Chapter 6: Learning How Nurture Changes Us Copyright © Allyn & Bacon 2009 Lecture Preview Discuss classical conditioning and how complex behaviors can arise from it Distinguish classical from operant conditioning, and the principles of reinforcement Explore the basis of observational and insight learning Discuss biological influences on learning Evaluate learning fads Copyright © Allyn & Bacon 2009 True or False? Once you reach adulthood, the brain is basically fixed and does not change. False. Recent evidence suggests that new neurons grow even in the adult brain, especially areas of the brain involved in learning. Copyright © Allyn & Bacon 2009 Basic Terminology Learning - change in an organism’s behavior or thought as a result of experience Habituation - process by which we respond less strongly over time to repeated stimuli Sensitization - process by which we respond more strongly over time (especially for dangerous, irritating stimuli) Eric Kandel earned the Nobel prize for his studies of habituation and sensitization in Aplysia (the sea slug) Copyright © Allyn & Bacon 2009 Classical Conditioning Ivan Pavlov - studied digestion in dogs, noted associative conditioning between neutral stimuli and meat powder (Pavlovian conditioning) Copyright © Allyn & Bacon 2009 Classical Conditioning Pavlov described classical conditioning, involving: UCS unconditioned stimulus - biologically significant stimulus that produces automatic response UCR unconditioned response - automatic response to a UCS that occurs without learning CS conditioned stimulus - initially neutral stimulus, becomes associated with the UCS through conditioning CR conditioned response - learned response By virtue of CS-UCS pairing, the CS comes to elicit the CR, a response closely related, but not identical, to the UR Copyright © Allyn & Bacon 2009 Pavlov’s Classical Conditioning Model Copyright © Allyn & Bacon 2009 Classical Conditioning Where do we see classical conditioning used everyday? Can you see how classical conditioning can explain how we learn prejudice? Copyright © Allyn & Bacon 2009 Classical Conditioning Aversive conditioning - classical conditioning to an unpleasant UCS Avoidance response Classical conditioning is adaptive in preparing the organism for the impending US Psychopathic personalities - indifferent to signals of threat Copyright © Allyn & Bacon 2009 Classical Conditioning Acquisition - learning phase during which a CR is established Extinction - gradual decrease and elimination of the CR when the CS is presented repeatedly without the UCS Copyright © Allyn & Bacon 2009 Classical Conditioning Spontaneous recovery - sudden reemergence of an extinguished CR after a delay Renewal effect - tendency of an extinguished CR to return when revisiting the original conditioning environment Phobias - intense and irrational fears Some acquired via classical conditioning Subject to spontaneous recovery and renewal Copyright © Allyn & Bacon 2009 Classical Conditioning Stimulus generalization - elicitation of a CR to stimuli that are highly similar to, but not identical to, the CS Generalization gradient - the more similar to the original CS the new CS is, the stronger will be the CR Stimulus discrimination - opposite of stimulus generalization; occurs when we exhibit a CR to certain CSs, but not others Copyright © Allyn & Bacon 2009 Applications of Classical Conditioning to Daily Life 1) Advertising - pairing positive USs with product CSs Latent inhibition - when we’ve experienced a CS alone many times, it’s difficult to classically condition it to another stimulus (e.g., highly known vs. novel brands) Copyright © Allyn & Bacon 2009 Applications of Classical Conditioning to Daily Life 2) Acquisition of fears: Little Albert Watson & Reyner (1920) sought to disprove the Freudian view of phobia, reflecting deep-seated unconscious conflict They recruited an infant, Albert, and paired a white rat (CS) with a loud clanging metal noise (UCS) Five days later, Albert exhibited fear of the rat, and similar stimuli, including a rabbit, dog, furry coat, and Santa Claus mask (generalization of phobia) Copyright © Allyn & Bacon 2009 Applications of Classical Conditioning to Daily Life: Little Albert Led to the conditioning model of phobias Classical conditioning also offers a way to get rid of phobia Mary Clover Jones (1924) successfully treated three-year-old Peter, who had a phobia of rabbits, by slowly introducing a rabbit paired with candies Similar exposure therapy is still the main behavioral treatment for irrational fears Copyright © Allyn & Bacon 2009 Applications of Classical Conditioning to Daily Life 3) Disgust reactions - in most cases, a product of classical conditioning because CSs associated with disgusting UCSs