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Chapter 3 Learning and Human Nature This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network; preparation of any derivative work, including the extraction, in whole or part, of any images; any rental, lease, or lending of the program. ISBN: 0-205-42428-7 1 Copyright © Allyn and Bacon 2009 Learning vs. Instincts Learning – A process through which experience produces lasting change in behavior or mental processes HabituationLearning not to respond to stimulation InstinctsMotivated behaviors that have a strong innate basis 2 Copyright © Allyn and Bacon 2009 Learning Mere exposure effect – Learned preference for stimuli to which we have been previously exposed Behavioral learning – Forms of learning that can be described in terms of stimuli and responses (e.g. classical and operant conditioning) 3 Copyright © Allyn and Bacon 2009 What Sort of Learning Does Classical Conditioning Explain? Classical conditioning is a basic form of learning in which a stimulus that produces an innate reflex becomes associated with a previously neutral stimulus, which then acquires the power to elicit essentially the same response 4 Copyright © Allyn and Bacon 2009 The Essentials of Classical Conditioning Neutral stimulus – Any stimulus that produces no conditioned response prior to learning Acquisition – Initial learning stage in classical conditioning • conditioned response (CR) becomes elicited by the conditioned stimulus (CS) 5 Copyright © Allyn and Bacon 2009 Basic Features of Classical Conditioning Unconditioned stimulus (UCS) Unconditioned response (UCR) Conditioned stimulus (CS) Conditioned response (CR) 6 Copyright © Allyn and Bacon 2009 7 Copyright © Allyn and Bacon 2009 The Essentials of Classical Conditioning Unconditioned stimulus (UCS) Unconditioned response (UCR) The stimulus that elicits an unconditioned response Conditioned stimulus (CS) Conditioned response (CR) 8 Copyright © Allyn and Bacon 2009 The Essentials of Classical Conditioning Unconditioned stimulus (UCS) Unconditioned response (UCR) Conditioned stimulus (CS) The response elicited by an unconditioned stimulus without prior learning Conditioned response (CR) 9 Copyright © Allyn and Bacon 2009 The Essentials of Classical Conditioning Unconditioned stimulus (UCS) Unconditioned response (UCR) Conditioned stimulus (CS) A previously neutral stimulus that comes to elicit the conditioned response Conditioned response (CR) 10 Copyright © Allyn and Bacon 2009 The Essentials of Classical Conditioning Unconditioned stimulus (UCS) Unconditioned response (UCR) Conditioned stimulus (CS) Conditioned response (CR) A response elicited by a previously neutral stimulus that has become associated with the conditioned stimulus 11 Copyright © Allyn and Bacon 2009 Classical Conditioning Prior to conditioning Neutral stimulus (tone) (Orientation to sound but no response) Unconditioned stimulus (food powder in mouth) Unconditioned response (salivation) Conditioning Neutral stimulus CS (tone) + Unconditioned stimulus (food powder) Conditioned response (salivation) After conditioning Conditioned stimulus (tone) Conditioned response (salivation) 12 Copyright © Allyn and Bacon 2009 Classical Conditioning Extinction – Weakening of a conditioned association in the absence of an unconditioned stimulus or reinforcer Spontaneous recovery – Reappearance of an extinguished conditioned response after a time delay 13 Copyright © Allyn and Bacon 2009 (1) Acquisition (CS + UCS) (2) Extinction (CS alone) Rest period Strength of the CR (Weak) (Strong) Acquisition, Extinction, and Spontaneous Recovery (3) Spontaneous Recovery (CS alone) (Time) Trials 14 Copyright © Allyn and Bacon 2009 Classical Conditioning: Generalization and Discrimination Stimulus generalization involves giving a conditioned response to stimuli that are similar to the CS Stimulus discrimination involves responding to one stimulus but not to stimuli that are similar Confusing stimuli may cause experimental neurosis 15 Copyright © Allyn and Bacon 2009 Applications of Classical Conditioning Conditioned Food Aversions– Biological tendency in which an organism learns to avoid food with a certain sight, smell, or taste after a single experience, if eating it is followed by illness 16 Copyright © Allyn and Bacon 2009 Biological Predispositions: A Challenge to Pavlov Garcia & Koelling (1966) findings• Selective CS-UCS connection • Innate disposition