Psychology: Brain, Mind, and Culture, 2e by Drew Westen Paul J. Wellman Texas A&M University John Wiley and Sons, Inc. PowerPoint  Presentation: Chapter 5 Learning

Lecture Outline n Learning  Classical Conditioning Acquisition Generalization versus discrimination Issues in classical conditioning  Operant Conditioning Positive versus negative reinforcement Schedules of reinforcement  Cognitive-social theory Expectancies and learning © 1999 John Wiley and Sons, Inc.

Learning n Learning: Refers to an enduring change in the way an organism responds based on its experience Distinct from –Drug effects (caffeine-iinduced jitters are not learning) –Fatigue or illness n Three assumptions of learning theories Responses are learned rather than innate Learning is adaptive Our experiments can uncover the laws of learning –These laws will apply to animals and to humans © 1999 John Wiley and Sons, Inc.

Classical Conditioning n The Russian physiologist Pavlov noted that reflexive salivation in dogs could be elicited by stimuli associated with feeding Reflex: Response that is reliably elicited by a stimulus –Food elicits salivation –Air puff elicits eye blink Reflexive stimulus and response are unconditioned Neutral stimulus is referred to as the conditioned stimulus (CS) CS is paired with the UCS over many trials Eventually comes to elicit a conditioned response (CR: resembles the UCR) © 1999 John Wiley and Sons, Inc.

Pavlov’s Experiment © 1999 John Wiley and Sons, Inc.

Conditioned Taste Aversion  If a flavor is followed by an illness experience, animals will not consume the flavor in the future CS + UCS > UCR Taste Toxic event Nausea CS -----> CR FlavorNausea © 1999 John Wiley and Sons, Inc.

Are These Examples of Classical Conditioning?  People smile to camera lights...  A man listening to the radio feels a rush when he hears a song that he and his fiance listened to on a number of occasions...  A cat runs into the kitchen when the can opener is turning...  A veteran dives to the street upon hearing a car backfire...  The smell of a steak produces salivation... © 1999 John Wiley and Sons, Inc.

Stimulus Generalization/Discrimination n Generalization: If a response is conditioned to one stimulus, the organism may also respond to a similar stimulus, but not to a dissimilar stimulus (discrimination)  Hovland study: CS + UCS > UCR Tone Shock Pain CS alone produced changes in GSR (associated with anxiety) © 1999 John Wiley and Sons, Inc.

Hovland Results: Stimulus Generalization © 1999 John Wiley and Sons, Inc. (Figure adapted from Hovland, 1937)

Acquisition and Extinction n Acquisition of classical conditioning: Requires pairing of CS and UCS n Extinction: Refers to the weakening of conditioning evident when the CS is presented repeatedly without the UCS (is diminished but not lost)  Spontaneous recovery: Refers to the reemergence of a previously extinguished CR © 1999 John Wiley and Sons, Inc.

Classical Conditioning Issues n Temporal order of CS and UCS is important Best conditioning: CS precedes UCS (forward) Worst conditioning: UCS precedes CS (backward) © 1999 John Wiley and Sons, Inc.

Classical Conditioning Issues n Interstimulus Interval between CS and UCS ISI’s longer than 2 sec produce poor conditioning n Prior conditioning history is important Latent Inhibition: Repeated exposure to a neutral stimulus alone (no UCS) makes it more difficult to use the stimulus as a CS in the future –Familiar ice cream taste is less likely to produce a CTA than a novel flavor © 1999 John Wiley and Sons, Inc.

Biological Preparedness: The Garcia Experiment © 1999 John Wiley and Sons, Inc. (Figure adapted from Garcia & Koelling, 1966)

Operant Conditioning n Law of Effect: Behavior is controlled by its consequences  Thorndike experiment: Hungry cat learned to pull a string in order to leave a box and eat food from a bowl placed just outside the box n Operant conditioning and instrumental conditioning: Responses operate on the environment and are instrumental in receiving reward © 1999 John Wiley and Sons, Inc.

Are These Examples of Operant Conditioning?  Woman inserts coins into a coke machine, presses the third button and receives five cans of soda. For the next week, she presses the third button on every coke machine she encounters...  Drug addict injects heroin into a vein…  Rat presses a lever to obtain food…  Woman pays $42.00 for groceries…  Man turns off television that was blaring an MTV video… © 1999 John Wiley and Sons, Inc.

Positive Reinforcement n Reinforcer: An environmental stimulus that occurs after the response and increases the likelihood that the response will occur in the future  Positive reinforcement: Process by which presentation of a stimulus after a response makes the response more likely to occur in the future  Negative reinforcement: Termination of an aversive event makes a behavior more likely to occur in the future © 1999 John Wiley and Sons, Inc.

Issues in Negative Reinforcement n Negative reinforcement assumes that a response that terminates an aversive stimulus will strengthen that response Taking an aspirin will reduce the headache and strengthen the behavior of aspirin-taking (sometimes referred to as escape-learning) Avoidance learning: A response prevents a potentially aversive event from occurring –Child cleans his room to avoid parental nagging © 1999 John Wiley and Sons, Inc.

Punishment n Punishment decreases the likelihood that a response will occur  Punishing situations: Presentation of an aversive stimulus (Positive) –Parent spanks a child for taking candy... –Owner swats a dog who has chewed her slippers... Removal of a reward (Negative) –Teenager who stays out past curfew is not allowed to drive the family car for 2 weeks... –Husband who forgets anniversary sleeps on couch for a week... © 1999 John Wiley and Sons, Inc.

Difficulties in Punishment n Learner may not understand which operant is being punished n Learner may come to fear the teacher rather than learn an association between the action and punishment (then avoids the teacher) n Punishment may not undo existing rewards for a behavior n Using punishment when the teacher is angry n Punitive aggression leads to future aggression © 1999 John Wiley and Sons, Inc.

Overview Of Conditioning

Schedules of Reinforcement n Continuous reinforcement: Reinforcer is obtained for every response  Intermittent schedules: Reinforcer is not obtained for every response Ratio Schedules –Fixed Ratio: Every Nth response –Variable Ratio: The average is every Nth response Interval Schedules: –Fixed Interval: After the elapse of N minutes –Variable Interval: On average, after N minutes © 1999 John Wiley and Sons, Inc.

Impact of Schedules of Reinforcement on Behavior © 1999 John Wiley and Sons, Inc.

Scallop Pattern in Humans © 1999 John Wiley and Sons, Inc. (Figure adapted from Weisberg & Waldrop, 1972, p. 23)

Tolman’s Study on Latent Learning © 1999 John Wiley and Sons, Inc. (Figure adapted from Tolman & Honzik, 1930, p. 267)

Expectancies and Conditioning  Cognitive-social theory argues that we form expectancies about the consequences of our behaviors These expectancies determine what is rewarding  Locus of control: Refers to general expectancy as to whether fate does or not determine outcomes in life Internal locus: Believe that their actions determine their fate External locus: Believe that their lives are governed by forces outside their control © 1999 John Wiley and Sons, Inc.

Locus of Control Scale (Figure adapted from Rotter, 1971)

Copyright Copyright 1999 by John Wiley and Sons, New York, NY. All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission of the copyright owner. © 1999 John Wiley and Sons, Inc.