Chapter 5 Learning Yonghui Wang School of Psychology Shaanxi Normal University 2010.10.12 Chapter 5 Learning Learning is a fundamental topic for psychologists and plays a central role in almost every specialty area of psychology. 2016/3/22 2 Chapter 5 Learning Our goals: Identify four elements of Classical conditioning Explain these processes: extinction, spontaneous recovery, stimulus generalization, discrimination. Distinguish between classical and operant conditioning. Explain the principle of reinforcement. Define primary reinforcer and secondary reinforcer. Distinguish four schedules of reinforcement, and give examples of each. Distinguish positive reinforcement, negative reinforcement, punishment. Distinguish between cognitive learning and traditional theories of conditioning. 2016/3/22 3 Chapter 5 Outline What sort of learning does classical conditioning explain? How do we learn new behaviors by operant conditioning? How does cognitive psychology explain learning? 2016/3/22 4 What is learning? Learning: A lasting change in behavior or mental processes that results from experience. How do we know when a behavior has been influenced by learning——or even is a result of learning? Part of the answer relates to the naturenurture question. The acquisition of behaviors, experience is the “nurture” part. Inherited, genetic factors represent the “nature” part. 2016/3/22 5 What is learning? Some forms of learning Simple Habituation(习惯化) 2016/3/22 Habituation is an extremely simple form of learning, in which an animal or a baby, after a period of exposure to a stimulus, stops responding. Habituation is important in filtering the large amounts of information received from the surrounding environment. Mere exposure effect (单纯接触效应) (i.e. the advertising of McDonald’s) 6 What is learning? Some forms of learning Simple Classical conditioning(经典条件反射) Operant conditioning(操作条件反射) Cognitive learning(认知学习) 2016/3/22 7 Classical conditioning Classical conditioning(经典条件反射) is a basic form of learning in which a stimulus that produces an innate reflex becomes associated with a previously neural stimulus, which then acquires the power to elicit essentially the same response. Ivan Pavlov, a Russian physiologist 2016/3/22 8 Pavlov's Conditioning Experiments 2016/3/22 9 Classical conditioning Some important terms Neutral stimulus (NS) (中性刺激) Any stimulus that produces no conditioned response prior to learning. When it brought into a conditioning experiment, the researcher will call it a conditioned stimulus. Unconditioned stimulus (UCS, or US) (非条件刺激) The stimulus that elicits an unconditioned response (without having been learned). 2016/3/22 10 Classical conditioning Unconditioned response (UCR, or UR) (非条件反应) The response elicited by an unconditioned stimulus without prior learning (e.g., salivation at the smell of food). Conditioned stimulus (CS)(条件刺激) A once-neutral stimulus that has been paired with an unconditioned stimulus to bring about a response formerly caused only by the unconditioned stimulus. 2016/3/22 11 Classical conditioning Conditioned response (CR)(条件反应) A response elicited by a previously neutral stimulus that has become associated with the unconditioned stimulus ( e.g., salivation at the ringing of a bell). 2016/3/22 12 Classical conditioning Can you give some examples of classical conditioning? 2016/3/22 13 Phases of Classical Conditioning 2016/3/22 14 Elements of Classical Conditioning Unconditioned stimulus Unconditioned response Response to unlearned stimulus Conditioned stimulus Unlearned, inborn, innate Stimulus that is learned Conditioned response Response to learned stimulus Can you figure out the relationship between stimuli and responses? 2016/3/22 15 Components of Classical Conditioning Acquisition(习得) The initial learning stage in classical conditioning, during which the conditioned response comes to be elicited by the conditioned stimulus. Stimulus Generalization (泛化) The extension of a learned response to stimuli that are similar to but different from the conditioned stimulus. for example 2016/3/22 16 Components of Classical Conditioning Stimulus Discrimination (分化) A change in responses to one stimulus but not to stimuli that are similar. for example Extinction(消退) The weakening of a conditioned response in the absence of an unconditioned stimulus. for example 2016/3/22 17 Components of Classical Conditioning Has it vanished forever once a conditioned response has been extinguished? Good news: not necessary. Spontaneous Recovery(自发恢复) The reappearance of an extinguished conditioned response after a time delay. 2016/3/22 18 Components of Classical Conditioning Spontaneous Recovery(自发恢复) Extinction Acquisition 2016/3/22 Spontaneous recovery 19 Applying Conditioning Principles to Human Behavior Can you recall some Applications of classical conditioning? 2016/3/22 20 Challenging basic assumptions Recall the classical conditioning first Cognitive psychology Learns actively develop an expectancy about the relationship between the unconditioned stimuli and conditioned stimuli. 2016/3/22 21 Learning psychology (John Garcia) The experience of the rats a)violated one of the basic rules—that an unconditioned stimulus should immediately follow a conditioned stimulus. The interval can as long as eight hours. b)The conditioning sometimes occurred after just one exposure to water that was followed later on by illness. 