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Learning What counts as learning? A child speaking a second language with more fluency every day A parrot repeats a new sentence A dog who waits by the door for you every time it hears the school bus A computer that has been programmed with a new rule for solving problems You think about a cool new fact you just heard in AP Psychology Learning: a relatively permanent change in behavior due to experience We learn most things by association Animals learn to associate one stimulus with another (classical conditioning) Ex: Jaws theme song signals shark attack Ex: sea slugs can learn that water squirts signal electric shock Complex animals associate their own behavior with results (operant conditioning) Ex: dogs associate begging with being fed Ivan Pavlov Behaviorist Studied digestion Taught dogs to salivate at the sound of a buzzer by associating the buzzer with blowing meat powder into the dog’s mouth Classical Conditioning Before conditioning: Present unconditioned stimulus (US, aka UCS) Give the dog food Result: dog will salivate unconditioned response (UR, aka UCR) During conditioning: Pair a neutral stimulus with the US Give the dog food and sound a tone Result: dog will salivate because of the food After conditioning: Present conditioned stimulus (CS) - tone Result: dog will salivate because of the tone alone (conditioned response or CR) Some tricks In any situation, replace the word “conditioned” with the word “learned” ‘Conditioned response’ becomes ‘learned response’ The UR and the CR are usually the same - what changes is the stimulus Dog salivates for food and tone Adaptive value Natural examples of conditioning prepare us for events Lightening warns about thunder Smell of cooking alerts us to dinner Helps animals avoid danger, find food, and be ready to reproduce Conditioning is stronger when we are aware of it Acquisition Learning a new stimulus-response pair for the first time Timing is important - ideally the CS is presented first with a very slight delay or overlap of the US CS used to predict US Extinction If the CS is presented repeatedly without the US, the CR will eventually stop happening Dogs will unlearn that a tone signals food if food never shows up after the tone Spontaneous Recovery After not being exposed to the CS for a while, CR may occur the next time CS does (even after extinction) Generalization Animals may respond to stimuli that are similar to the CS (ex: tone of different pitch) May be adaptive – ex dog abused by a man fears all men Discrimination Animals can also learn to distinguish between two similar stimuli if the US is only presented after one of them Also adaptive – small differences in stimuli can mean big differences in safety Cognitive processes? Early behaviorists ignored all cognition Modern research shows rats can learn the reliability of the CS for predicting the US Rats distinguish between two CS and only respond to the more reliable one Dogs (and people) can develop learned helplessness: if they are repeatedly put in situations they have no control over, they will not react when they do have control Awareness of conditioning may diminish or enhance its usefulness in therapy If you know alcohol is spiked, you won’t generalize the result to all alcohol If you know positive associations are helpful, you may make stronger ones Biological effects Conditioning is faster, stronger, and longer-lasting if it is relevant to your survival Taste aversions Trauma “a burnt child dreads the fire” “once bitten, twice shy” Conditioned stimuli with a natural connection to the unconditioned stimuli they predict Experiment to Know John B. Watson used classical conditioning on baby “Little Albert” Used a frightening noise as the US and a rat as the CS. Albert’s UR and CR was fear. Albert generalized the CR to furry things like rabbits, dogs, and fur coats B. F. Skinner Built the operant chamber (aka Skinner box) Trained pigeons to guide missiles in WWII Researched the principles of behavior control based on law of effect: Rewarded behavior is likely to happen again Figure 6.12 A Skinner box Inside the box, the rat presses a bar for a food reward. Outside, a measuring device (not shown here) records the animal’s accumulated responses. © 2010 by Worth Publishers Operant Conditioning Behavior that operates on the environment leads to either reinforcement or punishment Animals learn to associate their behavior with its result Shaping Shaping is used to train animals to do complex behaviors 1. Start with what the animal can do 2. Reward it for doing something close to what you want 3. Require it to get closer and closer to the desired behavior before rewarding it Give an example of shaping. Shaping cont. Shaping also helps researchers discover what animals can perceive, and even some mental processes (forming concepts) Ex: pigeons have been trained to distinguish between human faces, flowers, and cars, and can sort new pictures into the right category Reinforcers Anything that strengthens the behavior it follows