to associations Why are some stimuli-consequence combinations readily learned while other combinations are highly resistant to learning? What any organism can or cannot learn in a given setting is due in part to its evolutionary history 17 Copyright © Allyn and Bacon 2009 How Do We Learn New Behaviors by Operant Conditioning? In operant conditioning, the consequences of behavior, such as rewards and punishments, influence the probability that the behavior will occur again 18 Copyright © Allyn and Bacon 2009 How Do We Learn New Behaviors by Operant Conditioning? Trial-and-error learning – Learner gradually discovers the correct response by attempting many behaviors and noting which ones produce the desired consequences Thorndike-law of effect 19 Copyright © Allyn and Bacon 2009 Skinner’s Radical Behaviorism B.F. Skinner believed that the most powerful influences on behavior are its consequences “The power of reinforcement” • reward = conditions that follow and strengthen a response • Operant chamber 20 Copyright © Allyn and Bacon 2009 21 Copyright © Allyn & Bacon 2009 The Power of Reinforcement Positive reinforcers – Stimulus presented after a response that increases the probability of that response happening again • Positive = add or apply Negative reinforcers – Removal of an unpleasant stimulus, that increases the probability of that response happening again • Negative = subtract or remove 22 Copyright © Allyn and Bacon 2009 Contingencies of Reinforcement: Varying the timing and frequency of reinforcement Continuous reinforcement – Reinforcement schedule in which all correct responses are reinforced Partial (intermittent) reinforcement – Reinforcement schedule in which some, but not all, correct responses are reinforced 23 Copyright © Allyn and Bacon 2009 Schedules of Reinforcement Ratio schedules – Provide reward after a certain number of responses Interval schedules – Provide reward after a certain time interval Fixed Ratio (FR) Variable Ratio (VR) Fixed Interval (FI) Variable Interval (VI) 24 Copyright © Allyn and Bacon 2009 Schedules of Reinforcement Fixed Ratio (FR) Variable Ratio (VR) Fixed Interval (FI) Rewards appear after a certain set number of responses e.g. factory workers getting paid after every 10 cases of product are completed Variable Interval (VI) 25 Copyright © Allyn and Bacon 2009 Schedules of Reinforcement Fixed Ratio (FR) Variable Ratio (VR) Fixed Interval (FI) Rewards appear after a certain number of responses, but that number varies from trial to trial e.g. slot machine payoffs Variable Interval (VI) 26 Copyright © Allyn and Bacon 2009 Schedules of Reinforcement Fixed Ratio (FR) Variable Ratio (VR) Fixed Interval (FI) Variable Interval (VI) Rewards appear after a certain fixed amount of time, regardless of number of responses e.g. weekly or monthly paychecks 27 Copyright © Allyn and Bacon 2009 Schedules of Reinforcement Fixed Ratio (FR) Variable Ratio (VR) Fixed Interval (FI) Variable Interval (VI) Rewards appear after a certain amount of time, but that amount varies from trial to trial e.g. random visits from the boss who delivers praise 28 Copyright © Allyn and Bacon 2009 The Power of Reinforcement Primary reinforcers – Reinforcers that fulfill basic biological needs or desires, such as food and sex, that have an innate basis to an organism 29 Copyright © Allyn and Bacon 2009 The Power of Reinforcement Secondary (conditioned) reinforcers – Stimuli, such as money or tokens, that acquire their reinforcing power by their learned association with primary reinforcers 30 Copyright © Allyn and Bacon 2009 Factors that can influence the effectiveness of reinforcement Instinctive driftinnate response tendencies interfere with learned behaviors; innate tendencies can override behaviors learned through reinforcement e.g., reinforcing your cat to not scratch the furniture Premack principlea preferred activity can reinforce a less preferred activity e.g., children sitting quietly in class in order to go out for recess 31 Copyright © Allyn and Bacon 2009 Punishment Punishment – An aversive stimulus which diminishes the strength of the response it follows How does this differ from negative reinforcement? 