2016/3/22 22 Classical Conditioning Is Selective Research demonstrating that we develop phobias about snakes and spiders, for example, but almost never about flowers or cooking utensils illustrates Seligman's principles of preparedness and contrapreparedness, respectively. The ease with which we develop conditioned food (or taste) aversions also illustrates learning preparedness. 2016/3/22 23 Conditioned food aversions are exceptions to the general rules about classical conditioning. Animals can learn to avoid poisonous food even if there is a lengthy interval between eating the food and becoming ill. In many cases, only one pairing of conditioned and unconditioned stimuli is necessary for learning to take place. 2016/3/22 24 Thorndike's law of effect Look at this experiment at first. Law of effect (效果律) 2016/3/22 25 Skinner’s box 2016/3/22 26 Operant Conditioning Operant conditioning, or instrumental conditioning is learning in which a voluntary response is strengthened or weakened, depending on its favorable or unfavorable consequences. 2016/3/22 27 Components of Operant Conditioning Reinforcement and Reinforcer (强化和强化物) Punishment(惩罚) Positive reinforcement and positive reinforcers Negative reinforcement and negative reinforcers The punishment dilemma(惩罚的两难选择) Shaping(塑造) The process of teaching a complex behavior by rewarding closer and closer approximations of the desired behavior. 2016/3/22 28 Reinforcement and Reinforcer Reinforcement The process by which a stimulus increases the probability that a preceding behavior will be repeated. Reinforcer Any stimulus that increases the probability that a preceding behavior will occur again. 2016/3/22 29 Reinforcement and Reinforcer Positive reinforcer A stimulus added to the environment that brings about an increase in a preceding response. Negative reinforcer An unpleasant stimulus whose removal leads to an increase in the probability that a preceding response will occur again in the future. 2016/3/22 30 Reinforcement and Reinforcer Primary reinforcer A reinforcer that can satisfy a basic biological need, most likely food or water. Secondary reinforcers The reinforcers that do not satisfy a basic biological need but acquire their rewarding power by association with another established reinforcer. 2016/3/22 31 Punishment The pros and cons of punishment Advantage Should be swift, sufficient Protection Disadvantage 2016/3/22 Not as effective as reinforcement Not usually permanent Not convey any information of alternative behavior May result in anxiety of aggressive behavior 32 Punishment Question When should we use punishment and when the reinforcer? 2016/3/22 33 Schedules of Reinforcement Continuous reinforcement(持续强化) Partial reinforcement(部分强化) Fixed-ratio schedule(比率固定) Variable-ratio schedule(比率不定) Fixed-interval schedule(间隔固定) Number of responses Variable-interval schedule (间隔不定) Amount of time Can you give examples of each schedule? 2016/3/22 34 Schedules of Reinforcement What are the characters of each schedule? Which one is better? Can you design a plan for more efficiency? 2016/3/22 35 The Application of Operant Conditioning Computer-Assisted Instruction (CAI)(计算机辅助教 学) Students learn at their own rate, using computers that are programmed to deliver individual instruction. Behavior Modification(行为矫正) A formalized technique for promoting the frequency of desirable behaviors and decreasing the incidence of unwanted ones. 2016/3/22 36 Comparing Classical And Operant Conditioning Similarities involve associations between stimuli and responses subject to extinction and spontaneous recovery as well as generalization and discrimination. 2016/3/22 37 Comparing Classical And Operant Conditioning Differences The stimuli is before response in Classical Conditioning, while stimuli is after response in Operant Conditioning. The stimuli (food) in Classical Conditioning is using as UCS, while stimuli is after response serve as a reinforce in Operant Conditioning. The response is more ”voluntary” in Operant Conditioning. 2016/3/22 38 Cognitive-Social Approaches to Learning Latent Learning and Cognitive Maps Learning takes place before the subject realizes it Cognitive map is latent learning stored as a mental image Insight and Learning Sets Learning seems to occur in a “flash” with insight Learning sets refer to increasing effectiveness at problem solving through experience 2016/3/22 39 Cognitive-Social Approaches to Learning Learning by Observing Observational or vicarious learning(观察学习或替 代学习) Social learning theorists Vicarious reinforcement or vicarious punishment 2016/3/22 40 Learning by Observing 2016/3/22 41 Learning by Observing Results 2016/3/22 42 Learning by Observing Social learning theory argues that we learn not just from firsthand experience, but also from watching others or by hearing about something. Albert Bandura contends that observational (or vicarious) learning accounts for many aspects of human learning. The extent to which we display behaviors that have been learned through observation can be affected by vicarious reinforcement and vicarious punishment. 2016/3/22 43