Unit 6 - Learning: Unit 6 - Learning University High School AP Psychology 2007-08


Learning Overview: Learning Overview learning: a relatively permanent change in behavior that results from experience at the heart of adaptability We learn largely by association: mentally pairing events together when they occur together conditioning: the process of learning associations between events classical conditioning: events are 2 stimuli operant conditioning: events are response and its consequences We also learn by watching others and learning from their experiences (observational learning)


Classical Conditioning: Classical Conditioning a type of learning that occurs when a neutral stimulus becomes paired (associated) with a stimulus that causes a reflexive behavior and, in time, is sufficient to produce that behavior by itself most famous example of classical conditioning: Pavlov’s dogs


Ivan Pavlov (1849-1936): Ivan Pavlov (1849-1936) Russian physiologist, Nobel Prize-winning work on digestive processes noticed that dogs salivated when food was put in mouths, but also (after repeated feedings) at sight of food dish, sight of person who brought food, etc. turned attention to studying learning


Before Conditioning: Before Conditioning conditioned = learned, unconditioned = unlearned unconditioned stimulus (US): a stimulus that automatically elicits a response (food) unconditioned response (UR): the automatic, reflexive response to the US (salivation)


Before Conditioning: Before Conditioning before conditioning, a neutral stimulus (e.g. a tone from a tuning fork) does not elicit response during conditioning, US (food) is presented with the neutral stimulus (tone)


After Conditioning: After Conditioning conditioned stimulus (CS): an originally neutral stimulus that acquires significance through repeated pairings with the unconditioned stimulus (tone) conditioned response (CR): the learned response to a previously neutral (but now conditioned) stimulus (salivation)


Classical Conditioning: Classical Conditioning after initial studies, Pavlov & colleagues turned to studying parameters of classical conditioning acquisition: initial learning of the association between a neutral stimulus (tone) and a US (food) level of acquisition depends largely on the timing of stimuli presentation


Forward Conditioning: Forward Conditioning procedure in which the CS (tone) begins before the US (food) is presented used in original Pavlov studies, 2 types 1. delayed conditioning: CS occurs both before and during US 2. trace conditioning: CS ends before US begins both work well (trace effective if there is a very short time between CS and US; 0.5 sec?) CS _____________________________________ US _____________________________________ CS _____________________________________ US _____________________________________


Non-Forward Conditioning: Non-Forward Conditioning backward conditioning: conditioning procedure in which the US (food) is presented before the CS (tone) simultaneous conditioning: conditioning procedure in which the US (food) and CS (tone) are presented at the same time CS _____________________________________ US _____________________________________ CS _____________________________________ US _____________________________________


Forward vs. Non-Forward: Forward vs. Non-Forward Forward conditioning (delayed, trace) works well. easy acquisition of association by both humans and other animals CS before US: predictive value, CS informative about upcoming important future events (US) Non-forward conditioning (backward, simultaneous) much less effective. CS after US: no predictive value Learning is adaptive in large part because it tells us what to expect and prepare for in the future. Non-forward conditioning does not provide this advantage.


Extinction & Spontaneous Recovery: Extinction & Spontaneous Recovery extinction: the process by which a CR (salivation) comes to be eliminated through repeated presentations of the CS (tone) without the presence of the US (food) CS no longer a reliable predictor of US extinction not forgetting association, but rather layering new learning on top of old


Extinction & Spontaneous Recovery: Extinction & Spontaneous Recovery spontaneous recovery: the reappearance, after a pause, of an extinguished conditioned response e.g. after extinction and several hours, Pavlov’s dogs began to salivate to the tone again responses often not as strong as during initial acquisition period


Reacquisition: Reacquisition once classical conditioning has occurred, connection between CS (tone) and US (food) never completely disappears reacquiring association happens much faster than initial association


Generalization & Discrimination: Generalization & Discrimination stimulus generalization: tendency for the CR (salivation) to be elicited by neutral stimuli that are similar to, but not identical to, the CS (tone) e.g. Pavlov’s dogs began to salivate when a slightly different tone sounded very adaptive


Generalization & Discrimination: Generalization & Discrimination generalization occurs on a gradient; the more closely the new stimulus resembles the original CS, the stronger the response stimulus discrimination: the ability to distinguish among similar stimuli and to respond only to actual conditioned stimuli like generalization, adaptive value of stimulus discrimination


The Behaviorist Zeitgeist: The Behaviorist Zeitgeist Pavlov: psychology a product of learned associations inspired John B. Watson, founder of behaviorism: school of psychology that focused exclusively on observable behavior, denied importance/existence of “mentalistic” concepts (e.g. consciousness, emotion, etc.) More recent research suggests important roles of cognitive and biological constraints on classical conditioning.