come to elicit disgust themselves Rozin (1986) subjects show a great reluctance to eat a piece of fudge shaped like dog feces Subjects show a great reluctance to drink a sucrose solution labeled poison, even when they put the meaningless label on there (“better safe than sorry” heuristic) Copyright © Allyn & Bacon 2009 Operant Conditioning Or instrumental conditioning - acquiring behaviors as a result of the outcome or consequence of those behaviors The organism gets something out of the response or “operates” on its environment (e.g., using biscuits as a treat, a trainer teaches a dog to sit) Copyright © Allyn & Bacon 2009 Differences Between Operant and Classical Conditioning Classical Response Elicited by UCS or CS Reward Independent of what the animal does Body System Often involves autonomic nervous system Operant Organism emits response in a seemingly voluntary fashion Organism must make response Copyright © Allyn & Bacon 2009 Often involves the skeletal muscles Law of Effect E. L. Thorndike (1898) studied cats in puzzle boxes, which led to the law of effect: If a response, in the presence of a stimulus, is followed by a satisfying state of affairs, the bond between stimulus and response will be strengthened According to Thorndike and others, learning involves an association between a stimulus and response (SR), with the reward stamping in this connection • Lack of insight in cats Copyright © Allyn & Bacon 2009 Thorndike’s Puzzle Box Copyright © Allyn & Bacon 2009 B. F. Skinner and Reinforcement Skinner developed a highly efficient conditioning chamber (Skinner box) that allows for conditioning and automated behavior measurement Typically contains bar that delivers food when pressed, food dispenser, and light that signals when reward is forthcoming Copyright © Allyn & Bacon 2009 Rat in Skinner Box and Electronic Device for Recording the Rat’s Behavior Copyright © Allyn & Bacon 2009 Terminology in Operant Conditioning Positive reinforcement - pleasant stimulus is given to increase the probability of a response (e.g., cell phone for good grades) Negative reinforcement - unpleasant stimulus is removed to increase the probability of a response (e.g., Aidan’s mother’s nagging stops when he picks up his room) Punishment - unpleasant stimulus is given, or pleasant stimulus is taken away, to decrease the probability of a response (e.g., cell phone taken away for breaking curfew) Copyright © Allyn & Bacon 2009 Punishment tends to be ineffective It tells the organism what not to do, rather than what to do Creates anxiety that can interfere with future learning Encourages subversive behavior (sneakiness) Provides a model for aggressive behavior Physical punishment is associated with aggression in adulthood: but what about the role of genetics? Copyright © Allyn & Bacon 2009 Principles of Reinforcement Partial reinforcement - behaviors that we reinforce only occasionally are slower to extinguish than those we reinforce continuously Schedules of reinforcement - pattern of reinforcing a behavior Fixed Ratio - after regular number of responses Variable Ratio - after specific number of responses, on average Fixed Interval - after specific amount of time Variable Interval - after an average time interval Copyright © Allyn & Bacon 2009 Applications of Operant Conditioning Shaping by successive reinforcement reinforcing behaviors that aren’t quite the target behavior but that are progressively closer versions of it Chaining - linking a number of interrelated behaviors to form a longer series Premack principle - a less frequently performed behavior can be increased by reinforcing it with a more frequent behavior Grandma’s rule - vegetables before dessert Copyright © Allyn & Bacon 2009 Applications of Operant Conditioning Superstitious behavior - behavior linked to reinforcement by sheer coincidence (e.g., lucky charm effect) Prejudice- how is it developed through operant conditioning? Token economies - mental hospital staff can reinforce patients who behave in a desired fashion using tokens, chips, points, or other secondary reinforcers Secondary reinforcers - neutral objects that patients can later trade in for… Primary reinforcers - items or outcomes that are naturally pleasurable, such as a favorite food or drink Copyright © Allyn & Bacon 2009 Applied Behavioral Analysis (ABA) ABA - a set of techniques, pioneered by Ivar Lovaas at UCLA, and based on operant conditioning principles, that relies on the careful measurement of behavior before and after implementing interventions Shaping techniques with primary reinforcers Children with autism treated with ABA show significant progress in language and intellectual skills Before Lovaas, many of these children would have been institutionalized Copyright © Allyn & Bacon 2009 Two-Process Theory: Putting Classical and Operant Conditioning Together Classical and operant conditioning are distinct in many ways, including underlying brain systems, but how they interact is called two-process theory People acquire phobias via classical conditioning, then avoid their feared stimulus (e.g., avoiding dogs after dog bite) This avoidance produces negative reinforcement, via anxiety reduction, maintaining the phobic response So phobias may involve classically conditioned fear AND operant avoidance Copyright © Allyn & Bacon 2009 Apply Your Thinking Sarah is afraid of flying. She prides herself on not taking any pills. What are some ways she may be able to enjoy flying more? Exposure therapy and extinction Positive reinforcement Copyright © Allyn & Bacon 2009 Other Forms of Learning Latent learning - learning that isn’t directly observable; we learn many things without showing them Emphasizes the difference between competence (what we know) and performance (showing what we know) Challenge to radical behaviorism, implies reinforcement isn’t necessary Copyright © Allyn & Bacon 2009 Other Forms of Learning Observational learning - learning by watching others (models), without instruction or reinforcement Brain basis? Perhaps mirror neurons Aggressive behavior: Bandura (1963) had children watch an adult ignoring or punching a Bobo doll and shouting things like “Kick him” Children who watched the aggressive adult model were aggressive to the Bobo doll later Copyright © Allyn & Bacon 2009 Media Violence Leads to Real-World Aggression? Scores of investigators have proposed that violent TV programs promote aggressiveness in children Correlation or causation? Longitudinal designs Laboratory experiments Field studies (e.g., examining aggression in a town with no TV) From these studies - media violence contributes to aggression in some circumstances Copyright © Allyn & Bacon 2009 Longitudinal Study of Individuals Who Watched Violent TV as Children Copyright © Allyn & Bacon 2009 Apply Your Thinking A school teacher is having trouble with Audrey hitting her classmates. He notifies the father, who spanks Audrey. The next day Audrey hits another classmate. When an adult angrily approaches her, she cowers in fear. What happened and what should the teacher do? Audrey demonstrated observational learning/modeling. Audrey shows classical conditioning of fear. The father should be taught that modeling good behavior and using reinforcement-based strategies will be more effective than punishment. Copyright © Allyn & Bacon 2009 Other Forms of Learning Kohler (1925) studied apes solving problems, in one case, reaching bananas by putting together two sticks that were not long enough individually Seemed evidence for “Aha!” phenomenon Insight learning - when subjects suddenly “get” the solution to a problem, and from there on get it right almost every time Copyright © Allyn & Bacon 2009 Biological Influences on Learning Preparedness regarding phobias suggests that we’re evolutionarily predisposed to fear certain stimuli more than others Monkeys are predisposed to become afraid of things such as toy snakes and alligators, but not toy flowers or rabbits About half of dog phobics have never had direct negative experience with a dog Classical conditioning does not account for all phobias Tendency for animals to return to innate behaviors following repeated reinforcement: instinctive drift Breland’s “coin washing” raccoons Copyright © Allyn & Bacon 2009 Learning Fads: Do They Work? Sleep-assisted learning - listening to audio tapes while you sleep Learn Morse code quicker? Better controlled studies suggested that the tapes awoke the subjects, they were not really asleep Accelerated learning - SALTT Discovery learning - giving students experimental materials and asking them to figure out scientific principles on their own Klahr (2004) - 3rd, 4th graders asked to figure out variables affecting how quickly a ball rolls down a ramp • Only 23% learned the principles using discovery learning, but 77% did with direct instruction Copyright © Allyn & Bacon 2009 Learning Styles: Fact or Fictional Fad? Do all individuals have their own distinctive learning styles? Analytical or spatial or verbal learners? Findings not reliable Studies show tailoring learning methods to a particular style doesn’t result in enhanced learning Most of us use a mixture of styles Copyright © Allyn & Bacon 2009 Apply Your Thinking One treatment for alcoholism is a drug (pill) called Antabuse® – it makes you very sick when you drink alcohol. Should this treatment work? Based on the principles we’ve discussed, why or why not? Yes, via conditioned taste aversion No, avoidance and noncompliance Copyright © Allyn & Bacon 2009