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Learning z Learning yrelatively permanent change in an organism’s behavior due to experience yexperience (nurture) is the key to learning Association zWe learn by association yOur minds naturally connect events that occur in sequence yAristotle 2000 years ago yJohn Locke and David Hume 200 yrs ago zAssociative Learning ylearning that two events occur together xtwo stimuli xa response and its consequences Association Event 1 Event 2 zLearning to associate two events Sea snail associates splash with a tail shock Seal learns to expect a snack for its showy antics Classical or Pavlovian Conditioning Two related events: Stimulus 1 Lightning Stimulus 2 Thunder Result after repetition Stimulus We see lightning Response We wince anticipating thunder zWe learn to associate two stimuli Operant Conditioning zWe learn to associate a response and its consequence Response: Pushing vending machine button Consequence: Receiving a candy bar Behaviorism zJohn B. Watson yviewed psychology as objective science xgenerally agreed-upon consensus today yrecommended study of behavior without reference to unobservable mental processes xnot universally accepted by all schools of thought today Classical or Pavlovian Conditioning zIvan Pavlov y1849-1936 yRussian physician/ neurophysiologist yNobel Prize in 1904 ystudied digestive secretions Pavlov’s Classic Experiment Before Conditioning UCS (food in mouth) UCR (salivation) During Conditioning Neutral stimulus (tone) No salivation After Conditioning UCS (food in mouth) Neutral stimulus (tone) UCR (salivation) CS (tone) CR (salivation) Classical or Pavlovian Conditioning zPavlov’s device for recording salivation Classical or Pavlovian Conditioning zClassical Conditioning yorganism comes to associate two stimuli xlightning and thunder xtone and food ybegins with a reflex ya neutral stimulus is paired with a stimulus that evokes the reflex yneutral stimulus eventually comes to evoke the reflex Classical or Pavlovian Conditioning zUnconditioned Stimulus (UCS) yeffective stimulus that unconditionallyautomatically and naturally- triggers a response zUnconditioned Response (UCR) yunlearned, naturally occurring automatic response to the unconditioned stimulus xsalivation when food is in the mouth Classical or Pavlovian Conditioning zConditioned Stimulus (CS) ypreviously neutral stimulus that, after association with an unconditioned stimulus, comes to trigger a conditioned response zConditioned Response (CR) ylearned response to a previously neutral conditioned stimulus Conditioning zAcquisition ythe initial stage of learning, during which a response is established and gradually strengthened yin classical conditioning, the phase in which a stimulus comes to evoke a conditioned response yin operant conditioning, the strengthening of a reinforced response Conditioning zExtinction ydiminishing of a CR yin classical conditioning, when a UCS does not follow a CS yin operant conditioning, when a response is no longer reinforced Classical or Pavlovian Conditioning Strength of CR Acquisition (CS+UCS) Extinction (CS alone) Spontaneous recovery of CR Extinction (CS alone) Pause Classical or Pavlovian Conditioning zSpontaneous Recovery yreappearance, after a rest period, of an extinguished CR zGeneralization ytendency for a stimuli similar to CS to evoke similar responses Classical or Pavlovian Conditioning zDiscrimination yin classical conditioning, the ability to distinguish between a CS and other stimuli that do not signal and UCS yin operant conditioning, responding differently to stimuli that signal a behavior will be reinforced or will not be reinforced Generalization Drops of saliva in 30 seconds 60 50 40 30 20 10 0 Hind paw Pelvis Thigh Shoulder Trunk Front paw Foreleg Part of body stimulated Classical or Pavlovian Conditioning UCS (passionate kiss) CS (onion breath) CS (onion breath) UCR (sexual arousal) UCS (passionate Kiss) CR (sexual arousal) UCR (sexual arousal) Nausea Conditioning in Cancer Patients UCS (drug) UCR (nausea) CS (waiting room) CS (waiting room) UCS (drug) UCR (nausea) CR (nausea) Operant Conditioning zOperant Conditioning ytype of learning in which behavior is strengthened if followed by reinforcement or diminished if followed by punishment zLaw of Effect yThorndike’s principle that behaviors followed by favorable consequences become more likely and behaviors followed by unfavorable consequences become less likely Operant Conditioning zOperant Behavior ycomplex or voluntary behaviors xpush button, perform complex task yoperates (acts) on environment yproduces consequences zRespondent Behavior yoccurs as an