Cognition & Classical Conditioning: Cognition & Classical Conditioning Forward conditioning effective; creates an expectancy about what will happen next Kamin (1969): conditioned rats by pairing tone with brief shock, developed fear response to tone light introduced as 2nd CS, no fear response to light (no additional information) Expectations, visualizations influence effectiveness of conditioning


Acquisition of Attitudes: Acquisition of Attitudes attitude: an overall evaluation of an object, ranging from positive to negative can be a result of associations Olson & Fazio (2001): classical conditioning of people’s attitudes toward Pokemon characters participants shown stream of words, images, Pokemon characters; had to respond to target character by pressing button


Olson & Fazio (2001) cont.: Olson & Fazio (2001) cont. two other Pokemon characters appeared, one with positive words and images, the other with negative after task, asked to evaluate all Pokemon characters shown preference for those associated with positive stimuli (attitudes as a result of conditioning!) awesome awful


Acquisition of Emotions: Acquisition of Emotions conditioned emotional response: an emotional response elicited by a previously neutral stimulus can lead to phobias: irrational, persistent fears of a specific object or situation Watson & Rayner, 1920: case of “Little Albert”


Little Albert: Little Albert 11 month old infant allowed to play with white rat, showed no fear of rat, but did fear loud noises subsequent trials: Watson would loudly strike metal bar with a hammer behind Albert’s head whenever Albert approached the rat


Little Albert: Little Albert soon developed a phobia of rats; began crying and withdrawing when rat was presented “He fell over on his left side, raised himself, and began to crawl away so rapidly that he was caught with difficulty before reaching the edge of the table.” case of conditioning fear loud noise: US white rat: originally neutral stimulus, now CS crying: UR for noise, CR for rat


Little Albert: Little Albert generalized fear to other similar objects furry dog, rabbit, sealskin coat, Watson dressed as Santa Claus (with white cottonball beard) did not generalize to dissimilar objects (e.g. toys) Albert adopted during experiment, reconditioning never happened No one knows what happened to Albert...


Biology & Conditioning: Biology & Conditioning at least 3 separate brain processes involved in classical conditioning 1. registering the stimulus sensory strip in parietal lobe, auditory & visual cortices, etc. 2. production of response motor cortex, amygdala for fear response, etc. 3. communication between two sets of neurons learning leads to creation, strengthening of neural connections connections remain even after extinction; why it is so easy to reacquire associations


Biology & Conditioning: Biology & Conditioning Pavlov and others: basic laws of learning similar for all animals, including humans any natural response can be conditioned to any neutral stimulus with equal effectiveness Not true! biological preparedness: a built-in readiness for certain conditioned stimuli to elicit certain conditioned responses such that less learning is necessary to produce conditioning


Biological Preparedness, cont.: Biological Preparedness, cont. easier to condition fear responses to some stimuli than others (Ohman et al., 1976) US: electric shock CS: pictures measured sweaty palms as an indicator of fear sweaty palms easier to condition in response to snakes, spiders, dark rooms, etc. than to flowers, mushrooms, etc. (adaptive function)


Another Type of Preparedness: Another Type of Preparedness food/taste aversion: a classically conditioned avoidance of a certain food or taste typically occurs after a single CS-US pairing US: nausea-inducing agent (e.g. salmonella) CS: sight or smell of food (previously neutral or even positive) UR/CR: nausea, vomiting, other sickness


Discovery of Taste Aversion: Discovery of Taste Aversion Garcia & Koelling (1966): studying effects of radiation on rats rats drank less water from bottles in radiation chamber (plastic bottles) than those in home cage (glass bottles) due to association between taste of water in plastic bottles and feeling ill from radiation?


