Modules 20 – 22 Learning Theory
Introduction • Learning: relatively permanent changes in behavior due to experience • Measured objectively (i.e., behavior must be observable and recordable) • Behaviorist perspective
Introduction—How do we learn? • Conditioning: process by which associations are learned • Two types: Classical conditioning and operant conditioning • Classical Conditioning: two stimuli are associated to produce behavior • Operant conditioning: consequence is associated with the behavior • Observational Learning: learn by watching others’ behaviors
Classical Conditioning:Introduction • Ivan Pavlov • Russian physiologist • Studied digestion in dogs • Discovered dogs were salivating in response to experimenter’s footsteps in anticipation of food • Called these “psychic secretions”
Classical Conditioning: Introduction • Classical conditioning: type of learning in which one stimulus is associated with another • Learning occurs through repeated pairings of neutral stimulus (footsteps) with natural stimulus (food) • Most basic form of learning • Also called Pavlovian Conditioning or Respondent Conditioning
Classical Conditioning:Important Terms • Unconditioned stimulus (UCS): stimulus that triggers response • Unconditioned response (UCR): unlearned or natural response to UCS (reflex) • Conditioned stimulus (CS): neutral stimulus that comes to elicit (cause) conditioned response • Conditioned response (CR): learned response to previously neutral stimulus (CS)
Classical Conditioning:Paradigm • Before Conditioning • UCS → UCR CS → No response • During Conditioning • CS + UCS → UCR • After Conditioning • CS → CR
Classical Conditioning:Paradigm with example • Before Conditioning • Food (UCS) → Salivation (UCR) Bell (CS) → No response • During Conditioning • Bell (CS) + Food (UCS) → Salivation (UCR) • After Conditioning • Bell (CS) → Salivation (CR) • Video Clip: http://www.youtube.com/watch?v=CpoLxEN54ho
Classical Conditioning:Examples • Fears and phobias • Food aversions (one-trial learning) • Dentist’s drill • Police sirens and lights • Others???
Find the UCS, UCR, CS, CR in the following: The door to your house squeaks loudly when you open it. Soon, your dog begins wagging its tail when the door squeaks. The nurse says, “This won’t hurt a bit,” just before stabbing you with a needle. The next time you hear “This won’t hurt,” you cringe in fear. You have a meal at a fast food restaurant that causes food poisoning. The next time you see a sign for that restaurant, you feel nauseated.
Classical Conditioning:Types (in order of best learning) • Delayed conditioning: CS precedes and overlaps presentation of UCS • Simultaneous conditioning: CS and UCS presented at same time (begin and end simultaneously) • Trace conditioning: CS presented and stops with gap before presentation of UCS • Backward conditioning: UCS presented before CS
Basic Principles of Learning • Acquisition = how is it learned • Extinction = how is it “forgotten” • Generalization = when is response also given • Discrimination = when is it given only in specific situations
Classical Conditioning: Acquisition • Acquisition: how is beh learned • Conditioning occurs because of repeated pairings of CS and UCS • Learn association btn CS and UCS • Learning curve increases rapidly and then levels off
Classical Conditioning:Factors that affect Acquisition • Order and timing of CS and UCS • Most important—critical for learning • Delayed conditioning is best • CS seems to signal UCS but needs to overlap to be associated • Intensity of CS and UCS (food aversions) • How connected are CS and UCS → how well does CS predict UCS
Classical Conditioning:Extinction • Extinction: elimination of learned response due to removal of UCS • Gradual process • Does not erase what is learned • Spontaneous recovery: re-emergence of extinguished response after period of time away (CR is not as intense)
Classical Conditioning:Generalization • Generalization: tendency to respond to stimuli that are similar to CS • In Pavlov’s experiment, dog would salivate to different tones • Other examples: • Food aversions start with one type of seafood and are associated with others • Phobias • Others ???
Classical Conditioning:Discrimination • Discrimination: tendency not to respond to similar stimuli, but only to original CS • In Pavlov’s experiments, dog was trained to salivate only to certain tone. • Examples • Food aversions in some cases, may only respond to fish but will eat shellfish • Others ???
