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Chapter 6 Learning 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 in part, of any images •Any rental, lease or lending of the program. • ISBN: 0-131-73180-7 Copyright © Allyn & Bacon 2007 Learning Learning – A process through which experience produces lasting change in behavior or mental processes • Learning vs. Instincts: • Nearly every human activity involves some form of learning. • Without learning, we would be forced to use only instincts. • Instinctive behavior (species-typical behavior) is heavily influenced by genetics. • Human behavior is much more influenced by learning and much less influenced by instincts than other animals. • Learning represents an evolutionary advance over instincts. Copyright © Allyn & Bacon 2007 Learning • Some types of learning can be quite simple. • Habituation – Learning not to respond to repeated presentation of a stimulus (ignoring sounds of heavy traffic ex.) Copyright © Allyn & Bacon 2007 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) Copyright © Allyn & Bacon 2007 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 Copyright © Allyn & Bacon 2007 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 becomes elicited by the conditioned stimulus Copyright © Allyn & Bacon 2007 The Essentials of Classical Conditioning Unconditioned stimulus (UCS) Unconditioned response (UCR) Conditioned stimulus (CS) Conditioned response (CR) Copyright © Allyn & Bacon 2007 The Essentials of Classical Conditioning Unconditioned stimulus (UCS) Unconditioned response (UCR) The stimulus that elicits an unconditioned response Conditioned stimulus (CS) Conditioned response (CR) Copyright © Allyn & Bacon 2007 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) Copyright © Allyn & Bacon 2007 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) Copyright © Allyn & Bacon 2007 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 unconditioned stimulus Copyright © Allyn & Bacon 2007 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) Copyright © Allyn & Bacon 2007 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 Copyright © Allyn & Bacon 2007 (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 Copyright © Allyn & Bacon 2007 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 Copyright © Allyn & Bacon 2007 Applications of Classical Conditioning Taste-aversion learning – Biological tendency in which an organism learns to avoid food with a certain taste after a single experience, if eating it is followed by illness Copyright © Allyn & Bacon 2007 A Challenge to Pavlov 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 Copyright © Allyn & Bacon 2007 How Do We Learn New Behaviors by Operant Conditioning? In operant conditioning, the consequences of behavior, such as rewards and punishments, influence the chance that our behavior will occur again Copyright © Allyn & Bacon 2007 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 Copyright © Allyn & Bacon 2007 Skinner’s Radical Behaviorism B.F. Skinner believed that the most powerful influences on behavior are its consequences Copyright © Allyn & Bacon 2007 The Power of Reinforcement Positive reinforcers – Stimulus presented after a response that increases the probability of that response happening again Negative reinforcers – Removal of an unpleasant stimulus, contingent on a particular behavior Copyright © Allyn & Bacon 2007 The Power of Reinforcement Primary reinforcers – Reinforcers, such as food and sex, that have an innate basis because of their biological value to an organism Copyright © Allyn & Bacon 2007 The Power of Reinforcement Secondary reinforcers – Stimuli, such as money or tokens, that acquire their reinforcing power by their learned association with primary reinforcers (also called conditioned reinforcers) Copyright © Allyn & Bacon 2007 Contingencies of Reinforcement Continuous reinforcement – Reinforcement schedule in which all correct responses are reinforced Partial reinforcement – Reinforcement schedule in which some, but not all, correct responses are reinforced (also called intermittent reinforcement) Copyright © Allyn & Bacon 2007 Contingencies of Reinforcement Extinction – In operant conditioning, a process by which a response that has been learned is weakened by the absence or removal of reinforcement How does this differ from extinction in classical conditioning? Copyright © Allyn & Bacon 2007 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) Copyright © Allyn & Bacon 2007 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) Copyright © Allyn & Bacon 2007 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) Copyright © Allyn & Bacon 2007 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 Copyright © Allyn & Bacon 2007 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 Copyright © Allyn & Bacon 2007 The Problem of Punishment Punishment – An aversive stimulus which diminishes the strength of the response it follows How does this differ from negative reinforcement? Copyright © Allyn & Bacon 2007 Punishment vs. Negative Reinforcement Negative Reinforcement Response Consequence Loud Noise Press Lever Loud Noise Removed Press Lever Loud Noise Applied Punishment No Noise Copyright © Allyn & Bacon 2007 The Problem of Punishment Positive punishment – The application of an aversive stimulus after a response Omission training (negative punishment) – The removal of an appetitive stimulus after a response Copyright © Allyn & Bacon 2007 Four Kinds of Consequences STIMULUS Positive or appetitive + Present Remove Positive Reinforcement Bonus for working hard leads to more hard work Negative or aversive Punishment Getting speeding ticket leads to less speeding Negative Reinforcement Omission Training Aspirin curing headache causes more aspirin use Missing dinner leads to less staying out late Copyright © Allyn & Bacon 2007 The Use and Abuse of Punishment Power usually disappears when threat of punishment is removed Punishment • • • Often triggers aggression May inhibit learning new and better responses Is often applied unequally When does punishment work? Copyright © Allyn & Bacon 2007 Alternatives to Punishment Extinction Reinforcing preferred activities Premack principle Prompting and shaping Copyright © Allyn & Bacon 2007 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 Copyright © Allyn & Bacon 2007 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 Copyright © Allyn & Bacon 2007 How Does Cognitive Psychology Explain Learning? Insight learning – Problem solving occurs by means of a sudden reorganization of perceptions Cognitive maps – A mental representation of physical space Copyright © Allyn & Bacon 2007 Observational Learning: Bandura’s Challenge to Behaviorism Observational learning – Form of cognitive learning in which new responses are acquired after watching others’ behavior and the consequences of their behavior Copyright © Allyn & Bacon 2007 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 Copyright © Allyn & Bacon 2007 End of Chapter 6 Copyright © Allyn & Bacon 2007