Garcia & Koelling (1966): Garcia & Koelling (1966) rats given water sweetened with saccharine IV: drinking water followed by no radiation/mild radiation/strong radiation subsequently given choice to drink sweetened water or regular tap water DV: how much of each type of water consumed by rats


Garcia & Koelling (1966): Garcia & Koelling (1966)


Garcia & Koelling (1966): Garcia & Koelling (1966) new discoveries about classical conditioning principles: taste aversion can occur with a single pairing of flavor and illness occurs even if illness happens several hours after exposure to flavor (long-delay learning) adaptive function; allows animal to avoid poisonous foods in the future greatest aversion when radiation occurs 6 hours after drinking sweet water; less aversion at 12 hours; almost no aversion at 24 hours


Applications of Taste Aversion: Applications of Taste Aversion treating alcoholism, using the drug Antabuse causes nausea and violent vomiting when combined with alcohol attempts to create a taste aversion to alcohol Problem: alcoholics tend to stop taking Antabuse so they can drink again but when used properly, Antabuse does reduce total amount of alcohol consumed (Brewer et al., 2000; Chick et al., 1992)


Applications of Taste Aversion: Applications of Taste Aversion humane methods of controlling predators, agricultural pests? coyotes & wolves ate sheep carcasses laced with nausea-inducing poison; developed aversion to sheep meat (Gustavson et al., 1974, 1976) wolves penned with sheep later seemed to fear it! similar results with baboons in African gardens, raccoons attacking chickens, ravens & crows feeding on raven eggs


Other Applications of Classical Conditioning: Other Applications of Classical Conditioning 1. understanding physical functioning of body, responses to medications e.g. conditioning the immune system Ader & Cohen (1975): attempted to study taste aversion in rats: pair saccharine water with cyclophosphomide (drug given during organ-transplant surgery to suppress immune system, side effect = nausea) wanted to know how long aversion to saccharine water would last after injections stopped, but rats continued to drink water


Ader & Cohen (1975) cont.: Ader & Cohen (1975) cont. from day 45 on: rats began dying rats in previous studies (similar, but used different drug) hadn’t died… what’s happening? taste of sweetened water induces immune system suppression (even in the absence of immune-suppressing drug!) implications: placebo effect in animals other than humans immune system can also be boosted via conditioning rats with lupus (a disease where immune system attacks otherwise healthy organs) who have saccharine/immune-suppression drug association  decreased symptoms after drinking saccharine water (Ader & Cohen, 1982)


Other Applications of Classical Conditioning: another medical example: chemotherapy nausea, vomiting = common side effects of chemotherapy anticipatory nausea: classically conditioned response to chemotherapy, triggered by previously neutral CS US: chemotherapy CS: trip to hospital, thinking about hospital, nurse who administers chemotherapy, etc. UR/CR: nausea also often develop aversion to foods eaten before chemotherapy session (Bernstein, 1978,1991; Carrell et al., 1986) one explanation for lack of appetite common among chemotherapy patients Other Applications of Classical Conditioning


Other Applications of Classical Conditioning: Other Applications of Classical Conditioning yet another medical example: anorexia nervosa disorder characterized by severe and chronic weight loss correlated with digestive disorders; may increase likelihood of learning taste aversions


Other Applications of Classical Conditioning: 2. drug addictions and overdoses user who typically takes drug in a specific setting develops conditioned response to that place (Siegel, 1988; Siegel et al., 2000) CR: body compensates for expected influx of drug, to counteract or dampen effect of drug taking drug in new setting does not elicit CR can lead to overdose: person expects to be able to handle dose, but effect is greater in new environment because body does not compensate in advance Other Applications of Classical Conditioning


Other Applications of Classical Conditioning: 3. advertising many ads aim for association between product and positive US viewing political slogans (CS) while eating food (US) leads to more positive evaluations of slogans (Razran, 1940) Other Applications of Classical Conditioning


Other Applications of Classical Conditioning: 4. therapy techniques systematic desensitization: a behavior therapy technique that teaches people to be relaxed in the presence of a feared object or situation often used to treat phobias inability to feel relaxed and anxious at same time; conditioning relaxed feelings with thoughts of frightening stimulus/situation Other Applications of Classical Conditioning


Other Applications of Classical Conditioning: systematic desensitization works by gradually exposing person to feared stimulus Other Applications of Classical Conditioning