Classical Conditioning:Higher-Order Learning • Can CS become UCS? • Yes • Higher-order conditioning: by pairing learned CS with new stimulus, the original CS acts as the UCS • Example – dog salivates to bell and then bell is paired with light
Classical Conditioning:Applications • Phobias: extreme fear of specific stimulus • John Watson’s research (Little Albert) • Wanted to demonstrate behavioral explanation for phobias • Created phobia in Little Albert • Ways to treat phobias have been developed using the principles of Classical Conditioning
Classical Conditioning:Systematic Desensitization • Systematic Desensitization: decreases phobic response by substituting an incompatible response • Works by re-conditioning/re-learning • Process: • Client creates hierarchy of fear-producing stimuli • Learns progressive muscle relaxation • Begins with lowest stimuli on hierarchy and tries to substitute relaxation • Continue up hierarchy until actually dealing with stimulus
Classical Conditioning:Flooding • Flooding: fear-producing stimuli presented continuously until fear response decreases until extinguished • Uses principle of extinction to treat phobia
Classical Conditioning:Other applications • Advertisements • Social attitudes
Classical Conditioning Video Links • http://www.youtube.com/watch?v=TJ3dLm2j5uk • http://www.youtube.com/watch?v=e1g3y0SRbVc • Frasier: http://www.youtube.com/watch?v=2c4_l2oe22U • The Office: http://vimeo.com/35754924 • Dog training: http://www.youtube.com/watch?v=tPAnp6Oxc6E
New Major Topic: Operant Conditioning • Classical Conditioning involved learning through association of neutral stimulus with a stimulus that caused a reflexive response. • Operant Conditioning involves learning through the connection of a consequence with a behavior.
Operant Conditioning:EL Thorndike and Trial-and-Error Learning • Research • Placed cat in “puzzle box” • Cat needed to hit lever to open door to get food • With successive trials, cat would hit lever sooner • Law of effect: beh followed by satisfying outcome is stamped in or repeated, while behaviors followed by negative or no outcome are extinguished • Video clip
Operant Conditioning: Introduction—BF Skinner • B.F. Skinner • Behaviorist • Major books: Beyond Freedom and Dignity and Walden Two • Skinner box: structured environment that allowed for control of response and outcome
Operant Conditioning: Introduction—Definition • Operant conditioning: process by which organism learns to behave in ways that produce desirable outcomes • Other ways to say this: • Learning to behave because of effects/results of beh • Beh influenced by consequences
Operant Conditioning: Paradigm S + R → R+ • S = stimulus • Something that signals that reinforcement is likely if you respond, • R = response • Specific behavior • R+ = reinforcement • Consequence of beh that increases likelihood that beh is repeated
Operant Conditioning:Reinforcement • Reinforcement: anything that increases likelihood that beh will be repeated • Primary and secondary reinforcement (more later) • Positive and negative reinforcement (more later)
Operant Conditioning:Reinforcement (cont’d) • Primary versus secondary reinforcement • Primary reinforcement: anything that is naturally reinforcing or automatically reduces drive or need (e.g., food, warmth, attention) • Secondary reinforcement: anything that has acquired ability to be reinforcing (e.g., money, stickers, etc.)