automatic response to stimulus ybehavior learned through classical conditioning Operant Conditioning zB.F. Skinner (1904-1990) yelaborated Thorndike’s Law of Effect ydeveloped behavioral technology Operant Chamber zSkinner Box ysoundproof chamber with a bar or key that an animal presses or pecks to release a food or water reward ycontains a device to record responses Operant Conditioning zReinforcer yany event that strengthens the behavior it follows zShaping yconditioning procedure in which reinforcers guide behavior toward closer approximations of a desired goal zSuccessive Approximations yreward behaviors that increasingly resemble desired behavior Principles of Reinforcement zPrimary Reinforcer yinnately reinforcing stimulus ysatisfies a biological need zSecondary Reinforcer yconditioned reinforcer ylearned through association with primary reinforcer Schedules of Reinforcement zContinuous Reinforcement yreinforcing the desired response each time it occurs ylearning occurs rapidly yextinction occurs rapidly zPartial Reinforcement yreinforcing a response only part of the time yresults in slower acquisition ygreater resistance to extinction Schedules of Reinforcement zFixed Ratio (FR) yreinforces a response only after a specified number of responses yfaster you respond the more rewards you get ydifferent ratios yvery high rate of responding ylike piecework pay Schedules of Reinforcement zVariable Ratio (VR) yreinforces a response after an unpredictable number of responses yaverage ratios ylike gambling, fishing yvery hard to extinguish because of unpredictability Schedules of Reinforcement zFixed Interval (FI) yreinforces a response only after a specified time has elapsed yresponse occurs more frequently as the anticipated time for reward draws near Schedules of Reinforcement zVariable Interval (VI) yreinforces a response at unpredictable time intervals yproduces slow steady responding ylike pop quiz Schedules of Reinforcement Number of responses 1000 Fixed Ratio Variable Ratio Fixed Interval 750 Rapid responding near time for reinforcement 500 Variable Interval 250 Steady responding 0 10 20 30 40 50 Time (minutes) 60 70 80 Punishment zPunishment yaversive event that decreases the behavior that it follows ypowerful controller of unwanted behavior Problems with Punishment zPunished behavior is not forgotten, it's suppressed- behavior returns when punishment is no longer eminent zCauses increased aggression- shows that aggression is a way to cope with problemsExplains why aggressive delinquents and abusive parents come from abusive homes Problems with Punishment zCreates fear that can generalize to desirable behaviors, e.g. fear of school, learned helplessness, depression zDoes not necessarily guide toward desired behavior- reinforcement tells you what to do-punishment tells you what not to doCombination of punishment and reward can be more effective than punishment alone zPunishment teaches how to avoid it Cognition and Operant Conditioning zCognitive Map ymental representation of the layout of one’s environment yexample- after exploring a maze, rats act as if they have learned a cognitive map of it zLatent Learning ylearning that occurs, but is not apparent until there is an incentive to demonstrate it Cognition and Operant Conditioning zOverjustification Effect ythe effect of promising a reward for doing what one already likes to do ythe person may now see the reward, rather than intrinsic interest, as the motivation for performing the task Latent Learning Average errors 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Days Operant vs Classical Conditioning Classical Conditioning Operant Conditioning The Response Involuntary, automatic “Voluntary,” operates on environment Acquisition Associating events; CS announces UCS. Associating response with a Consequence (reinforcer or punisher). Extinction CR decreases when CS is repeatedly presented alone. Responding decreases when reinforcement stops. Cognitive processes Subjects develop expectation that CS signals the arrival of UCS. Subjects develop expectation that a response will be reinforced or Punished; they also exhibit latent learning, without reinforcement Biological predispositions Natural predispositions contain what stimuli and responses can easily be associated. Organisms best learn behaviors similar to their natural behaviors; unnatural behaviors instinctively drift back toward natural ones. Observational Learning zObservational Learning ylearning by observing and imitating others zModeling yprocess of observing and imitating behavior zProsocial Behavior ypositive, constructive, helpful behavior yopposite of antisocial behavior