Operant Conditioning: Operant Conditioning the type of learning in which a specific behavior becomes associated with its consequences reinforcers increase behavior, punishments decrease behavior


Classical vs. Operant Conditioning: Classical vs. Operant Conditioning Classical associations created between external stimuli, typically out of organism’s control (passive) relevant behavior is an automatic, reflexive response Operant associations created between organism’s behavior & its consequences (active) relevant behavior is voluntary, operating on environment


Thorndike’s Puzzle Box: Thorndike’s Puzzle Box Edward Thorndike (1874-1949): created a puzzle box: cage with latched door that could only be opened by pressing lever inside cats became quicker and quicker to press lever once they figured it out Law of Effect: rewarded behaviors are more likely to be repeated


B.F. Skinner (1904-1990): B.F. Skinner (1904-1990) most influential (and controversial?) psychologist of the behaviorist movement developed principles behind operant conditioning through use of the Skinner Box (operant chamber)


Skinner Box: Skinner Box


How Does Operant Conditioning Work?: How Does Operant Conditioning Work? We often try to teach organisms to engage in behaviors that they otherwise wouldn’t. shaping: the gradual process of reinforcing an organism for behavior that gets closer and closer to the desired behavior (successive approximations)


How Does Operant Conditioning Work?: How Does Operant Conditioning Work? successive approximations reinforced (or sometimes punished), other behaviors ignored entirely e.g. training rat to push lever in Skinner box 1. turning towards lever 2. stepping towards lever 3. moving within certain distance of lever 4. touching lever 5. pressing lever


Reinforcement: Reinforcement reinforcer: an object or event that comes after a behavior that increases the likelihood of engaging in that behavior again “best” reinforcers depend on the organism, circumstances, etc.


2 Types of Reinforcement: 2 Types of Reinforcement 1. positive reinforcement: occurs when a desired reinforcer is presented after a behavior, thereby increasing the likelihood of a recurrence of that behavior most often food for animals (but also water, electrical stimulation of hypothalamus, etc.) humans: attention, approval, money, etc.


Slide53: 2. negative reinforcement: occurs when an unpleasant event or circumstance is removed following a desired behavior, thereby increasing the likelihood of a recurrence of that behavior like positive, still encourages more of the behavior Skinner box: removal of shock human examples: taking aspirin for headache, fastening seatbelt to stop dinging, drug addicts using drug to escape withdrawal symptoms 2 Types of Reinforcement


Levels of Reinforcement: Levels of Reinforcement primary reinforcer: an event or object that is inherently reinforcing by satisfying a physical need (e.g. food, water, relief from pain) secondary (conditioned) reinforcer: an event or object that is reinforcing but does not inherently satisfy a physical need (e.g. attention, praise, money, good grades, promotion) behavior modification: technique that brings about therapeutic change in behavior through secondary reinforcers


Timing of Reinforcement: Timing of Reinforcement amount of time between behavior & consequence can have dramatic effects on conditioning immediate reinforcement: reinforcement given immediately after the desired behavior is exhibited delayed reinforcement: reinforcement given some period of time after the desired behavior is exhibited more immediate = more learning


The Struggle For Self-Control: The Struggle For Self-Control general preference for immediate reinforcement humans often face need to delay gratification Mischel et al. (1989): 4 year olds given option to have small amount of candy now, large amount tomorrow choosing to wait = social competence, higher achievement in adolescence ability to delay gratification for bigger, later rewards key to life satisfaction (Logue, 1998)


The Struggle For Self-Control: self-control can be difficult to exercise; immediacy of reward often too tempting immediate pleasure of using psychoactive drugs unprotected sex driving SUVs, Hummers, etc. despite environmental concerns The Struggle For Self-Control


Some Familiar Concepts: Some Familiar Concepts some principles of classical conditioning relevant to operant conditioning too generalization: ability to generalize from a learned behavior to a similar behavior discrimination: the ability to distinguish between learned behavior and a similar behavior can be encouraged by reinforcing only the specific desired behavior discriminative stimulus: cue that tells organism whether a specific response will lead to the expected reinforcement


Some Familiar Concepts: Some Familiar Concepts extinction: after the withdrawal of reinforcement, the fading out of a learned behavior following an initial burst of the behavior spontaneous recovery: the process by which an old response reappears if there is a break after extinction