Positive reinforcement adds (+) a pleasant stimulus Negative reinforcement removes (-) an unpleasant stimulus Ex:Doing your chores earns allowance Ex: hitting the snooze button stops your alarm clock NEGATIVE REINFORCEMENT IS NOT PUNISHMENT (it actually removes punishment) Primary and Secondary Reinforcers Primary reinforcers are unlearned Ex: chocolate is delicious Secondary or conditioned reinforcers are associated with primary reinforcers Ex: money can be used to buy chocolate Immediate reinforcement is necessary for rats Humans can choose delayed reinforcement working today to get paid tomorrow Children who demonstrate the ability to wait for delayed reinforcement become high-achieving adults Reinforcement Schedules Describe when and how often behavior is reinforced Continuous: behavior is reinforced every time Learning happens quickly Extinction also happens quickly Not common in the real world Partial or intermittent: behavior is sometimes reinforced Learning happens more slowly Extinction is very difficult Example? Intermittent Reinforcement Schedules Fixed-ratio schedule: behavior is reinforced after a set number of times Variable-ratio: behavior is reinforced after an unpredictable number of times Ex: slot machines Fixed-interval: behavior is reinforced after a set amount of time EX: Loyal customer card - buy 10, get the 11th free Checking the mail every day around delivery time Variable-interval: behavior is reinforced after an unpredictable amount of time Ex: checking email Figure 6.13 Intermittent reinforcement schedules Skinner’s laboratory pigeons produced these response patterns to each of four reinforcement schedules. (Reinforcers are indicated by diagonal marks.) For people, as for pigeons, reinforcement linked to number of responses (a ratio schedule) produces a higher response rate than reinforcement linked to amount of time elapsed (an interval schedule). But the predictability of the reward also matters. An unpredictable (variable) schedule produces more consistent responding than does a predictable (fixed) schedule. © 2010 by Worth Publishers Punishment Punishment decreases the frequency of a behavior Can add an unwanted stimulus (speeding tickets) or take away something desired (freedom while in jail) The most effective punishment is swift and certain Physical Punishment Physically punished behavior is temporarily suppressed, not forgotten Physical punishment may teach discrimination instead of stopping a behavior Physical punishment can teach fear of the person and place, not just the behavior Physical punishment models aggression as a solution for problems Physical punishment works best as an occasional back-up that is combined with reasoning Reinforcement gets more permanent results and makes people happier Cognition and Operant Conditioning Latent learning occurs in rats and people - learn by observing or practicing, but don’t demonstrate learning until later when it is needed Insight is when learning seems to occur spontaneously Intrinsic vs Extrinsic motivation Intrinsic motivation comes from within (you do something because you enjoy it) Extrinsic is external (you do it because you get paid, or because you have to) Offering extrinsic motivation for something people enjoy can cause them to enjoy it less Biology and Operant Conditioning Animals are better at learning things that are naturally adaptive Animals may experience instinctive drift away from the trained behavior and toward their natural behavior Observational Learning AKA social learning - learning through observation and imitation (modeling) Works for complex creatures (most mamals and some birds) Mirror Neurons Accidentaly discovered in 1991 Found in frontal lobe Fire when acting or watching others act May be useful for empathy, imitation, and infering the mental state of others Infants and children imitate the behavior of an adult At 14 months children imitate what they see on TV Mirror neurons may explain our reactions to movies, books, and contagious yawns An Experiment to Know Albert Bandura “Bobo Doll” experiment Experimental group of children watched an adult beat up an inflatable doll, the control group did not Experimental group mimicked aggressive behaviors and invented new ones Control exhibited little to no aggressive behavior http://www.youtube.com/watch?v=YclZBhn40hU We more readily imitate someone if They are similar to us They are rewarded for their behavior Prosocial Effects of Modeling Positive role models can increase prosocial behavior Models are most effective when their words and actions are consistent Examples read with children to encourage independent reading Christians who rescued Jews in the Holocaust were more likely to have had a parent with strong morals Antisocial Effects of Modeling Abusive or violent behavior can also be learned by observation, in person or on TV Many studies demonstrate a postive correlation between viewing violence on TV or in video games and aggressive behavior From imitation (like Bobo Doll) From desensitization (minimizes empathy for victims)