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Psychology: From Inquiry to Understanding 2/e Scott O. Lilienfeld Steven Jay Lynn Laura Namy Nancy J. Woolf Prepared by Caleb W. Lack This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmis...
Psychology: From Inquiry to Understanding 2/e Scott O. Lilienfeld Steven Jay Lynn Laura Namy Nancy J. Woolf Prepared by Caleb W. Lack 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 part, of any images; any rental, lease, or lending of the program. Chapter 6 LEARNİNG: HOW NURTURE CHANGES US? LECTURE PREVIEW Classical conditioning Operant conditioning Cognitive models LEARNING o o o Learning; the change in an organism’s behavior or thought as a result of experience. Habituation: the simplest & most basic form of learning. Respond less strongly over time to repeated sitimuli. Ex: the sensation of your tongue on your teeth, the feel of your clothing against your skin, the chair you sit o Adaptive ! (Only stimuli that are safe) o Sensitization: responding to stimuli more strongly over time (when a stimulus is dangerous, irritating or both) Ex: tick-tack of the clock, or studying while someone whispering. CLASSICAL CONDITIONING o Large amounts of learning occur though association; associating one thing with the other. Ex: appearance of apple the taste of apple o Conditioning; the process of attaining knowledge by forming associations. Ex: mother’s voice & face o Behaviorists; simple associations complex ideas CLASSICAL CONDITIONING o Studies of Ivan Pavlov (Russian physiologist & Nobel Prize winner) o Famous for work on digestion of dogs. o Pavlov; dogs’ salivary responses to meat power o Dogs also salivated to research assistants who brought the meat power. o Meat power + research assistant (previosly neutral stimulus) o Anticipation of the meat powder & responding to the stimuli that signaled its arrival. CLASSICAL CONDITIONING o Classical conditioning; learning in which organisms come to respond to a previously neutral stimulus that had been paired with another stimulus that elicits an automatic response. o Five primary components; Neutral stimulus (NS)- stimulus that does not elicit a particular response; presence of research assistant Unconditioned stimulus (UCS)- a stimulus that elicits an automatic response or reflex; meat powder Unconditioned response (UCR)- the automatic response or reflex; salvation of the dog Conditioned stimulus (CS)- the stimulus that was previously neutral, but comes to elicit a CR response as a result of its association with the UCS; research assistant Conditioned response (CR)- The automatic response or reflex that was previously asscoiated with UCS (meat powder) & now comes to be elicited with the CS (research assistant); salvation of the dog.- CLASSICAL CONDITIONING Classical Conditioning Steps 1. • • 2. 3. • o Start with a neutral stimulus, which does not elicit a particular response Meat powder (UCS) salivation (UCR) Metronome (NS) Pair the NS repeatedly with the unconditioned stimulus, which elicits an unconditioned response Now, the NS becomes a conditioned stimulus, eliciting a conditioned response Metronome (NS-CS) salivation (UCR-CR) The organism reacts the same way to the previously NS as it did to the UCS CLASSICAL CONDITIONING o Principles of Classical Conditioning; Acquisition Extinction Spontenous Recovery Stimulus Generalization Stimulus Discrimination CLASSICAL CONDITIONING Acquisition: the phase during which a CR is established. o Learning and acquiring the CR, gradually . o As the CS & UCS are paired again & again CR increases in strength. o The closer the time CS & UCS the (a half sec. delay) Longer delays the speed of learning & the strength of the response . Extinction: gradual reduction / elimination of the CR after the CS is presented repeatedly without the UCS o Metronome without meat powder (repeatedly) no salivating. o Not forgetting, learning! (a new response ) (absence of salivation writes over previous CR) o The extinguished CR does not vanish completely (overshadowed) 12 CLASSICAL CONDITIONING Spontenous Recovery: phenomenon of a seemingly extinct CR reappears (often in a weaker form) if it is presented UCS again. o Only CS (metronome) repeatedly CR extinguished (the salvation of the dog). o 2 hours later; CS again the CR returned (the animal did not forget the CR just supressed it) o Can explain why people who have overcome their phobias, experience areappearance of the symptoms of phobia when returned to the environment that caused phobia Stimulus Generalization: occurs when similar CSs elicit a CR. o Both metronome & also sounds similar to it dogs salivated o More similar the stronger the CR (adaptive; you can transfer what you have learned to new things. 