Schedules of Reinforcement: Schedules of Reinforcement early Skinnerian experiments used continuous reinforcement: reinforcing the desired behavior every time it occurs partial reinforcement: reinforcement given only intermittently continuous leads to faster initial learning... ...but partial is more resistant to extinction ...and continuous reinforcement only happens sometimes in real world


Schedules of Reinforcement: Schedules of Reinforcement 4 schedules of partial reinforcement interval schedules: reinforcement given after a specified interval of time fixed or variable ratio schedules: reinforcement given after a specified number of the desired responses fixed or variable


Interval Schedules: Interval Schedules fixed interval schedule: reinforcement given for a response emitted after a certain interval of time Skinner box example: fixed interval schedule of 10 minutes = reinforcement of first desired behavior after 10 minutes elapse frequency of behavior slows down after reinforcement, picks up right before reinforcement (scalloped pattern) human example: typical student’s study schedule


Interval Schedules: Interval Schedules variable interval schedule: reinforcement given for desired response after changing interval of time used by Skinner to counter “lazy” response pattern of fixed interval Skinner box example: intervals average 10 minutes, but individually vary (one is 13 minutes, another 7, etc.) creates slow but steady response pattern human example: pop quizzes in school (ensures students continually read, rather than cramming)


Ratio Schedules: Ratio Schedules fixed ratio schedule: reinforcement after a set number of responses Skinner box example: receiving pellet after every 10th response creates stepwise pattern of responding (high rate until reinforcement, lull, then high rate again) human example: workers paid for every 10th garment sewn, every 10th radio assembled, etc.; frequent flyer programs


Ratio Schedules: Ratio Schedules variable ratio schedule: reinforcement after a variable number of responses Skinner box example: ratio averages 1 reinforcer per 10 responses, but individual ratios vary (e.g. 1 after 13 responses, 1 after 7, etc.) human examples: slot machines, commission sales highest rate of responding, most resistant to extinction (don’t know when you’ll be reinforced)


Punishment: Punishment an unpleasant event that occurs as a consequence of a behavior decreases the likelihood of the behavior in the future not to be confused with negative reinforcement


Types of Punishment: Types of Punishment positive punishment: when behavior leads to an undesired consequence negative punishment: removal of a pleasant event or circumstance following a behavior


Punishment: Punishment needs to have 3 characteristics to be effective in shaping behavior: 1. should be swift, occur immediately after undesired behavior 2. must be consistent 3. should be sufficiently aversive without being so aversive as to cause fear or anxiety, injury, etc.


Problems With Punishment: Problems With Punishment 1. Skinner: What punishment typically teaches is how to avoid it punished behavior suppressed, not forgotten 2. physical punishment may increase aggressive behavior learning by observing others abusive parents, physically aggressive juvenile delinquents tend to come from abusive families (Strauss & Gelles, 1980; Straus & McCord, 1998) 3. may lead to fear of punisher


The Biggest Problem With Punishment: The Biggest Problem With Punishment tells you what not to do, rather than what to do punishment alone much less effective than punishment + reinforcement in general, psychologists encourage more reinforcement, less punishment parents encouraged to reframe contingencies change “If you don’t get your homework done, you can’t have the car”... ...to “You can take the car if you finish your homework”


In-Class Learning Exercise: In-Class Learning Exercise Imagine that you are a trainer at Sea World. You are trying to teach Shamu (a wild orca) to jump out of the water when you blow a whistle, while balancing a trainer on her nose. 1. How would you teach Shamu to be comfortable with human contact and approach the trainer? 2. How would you teach Shamu the trick? If using classical conditioning, what is the CS? US? CR/UR? If using operant conditioning, would you use reinforcement (+ or -)? Punishment (+ or -)? Why?