32 Copyright © Allyn and Bacon 2009 Punishment vs. Negative Reinforcement Negative Reinforcement Response Consequence Loud Noise Press Lever Loud Noise Removed Press Lever Loud Noise Applied Punishment No Noise 33 Copyright © Allyn and Bacon 2009 Types of Punishment Positive punishment – The application or presentation of an aversive stimulus after a response Negative punishment – The removal of an attractive stimulus after a response Both attempt to decrease the likelihood that a behavior will reoccur 34 Copyright © Allyn and Bacon 2009 Four Kinds of Consequences GOAL STIMULUS Increase Behavior Decrease Behavior Positive (Add) Negative (Subtract) Positive Reinforcement Negative Reinforcement Bonus for working hard Aspirin relieving headache leads to more hard work leads to more aspirin use Positive Punishment Positive Punishment Getting speeding ticket leads to less speeding Missing dinner leads to less staying out late 35 Copyright © Allyn and Bacon 2009 The Use of Punishment Punishment can result in immediate change in behavior, often making it an easy solution; should be a logical consequence to make it work 36 Copyright © Allyn and Bacon 2009 The Abuse of Punishment Problems associated with punishment: • Power of use usually disappears when threat of punishment is removed • Rewards can override/overpower the punishment • Often triggers escape or aggression • Teaches legitimate use of aggression to influence others • May inhibit learning new and better responses • Is often applied unequally 37 Copyright © Allyn and Bacon 2009 When does punishment work? • when presented without delay • when consistent • when limited in duration and intensity • when consequence is logical • limited to the specific situation at hand • when no mixed messages are sent • when negative punishment is used 38 Copyright © Allyn and Bacon 2009 A checklist for Modifying Operant Behavior Consider combining the following: Positive reinforcement -encourage desirable behaviors Punishment -use logical consequences, swiftly, without undue harm Negative reinforcement Extinction -control all possible reinforcers 39 Copyright © Allyn and Bacon 2009 Inset table to illustrate comparison of Classical and Operant Conditioning (pg. 3-40) 40 Copyright © Allyn and Bacon 2009 Operant and Classical Conditioning Compared Classical conditioning involves the association of two stimuli (UCS + CS) before the response or behavior Operant conditioning involves a reinforcing (reward) or punishing stimulus after a response or behavior 41 Copyright © Allyn and Bacon 2009 42 Copyright © Allyn & Bacon 2009 How Does Cognitive Psychology Explain Learning? According to cognitive psychology, some forms of learning must be explained as changes in mental processes, rather than as changes in behavior alone 43 Copyright © Allyn and Bacon 2009 How Does Cognitive Psychology Explain Learning? Insight learning – Problem solving occurs by suddenly perceiving new forms or relationships Cognitive maps – A mental image used to navigate through a familiar environment 44 Copyright © Allyn and Bacon 2009 How Does Cognitive Psychology Explain Learning? Latent learningwhen learning occurs without reinforcement and without any hint that learning took place cognitive explanation of learning vs. the behavioral explanation 45 Copyright © Allyn and Bacon 2009 Observational Learning: Bandura’s Challenge to Behaviorism Observational learning (social learning)– • form of cognitive learning • new responses are acquired after watching others’ behavior and consequences of their behavior 46 Copyright © Allyn and Bacon 2009 Rethinking Behavioral Learning in Cognitive Terms Cognitive-behavioral psychologists • associations occur when the organism is seen as an information seeker using logical and perceptual relations among events • reinforcement changes expectations for future rewards or punishments 47 Copyright © Allyn and Bacon 2009 Brain Mechanisms and Learning Long-term potentiation – • Biological process involving physical changes that strengthen the synapses in groups of nerve cells • believed to be the neural basis of learning 48 Copyright © Allyn and Bacon 2009 Brain Mechanisms and Learning Extinction• forgetting unimportant associations • neurotransmitters block memories • glutamate; norephinephrine 49 Copyright © Allyn and Bacon 2009 Brain Mechanisms and Learning Learning circuitry• Simpler circuits • Classical conditioning and operant learning • Complex learning• Concept formation, insight learning, and observational learning 50 Copyright © Allyn and Bacon 2009 Brain Mechanisms and Learning Observational learning and mirror neurons • Neurons that help us imitate others’ behaviors 51 Copyright © Allyn and Bacon 2009