcement, and which type is most effective? Fixed-ratio (FR) – Reinforcer given after a fixed number of correct, nonreinforced responses Variable-ratio (VR) – Reinforcer is given after a varying number of nonreinforced responses Fixed-interval (FI) – Reinforcer is given after first correct response after a specific period of time has elapsed Variable-interval (VI) – Reinforcer is given after first correct response following a varying period of time What are the four types of schedules of reinforcement, and which type is most effective? Ratio schedules yield higher response rates than interval schedules – Fixed ratio schedule has highest response rate Variable schedules are most resistant to extinction What are the goals of shaping, extinction, generalization, and discriminative stimuli in the operant conditioning process? Shaping – Gradually molding a desired behavior (response) by reinforcing any movement in the direction of the desired response – Eventually, responses are guided toward the ultimate goal by rewarding successive approximations A series of gradual steps, each of which is more similar to the final desired response What are the roles of shaping, extinction, generalization, and discriminative stimuli in the operant conditioning process? Extinction – Weakening and eventual disappearance of a conditioned response as a result of withholding reinforcement Generalization – Tendency to make a learned response to a stimulus similar to that for which the response was originally reinforced Discriminative stimulus – Stimulus that signals whether a response or behavior is likely to be rewarded, ignored, or punished How does punishment affect behavior? Punishment is the removal of a pleasant stimulus or the application of an unpleasant stimulus, thereby lowering the probability of a response – Positive punishment Decrease in behavior that results from an added consequence – Negative punishment Decrease in behavior that results from a removed consequence The disadvantages of punishment It does not extinguish undesirable behavior, rather, it suppresses the behavior when the punishing agent is present It indicates that a behavior is unacceptable but does not help people develop more appropriate behavior The person who is punished often becomes fearful and feels angry toward the punisher It frequently leads to aggression Alternatives to punishment Removing the rewarding consequences of undesirable behavior may be the best way to extinguish it – Not giving in to a child’s demands during a tantrum – Ignoring misbehavior that is performed merely to get attention and giving attention to more appropriate behaviors Using positive reinforcement can make good behavior more rewarding Making punishment more effective Punishment is most effective when applied during the misbehavior or as soon afterward as possible Punishment should be of the minimum severity necessary to suppress the problem behavior To be effective, punishment must be applied consistently When is avoidance learning desirable, and when is it maladaptive? Escape learning – Learning to performing a behavior because it prevents or terminates an aversive event Avoidance learning – Learning to avoid events or conditions associated with aversive consequence – Can be adaptive Avoiding riding in a car with a driver who has been drinking – But much avoidance learning is maladaptive Avoiding situations because of phobias What are some applications of operant conditioning? Biofeedback – The use of sensitive equipment to give people precise feedback about internal physiological processes so that they can learn to exercise control over them Has been used to control migraine headaches, gastrointestinal disorders, asthma, anxiety, epilepsy, sexual dysfunctions, neuromuscular disorders, etc. What are some applications of operant conditioning? Behavior modification – Changing behavior based on the learning principles of classical conditioning, operant conditioning, or observational learning – Has been used to change self-injurious behavior in children and adults with autism Token economy – A program that motivates socially desirable behavior by reinforcing it with tokens Cognitive Learning Cognitive processes are mental processes such as thinking, knowing, problem solving, remembering, and forming mental representations – Behaviorists such as Watson and Skinner believed that learning could be explained without reference to internal mental processes – Today, however, most psychologists stress the role of mental processes by broadening the study of learning to include cognitive processes What is insight, and how does it affect learning? Insight – Sudden realization of the relationship between elements in a problem, which makes the solution apparent Köhler studies with chimpanzees – Chimpanzees who had given up attempts to get bananas suddenly returned with a solution – Their behavior seemed to be based on insight, not trial-and-error learning What did Tolman discover about the necessity of reinforcement? Latent learning – Learning that occurs without apparent reinforcement and is not demonstrated until the organism is motivated to do so Cognitive map – A mental representation of a spatial arrangement such as a maze What did Tolman learn about the necessity of reinforcement? Rats rewarded for running a maze after 11 days of nonreinforcement showed marked improvement the next day and outperformed rats that were rewarded daily These rats had learned the maze without reinforcement – They formed a cognitive map, but did not use it until they were reinforced What do we learn by observing others? Albert Bandura: Many behaviors are acquired through observational learning – Learning by observing the behavior of others and the consequences of that behavior; learning by imitation Model is the individual who demonstrates a behavior or whose behavior is imitated What do we learn by observing others? Modeling effect – Learning a new behavior from a model through the acquisition of new responses Facilitation effect – Exhibiting a behavior similar to that shown by a model in an unfamiliar situation Inhibitory effect – Suppressing a behavior because a model is punished for displaying the behavior Disinhibitory effect – Displaying a previously suppressed behavior because a model does so without receiving punishment What does research suggest about the effects of violence on television and in electronic games on viewers’ and players’ behavior? Bandura’s “Bobo Doll” studies – Children imitate aggressive behavior of an adult model seen on film Recent research – Individuals who watch the most violence as children are more likely to engage in acts of violence as adults Children also imitate prosocial behavior – As seen on shows such as Sesame Street What does research suggest about the effects of violence on television and in electronic games on viewers’ and players’ behavior? Recent research suggest that playing violent video games increases feelings of hostility and decreases sensitivity to violent images But, like television, video games can also teach positive messages and skills – Can teach teenagers to drive more safely – Can enhance spatial cognitive skills