Adding Cognition to the Mix: Adding Cognition to the Mix cognitive learning: the acquisition of knowledge that often is not immediately acted on, but is stored for later use Tolman & Honzik (1930): 3 groups of rats completing a maze 1. regularly rewarded 2. no food reward 3. no food reward until day 11


Tolman & Honzik (1930) Maze: Tolman & Honzik (1930) Maze


Tolman & Honzik (1930) Results: Tolman & Honzik (1930) Results


Tolman & Honzik (1930) Results: Tolman & Honzik (1930) Results latent learning: learning that occurs without behavioral signs in wandering, rats created a cognitive map of the maze (didn’t use cognitive map until motivated by reinforcement) Bottom line: mental processes such as expectations, memory, perception, etc. involved in learning


Another Example of Cognition in Learning: Another Example of Cognition in Learning insight learning: when an organism suddenly grasps the meaning of something and incorporates that new knowledge into old knowledge the “aha” moment


Insight Learning: Insight Learning Wolfgang Kohler (1925): studied insight learning in chimpanzees chimps needed to think creatively, use tools, etc. to retrieve out-of-reach food consistently demonstrated “aha moment” after initial frustration


Insight Learning: Insight Learning Wolfgang Kohler (1925): studied insight learning in chimpanzees chimps needed to think creatively, use tools, etc. to retrieve out-of-reach food consistently demonstrated “aha moment” after initial frustration


Observational Learning: Observational Learning social learning theory: learning occurs in a social context, and is as much a product of watching others as it is of making associations modeling: the process of observing and imitating a specific behavior Bandura et al. (1961): Bobo doll study


Observational Learning: Observational Learning Bobo doll study: part of human understanding of how to interact with environment comes from watching others same with rats, pigeons, crows, gorillas, & monkeys de Waal & Johanowicz (1993): stumptail macaque monkeys make friendly contact after fight to reconcile rhesus macaque monkeys do not, unless raised with older stumptails


Mirror Neurons: Mirror Neurons neurons that fire when performing certain actions, or when observing someone else engaging in those actions heaviest concentration in frontal lobe, near motor cortex first discovered in macaque monkeys with tasks like grasping, holding, & tearing (Rizzolatti et al., 2002)


Mirror Neurons: Mirror Neurons many possible functions of mirror neuron system? 1. understanding others’ intentions 2. theory of mind: the ability to infer another’s mental state 3. empathy mirror neurons for emotional experiences (Wicker et al., 2003; Singer et al., 2004) stronger activation of mirror neuron system for women (Cheng et al., 2006) 4. language development? 5. connections to autism?


TV & Observational Learning: TV & Observational Learning pervasiveness of TV 9 in 10 teens in US report watching TV daily (Gallup, 2002) avg. American to live to 75 = 9 years of watching TV (Kubey & Csikszentmihalyi, 2002) 2/3 of US homes have 3+ TVs Does observational learning occur while watching TV?


Violence & TV: Violence & TV average US child has seen 8,000 murders and 100,000 other acts of violence on TV before finishing elementary school as of Donnerstein (1997): 6 in 10 programs contained violence 74% of violence went unpunished 58% did not show victim’s pain 50% involved “justified” violence nearly 50% involved attractive perpetrator


Violence & TV: Violence & TV


Violence & TV: Violence & TV exposure to media violence among elementary school students positively correlated with getting in fights (Gentile et al., 2004) childhood viewing of TV violence correlated with aggression & crime as teenagers (Eron, 1987) US & Canadian homicide rates doubled between 1957-1974 (spread of TV) areas that got TV late had a late homicide spike


Violence & Video Games: Violence & Video Games like TV, strong ties between video game & real life violence playing Mortal Kombat leads to rising levels of physiological arousal and hostility in men (Ballard & Wiest, 1998)


Violence & Video Games: Violence & Video Games increased amounts of video game violence = increased self-reported violence (Anderson & Dill, 2000) playing violent video game (as compared to Myst) leads to increased interpersonal hostility, increased likelihood of blasting fellow student with painful noise


Violence & Media: Violence & Media two major psychological effects of media violence 1. imitation (as young as 14 months!) after watching Power Rangers, kids exhibit sevenfold increase in violent play imitate exact actions, words 2. desensitization more indifference to future events of violence (real or televised) (Rule & Ferguson, 1986) males watched sexually violent movies for 3 consecutive evenings (Mullin & Linz, 1995) less bothered by watching rapes less sympathy for domestic violence victims, rated victims’ injuries as less severe


Learning Summary: Learning Summary Learning allows us to adapt to the world and live our lives in safer, more productive, and happier ways. Can learn in a variety of ways: associations between events in the world (classical conditioning) consequences of our behaviors (operant conditioning) watching the experiences of others (observational learning) and just using our big brain! (cognitive, insight learning)