14 CLASSICAL CONDITIONING Stimulus Discrimination: it occurs when a less pronounced CR emerges to CS different from the original CS. Ex: Enjoying scary movies- (discriminate btw. a televised stimulus & the real version) o Also adaptive; allows to distinguish among stimuli that share similarities but that differ in important ways. o Higher Order Conditioning: Process where organisms develop classically conditioned responses to new CSs associated with the original CS. o Developing CR to CSs that later become associated with the original CS. Ex: Metronome salvation Metronome + Circle salvation Circle o Becomes weaker the farther from the original CS 15 APPLICATIONS OF CLASSICAL CONDITIONING o Commercials; Advertisers repeatedly pair their products with stimuli that elicit positive emotions. APPLICATIONS OF CLASSICAL CONDITIONING o Helps to explain how and why we acquire some fears & phobias Studies of Watson & Rayner (1920); Little Albert; (9 month old infant) Little Albert fond of rat (fury creatures) Rat + sound of a gong (repeatedly) cries Rat cries. Stimulus generalization (rabbit, dog, a furry coat & Santa Claus Mask) http://www.youtube.com/watch?v=9hBfnXACsOI o Can also help to treat phobias • Study of Jones (1924); Little Peter; 3-year old baby w/ phobia of rabbits. white rabbit + favorite candy (repeatedly) white rabbit pleasure OPERANT CONDITIONING o o o Learning controlled by the consequences (both positive & negative) of behavior Beh. is shaped by what comes after it. The organism gets stg. (reward or punishment) bec. of its response. o Instrumental conditioning; organism’s response serve as a instrumental function. o Operant conditioning: the animal operates on the environment to get what it wants. DIFFERENCE BETWEEN OC & CC CLASSICAL CONDITIONING OPERANT CONDITIONING Target behavior is… Elicited automatically Emitted voluntarily Reward is… Provided unconditionally Contingent on behavior Behavior depends primarily on… Autonomic nervous system Skeletal muscles OPERANT CONDITIONING o E.L. Thorndike; If a response, in the presence of a stimulus, is followed by a satisfying state of affairs, the bond btw. the stimulus & respond will be strenghtened(principle of the law of effect) o o o o If we’re rewarded for a response to a stimulus, we’re more like to repeat that response. Association btw. stimulus & response (S-R), w/ the reward Cats in puzzle boxes. Thorndike found that the cat’s time to escape from the box diminished gradually after 60 trials. (trial-error) OPERANT CONDITIONING &REINFORCEMENT o B.F. Skinner- followed Watson & Thorndike’s work on behavior. o Skinner box ; a bar that delivers food when pressed, a food dispenser & a light that signals when the reward is forthcoming. o o o Reinforcement Punishment Discriminative Stimulus OPERANT CONDİTİONING &REINFORCEMENT o o o Reinforcements; are outcomes that strengthen the probability of a response Positive reinforcement involves giving a stimulus (Ex: giving a child a kiss when he picks up his toys) Negative reinforcement involves taking away a stimulus (Ex: ending a child’s time out for bad beh. once she becomes silent. Punishment; any outcome that weakens the probability of a response. Positive Punishment: administering a stimulus that the organism wishes to avoid (e.g. Spanking the child for his bad beh.) Negative Punishment: removal of stimulus that the organism wishes to experience (e.g. Don’t letting the child going out for his bad beh. ) Disciplinary actions; punishments only if they decrease the chance of the behavior (actions might appear punishments but are actually reinforcement) PROCEDURE EFFECT EXAMPLE Positive Reinforcement Presenting a stimulus Increases target behavior Gold star on homework makes student feel special Negative Reinforcement Removing a stimulus Increases target behavior cleaning up your mess in the kitchen in order to avoid getting in a fight with your roommate. Positive Punishment Presenting a stimulus Decreases target behavior Scolding a dog to stop chewing on shoes Negative Punishment Removing a stimulus Decreases target behavior Taking away a toy to stop a child from throwing at television OPERANT CONDITIONING &REINFORCEMENT Before heading out for a day at the beach, you slather on sunscreen in order to avoid getting sunburned. Giving a child a compliment or candy for a job well done Spanking a child for inappropriate behavior Child has a toy taken away for fighting with his sister Leaving a movie theater if the movie is bad Dolphin gets a fish for doing a trick Dolphin trainer walks away with fish bucket when the dolphin gets aggressive Rushing home in the winter to get out of the cold Swatting a dog with a newspaper for peeing on the carpet Taking aspirin to relieve headache Smoking in order to reduce a negative emotional state Watching your favorite TV show after doing all your homework One person in a relationship stops talking to the other in response to a behavior Women yelling her room-mate for leaving dirty clothes scattered OPERANT CONDITIONING o Discriminative Stimulus: stimulus that signals the presence of reinforcement. Ex: A friend’s waving at us. (signals that our friend wants to chat with us) o o Acquisation, extinction, spontaneous recovery, stimulus generalization & stimulus discrimination. Extinction: stop delivering reinforcers beh. declines/ disappears. o Extinction burst: (after withdrawing the reinforcer) the undesired beh. first increases then it diminishes. o Ex: screaming child parents give a toy (reinforcement) screaming child parents ignore screaming (extinction) child will cry more tries harder to get reinforced (extinction burst) o OPERANT CONDITIONING o Stimulus Discrimination: Watanabe et al. (1995) used food reinforcement to train pigeons to distinguish the paintings by Monet from those of Picasso. The pigeons learned