Unformatted text preview: CHAPTER 6 LEARNING
Classical Conditioning Operant (Instrumental) Conditioning Cognitive Learning A DEFINITION OF LEARNING
Learning is a relatively permanent change in behavior or cognition (thinking, perception, and memory) as a result of practice or experience Ideas About Learning Determinism Nurture (Not Nature) Key Idea of Behaviorism Importance of Learning (Habits) (See Chap. 11 Learning and Personality) Kinds of Learning Classical Conditioning (Pavlov) Operant (Instrumental) Conditioning (Thorndike, Skinner) Cognitive Learning (Bandura and many others) Ivan P. Pavlov 1849 1936 pavlov2.jpg Pavlov's Demonstration Terminology Unconditioned Stimulus (UCS) Conditioned Stimulus (CS) Unconditioned Response (UCR) Conditioned Response (CR) ("Psychic Reflex") Figure 6.1 Classical conditioning apparatus. An experimental arrangement similar to the one depicted here (taken from Yerkes & Morgulis, 1909) has typically been used in demonstrations of classical conditioning, although Pavlov's original setup (see inset) was quite a bit simpler. The dog is restrained in a harness. A tone is used as the conditioned stimulus (CS), and the presentation of meat powder is used as the unconditioned stimulus (UCS). The tube inserted into the dog's salivary gland allows precise measurement of its salivation response. The pen and rotating drum of paper on the left are used to maintain a continuous record of salivary flow. (Inset) The less elaborate setup that Pavlov originally used to collect saliva on each trial is shown here (Goodwin, 1991). Figure 6.2 The sequence of events in classical conditioning. Moving from top to bottom, this series of diagrams outlines the sequence of events in classical conditioning, using Pavlov's original demonstration as an example. As we encounter other examples of classical conditioning throughout the book, we will see many diagrams like the one in the fourth panel, which summarizes the process. Figure 6.24 Conditioned taste aversion. Taste aversions can be established through classical conditionin as in the C sauce bCarnaise syndrome. CHowever, as the text explains, taste aversions can be acquired in ways that seem to violate basic principles of classi cal conditioning. g, Figure 6.3 Classical conditioning of a fear response. Many emotional responses that would otherwise be puzzling can be explained by classical conditioning. In the case of one woman's bridge phobia, the fear originally elicited by her father's scare tactics became a conditioned response to the stimulus of bridges. CLASSICAL CONDITIONING: MORE TERMINOLOGY Trial = pairing of UCS and CS Acquisition = initial stage in learning Stimulus contiguity = occurring together in time and space 3 types of Classical Conditioning Simultaneous conditioning: CS and UCS begin and end together Shortdelayed conditioning: CS begins just before the UCS, end together Trace conditioning: CS begins and ends before UCS is presented Backward conditioning not very Figure 6.9 Temporal relations of stimuli in classical conditioning. The effects of classical conditioning depend in part on the timing of the stimuli. Three ways of pairing the CS and UCS are diagrammed here. The most effective arrangement is short-delayed conditioning, in which the CS begins just before the UCS and stops at the same time as the UCS. PROCESSES IN CLASSICAL CONDITIONING Extinction Spontaneous Recovery Stimulus Generalization Discrimination Higherorder conditioning Figure 6.12 Generalization gradients. In a study of stimulus generalization, an organism is typically conditioned to respond to a specific CS, such as a 1200 hertz tone, and then tested with similar stimuli, such as other tones between 400 and 2000 hertz. Graphs of the organisms' responding are called generalization gradients. The graphs normally show, as depicted here, that generalization declines as the similarity between the original CS and the new stimuli decreases. When an organism gradually learns to discriminate between a CS and similar stimuli, the generalization gradient tends to narrow around the original CS. THE (IN)FAMOUS "LITTLE ALBERT" EXPERIMENTS Figure 6.13 Higher-order conditioning. Higher-order conditioning is a two-phase process. In the first phase, a neutral stimulus (such as a tone) is paired with an unconditioned stimulus (such as meat powder) until it becomes a conditioned stimulus that elicits the response originally evoked by the UCS (such as salivation). In the second phase, another neutral stimulus (such as a red light) is paired with the previously established CS, so that it also acquires the capacity to elicit the response originally evoked by the UCS. FROM THE FAMOUS MARGY KING Happiness is like jam. You can't spread even a little without getting some on yourself ... OPERANT CONDITIONING
INSTRUMENTAL CONDITIONING Operant Conditioning or Instrumental Learning Edward L. Thorndike (18741949) the law of effect B.F. Skinner (19041990) principle of reinforcement Operant chamber Emission of response Reinforcement contingencies Cumulative recorder Figure 6.14 The learning curve of one of Thorndike's cats. The inset shows one of Thorndike's puzzle boxes. The cat had to perform three separate actions to escape the box, including depressing the pedal on the right. The learning curve shows how the cat's escape time declined gradually over a number of trials. Figure 6.16 Skinner box and cumulative recorder. (a) This diagram highlights some of the key features of an operant chamber, or Skinner box. In this apparatus designed for rats, the response under study is lever pressing. Food pellets, which may serve as reinforcers, are delivered into the food cup on the right. The speaker and light permit manipulations of visual and auditory stimuli, and the electric grid gives the experimenter control over aversive consequences (shock) in the box. BASIC PROCESSES IN OPERANT CONDITIONING Acquisition Shaping Extinction Generalization Discrimination REINFORCEERS: CONSEQUENCES THAT STRENGTHEN RESPONSES Reinforcement is What Its All About Primary Reinforcers Secondary Reinforcers Schedules of Reinforcement Satisfy biological needs Greater Resistance to Extinction Types of Reinforcement
I NCREASES likelihood of behavior (strength of responding) Negative Reinforcement I NCREASES likelihood of behavior (strength of responding) Types of Punishment POSITIVE PUNISHMENT (strength of response) DECREASES likelihood of responding NEGATIVE PUNISHMENT ("TIME OUT") DECEASES likelihood of responding (strength of response) Figure 6.21 Positive reinforcement versus negative reinforcement. In positive reinforcement, a response leads to the presentation of a rewarding stimulus. In negative reinforcement, a response leads to the removal of an aversive stimulus. Both types of reinforcement involve favorable consequences and both have the same effect on behavior: The organism's tendency to emit the reinforced response is strengthened. Figure 6.23 Comparison of negative reinforcement and punishment. Although punishment can occur when a response leads to the removal of a rewarding stimulus, it more typically involves the presentation of an aversive stimulus. Students often confuse pun ishment with negative reinforcement because they associate both with aversive stimuli. However, as this diagram shows, punishment and negative reinforcement represent opposite procedures that have opposite effects on behavior. COGNITIVE LEARNING A Definition of Cognitive Learning StimulusStimulus (SS) Learning (Not SR or RS) Reinforcement not Necessary Learning of Relationships Learning Without Performance Examples of Cognitive Learning (AKA Perceptual Learning) Cognition in Classical and Operant Conditioning Cognitive Maps Latent Learning and Cognitive Maps (Tolman) Khler and insight learning Observational Learning (Bandura) The Bobo Doll Experiment Vicarious Reinforcement and Punishment Insight learning Khler and Sultan Gestalt and Perceptual Learning Figure 6.26 Observational learning. In observational learning, an observer attends to and stores a mental representation of a model's behavior (example: assertive bargaining) and its consequences (example: a good buy on a car). If the observer sees the modeled response lead to a favorable outcome, the observer's tendency to emit the modeled response will be strengthened. Two Bobos Vicarious Reinforcement and Punishment Violent TV ...
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