Operant Conditioning:Reinforcement (cont’d) • Positive and negative reinforcement • Positive reinforcement: addition of stimulus that increases likelihood beh is repeated • Negative reinforcement: removal of stimulus that increases likelihood beh is repeated
Operant Conditioning:Punishment • Punishment: any stimulus that decreases likelihood that beh is repeated • Positive punishment: addition of stimulus to decrease behavior • Negative punishment: removal of stimulus to decrease behavior
Operant Conditioning:Avoidance and Escape Learning • Escape learning: When our response to aversive stimulus (something we don’t like) removes that stimulus • Example → parents yelling at you b/c you came home late • You apologize and say it will not happen again • So, they STOP yelling at you
Operant Conditioning:Avoidance and Escape Learning (cont’d) • Avoidance learning: when our response prevents aversive stimulus (consequence) from occurring • Example → You come home late. • You apologize to your parents BEFORE they begin to yell at you. • They do not yell at you
Operant Conditioning:Schedules of reinforcement • Introduction • How often beh is reinforced has influence • Discovered by accident out of necessity • Financial concerns required Skinner not to reinforce every behavior • Led to hypothesis concerning the impact of altering how often behavior is reinforced • Continuous reinforcement: reward given for beh every single time • Partial (or intermittent) reinforcemetn: reward given part of the time • Two ways to vary how often • According to number of responses (ratio) • According to when response occurs (interval)
Operant Conditioning:Schedules of reinforcement (cont’d) • Fixed ratio: reinforcement given after set # of responses • Response-to-reinf ratio remains constant • Tend to see burst of responses until reinforced, then see pause in response rate • Examples → CD clubs, frequent flyer miles • Variable ratio: reinforcement given after varying/changing # of responses • Constant high rate of response (WHY?) • Examples → slot machine
Operant Conditioning:Schedules of reinforcement (cont’d) • Fixed interval: reinf. given for first response given after set time period • “Wait for it.” • Produces slow, scalloped response pattern • Learn that certain period of time must pass • Examples → Tests on every Friday • Fixed interval: reinf. given for first response given after set time period • Variable interval: reinf. given for first response after varying period of time • Slow but steady response patterns • Examples → pop quizzes • Video clip
Identify the schedule of reinforcement–Fixed Ratio, Variable Ratio, Fixed Interval, or Variable Interval FR FI FR VR VI/VR VI FR VR VR FI • Rat gets food every third time it presses the lever • Getting paid weekly no matter how much work is done • Getting paid for every ten boxes you make • Hitting a jackpot sometimes on the slot machine • Winning sometimes on the lottery you play once a day • Checking cell phone all day; sometimes getting a text • Buy eight pizzas, get the next one free • Fundraiser averagesone donation for every eight houses visited • Kid has tantrum, parents sometimes give in • Repeatedly checking mail until paycheck arrives
Operant Conditioning:Principles of Learning • Acquisition • Shaping: reinforce successive approximations of desired beh • Reinforce initially for getting close • Video clips • Teaching pigeon to play ping pong • Dog agility training • Fred
Operant Conditioning:Principles of Learning • Acquisition (cont’d) • Effect of schedule of reinforcement on acquisition • Quickest learning → continuous reinforcement (every beh) • Strongest overall response → variable (partial reinforcement) schedules • Reinforcement versus punishment • Reinforcement works best • Reinf demonstrates correct response
Operant Conditioning:Principles of Learning (cont’d) • Extinction: elimination of learned response b/c it is not longer reinforced • Extinction happens most quickly in fixed ratio schedule of reinf • Extinction < likely with variable schedules—WHY? • Partial reinforcement is best to avoid extinction • Spontaneous recovery: return of extinguished response after rest period (you never forget how to ride a bike)
Operant Conditioning:Principles of Learning (cont’d) • Generalization: learning to respond to similar stimuli • Example → studying in Psych leads to good grades, so now you study in other classes • Discrimination: learning to respond differently to similar stimuli • Example → how you act in one class versus another
Operant Conditioning:Applications • Behavior Modification/Behavior change • Behavior modification: use of operant conditioning principles to change or modify beh • Token economy • Examples → Villa Maria’s behavior mod program • Video clip: Big Bang Theory • Video Clip: Cheers Shock Therapy • Depression • Martin Seligman’s research • Learned helplessness: ind learns that response is not connected to outcome • So, they stop responding • Superstitions • Others • Video
Operant Conditioning Videos • Intro: http://www.youtube.com/watch?v=B8vIbuoktew • Shaping: http://www.youtube.com/watch?v=OCUWHP4YDgU • Schedules of Reinforcement: http://www.youtube.com/watch?v=i0ad2NSwGb0
Contrasting Types of Conditioning Organism associates events.
New Major Topic:Cognitive Factors in Learning • Classical Conditioning and Operant Conditioning => ind must experience conditioning directly • Social Learning Theory (subtopic) • Cognitive Maps (subtopic)
Social Learning Theory:Introduction • Albert Bandura • Bobo Doll studies • Children observed live model hitting bobo clown doll • After observing this, they were given opportunity to play in the room with bobo doll • Children engaged in similar behavior • Even when they had witnessed aggression against a live clown