to tell the difference btw. two types of stimuli. o Stimulus Generalization: Pigeots distiguished paintings by impressionist artists whose style is similar to Monet’s (e.g. Renoir), from paintings by cubist artists whose style is similar to Picasso (e.g. Braque). SCHEDULES OF REINFORCEMENT o o Skinner (1938) animals’ beh.s differ depending on the schedule of reinforcement. Schedule of Reinforcement; pattern of delivering reinforcers. Continuous Reinforcement: the simplest pattern the beh. is reinforced everytime it occurs. Partial Reinforcement: when the responses are reinforced only some of the time o Continous reinforcement learning more quickly Partial reinforcement more resistant to extinction. SCHEDULES OF REINFORCEMENT o The schedules of reinforcement vary along two dimensions; o Consistency of administering reinforcement; Fixed or variable: providing reinforcement on a regular (fixed) basis or providing reinforcement on an irregular basis. o The basis of administering reinforcement Ratio or interval: ratio schedules reinforcement based on the number of responses interval schedules reinforcement based on the amount of time elapsed SCHEDULES OF REINFORCEMENT o Four major type of schedules of reinforcement; Fixed Ratio (FR) – the reinforcement is provided after a regular number of responses. (E.g.; the rat gets a chocolate bar to after it presses the lever 15 times.) Variable Ratio (VR) – the reinforcement is provided after specific number of responses on average, but the precise number of responses during any given period varies randomly. ( E.g.; A pigeon receives bird feed after 6, 12, 1, 21 pecks; aver. ratio = 10.) Fixed Interval (FI) – the reinforcement is provided after specific amount of time has passed. ( E.g;. The worker gets paid every Friday for the work she has done): Variable Interval (VI)- the reinforcement is provided after an average time interval, with the actual time interval varies randomly. (E.g.; the dog reinforced after a 7,20,4’,1 minute interval, aver. Int. = 8 minutes.) Schedules of Reinforcement Each schedule yields distinctive response patterns Variable ratio (VR) yield the highest rate of responding. (Gambler’s case) APPLICATIONS OF OPERANT CONDİTİONİNG o Operant Conditioning is used in; Animal training: shaping by successive approximations & chaining. Shaping reinforce behaviors that are not exactly the target beh.s but closer versions of it, then gradually fading our reinforcement for notexactly right beh.s over time. Chaining animal trainers link a number of interrelated beh.s to form longer series. (Skinner taught pigeons to play Ping-Pong with this technique). Overcoming procrastination via the Premack principle Positively reinforcing a less frequently performed beh. with more frequently performed beh. Reinforce yourself with higher frequency beh.s (e.g.watching tv) only after you completed your homework. APPLICATIONS OF OPERANT CONDİTİONİNG o o Operant Conditioning is used in; Using token economies in clinical settings to shape desired behaviors Secondary reinforcers (e.g. tokens, chips, points) given to patients exhibiting desirable beh.s., so patients can obtain primary reinforcers (e.g. food, drink). Applied behavior analysis (ABA) for language deficits in autism Mental health professionals offer food & other primary reinforcers to ind.s with autism as they reach progressively closer approximations to certain words & complete sentences. better language & intellectual skills than control groups of children with autism COGNITIVE MODELS OF LEARNING o Early behaviorists (e.g. Skinner )did not believe that thinking played much of a role in learning o Skinner; cognitive psychology unobservable & meaningless concepts ( e.g.mind) to explain beh. o Role for cognitions; Stimulus-response (S-R) Stimulus-Organism-Response (S-O-R) o o The way an organism responds to a stimulus depends on what the stimulus means to it OC depend on thinking OBSERVATIONAL LEARNING o Observational learning; learning by watching others (or models; e.g. parents, teachers) o Don’t have to engage in trial and error to learn how to do something new (adaptive!) E.g. It would be wise to have a parachute on before jumping out of a plane). o Bandura (1960); showed that children can learn to act aggresively by watching agressive role models. OBSERVATIONAL LEARNING o Bobo-Doll Experiment (Bandura et al.1961); Children randomly assigned video an adult model playing w/ the Bobo-doll, the adult model punching the bobo-doll. exposure to the agressive model triggered more agression http://www.youtube.com/watch?v=Pr0OTCVtHbU o o Many types of research has examined the impact of violent media on behavior. Media violence impacts real-world aggression MIRROR NEURONS & OBSERVATIONAL LEARNING o Observational learning activates mirror neurons. o o o Mirror neurons; a neuron that fires both when an animal acts and when the animal observes the same action performed by another. E.g. when a monkey watches another monkey perform an action/ (e.g. reaching an object), group of neurons becomes activated. These are the same cells that would have become active had the monkey performed the same movement. PET scan; a similar mirror neuron system in humans identified. (Gallese & Goldman, 1998). o Observational learning & empathy
