720 likes | 936 Vues
Cat Video. Cat Roundup. Learning. Learning Lasting change in an organism’s behavior due to experience. Association. We learn by association Our minds naturally connect events that occur in sequence Aristotle 2000 years ago John Locke and David Hume 200 years ago Associative Learning
E N D
Learning • Learning • Lasting change in an organism’s behavior due to experience
Association • We learn by association • Our minds naturally connect events that occur in sequence • Aristotle 2000 years ago • John Locke and David Hume 200 years ago • Associative Learning • learning that two events occur together • two stimuli • a response and its consequences
Association Event 1 Event 2 • Learning 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 • We learn to associate two stimuli
Operant Conditioning • We learn to associate a response and its consequence
Classical Conditioning • Classical Conditioning • organism comes to associate two stimuli • a neutral stimulus that signals an unconditioned stimulus begins to produce a response that anticipates and prepares for the unconditioned stimulus Ivan Pavlov
Classical Conditioning • Ivan Pavlov • 1849-1936 • Russian physician/ neurophysiologist • Nobel Prize in 1904 • studied digestive secretions
Classical Conditioning • Pavlov’s device for recording salivation
Pavlov’s Classic Experiment Before Conditioning UCS (food in mouth) Neutral stimulus (tone) UCR (salivation) No salivation During Conditioning After Conditioning UCS (food in mouth) CS (tone) Neutral stimulus (tone) UCR (salivation) CR (salivation)
CONDITIONED RESPONSE will elicit UNCONDITIONED STIMULUS UNCONDITIONED STIMULUS REFLEX ACTION REFLEX ACTION CONDITIONED STIMULUS NO REACTION NEUTRAL STIMULUS NEUTRAL STIMULUS will elicit a will elicit a will elicit a CONDITIONED STIMULUS Classical Conditioning
Classical Conditioning • Unconditioned Stimulus (UCS) • stimulus that unconditionally--automatically and naturally--triggers a response In Pavlov’s experiments the food was the UCS • Unconditioned Response(UCR) • unlearned, naturally occurring response to the unconditioned stimulus • salivation when food is in the mouth • UCS-UCR connection involves no learning
Classical Conditioning • Conditioned Stimulus (CS) • originally irrelevant stimulus that, after association with an unconditioned stimulus, comes to trigger a conditioned response the tone produced • Conditioned Response (CR) • learned response to a previously neutral conditioned stimulus Salivation when bell rings.
Classical Conditioning • Acquisition • the initial stage in classical conditioning • the phase associating a neutral stimulus with an unconditioned stimulus so that the neutral stimulus comes to elicit a conditioned response • in operant conditioning, the strengthening of a reinforced response
UCS (passionate kiss) UCR (sexual arousal) CS (onion breath) UCS (passionate Kiss) UCR (sexual arousal) CS (onion breath) CR (sexual arousal) Classical Conditioning
Classical Conditioning • Extinction • diminishing of a CR • in classical conditioning, when the presentation of CS without the UCS • in operant conditioning, when a response is no longer reinforced
Classical Conditioning Acquisition (CS+UCS) Strength of CR Spontaneous recovery of CR Extinction (CS alone) Extinction (CS alone) Pause Acquisition CS+UCS Extinction CS alone Spontaneous recovery
Variations Within Classical Conditioning Extinction If a stimulus is never reinforced, then the response will go away. Spontaneous Recovery After extinction, a response will suddenly reappear. Learn not to respond to CS. Generalization A response can be generalized to other like stimuli. All spiders are scary.
Generalization is a behavior that spreads from one situation to a similar one. (A baby will call Daddy “Dada.” When the baby sees any man, the baby calls out “Dada.”) Discrimination is the reverse of generalization. Some stimuli have pleasant consequences and some do not. (A baby gradually learns that only one person responds with a smile when called “Dada.”)
Cognitive Processes Conditioning occurs best when the CS and UCS have just the sort of relationship that would lead a scientist to conclude that the CS causes the UCS. — even in classical conditioning, it is not only the simple stimulus-response association but also the thought that counts. • Conditioning in advertising
Biological Predispositions • John Garcia Conditioned taste aversions • Not all neutral stimuli can become conditioned stimuli. • Internal stimuli—associate better with taste • External stimuli—associate better with pain • Biological preparedness
UCS (drug) UCR (nausea) CS (waiting room) UCS (drug) UCR (nausea) CS (waiting room) CR (nausea) Nausea Conditioning in Cancer Patients
Behaviorism • John B. Watson • viewed psychology as objective science • generally agreed-upon consensus today • recommended study of behavior without reference to unobservable mental processes • not universally accepted by all schools of thought today
Watson took a a baby named Albert and conditioned him to be afraid of white furry objects using Pavlov’s techniques. Watson & Raynor with Little Albert
Conditioned fear experiments such as Albert’s experience would never occur today because of the existing ethical standards. Conditional Training: Albert and Peter
Mary Cover Jones Mary Cover Jones used an early form of desensitization to prove that fears (phobias) could be unlearned. Peter, a young boy, had an extreme fear of rabbits. Jones gave Peter his favorite food while slowly bringing the rabbit closer and closer. Eventually Peter no longer panicked around rabbits.
1. By learning to associate a squirt of water with electric shock, sea snails demonstrate the process of: a. habituation b. spontaneous recovery c. classical conditioning d. observational learning e. operant conditioning 2. John B. Watson considered himself to be a(n): a. Physiological psychologist b. Cognitive psychologist c. Behaviorist d. Psychoanalyst e. Operant conditioner 3. In Pavlov’s experiments, the dog’s salivation triggered by the taste of food was a(n): a. Conditioned response. b. Unconditioned stimulus. c. Unconditioned response. d. Conditioned stimulus. 4. In Pavlov’s experiments, the dog’s salivation triggered by the sound of the tone was a(n): a. Conditioned response. b. Unconditioned stimulus. c. Unconditioned response. d. Conditioned stimulus. 5. If a bell causes a dog to salivate because it has regularly been associated with the presentation of food, the bell is called a(n): a. Unconditioned stimulus. b. Conditioned stimulus. c. Primary reinforcer. d. Immediate reinforcer.
6. The initial stage of classical conditioning during which a response to a neutral stimulus is established and gradually strengthened is called: a. Acquisition. b. Association. c. Observational learning. d. Shaping. 7. When a CS is not followed by a UCS, the subsequent fading of a CR is called: a. Discrimination. b. Generalization. c. Delayed reinforcement. d. Extinction. 8. The reappearance, after a time lapse, of an extinguished CR is called: a. Generalization. b. Spontaneous recovery. c. Secondary reinforcement. d. Latent learning. e. Shaping. 9. The tendency for a CR to be evoked by stimuli similar to the CS is called: a. Generalization. b. Secondary reinforcement. c. Latent learning. d. Spontaneous recovery. e. Shaping. 10. The ability to distinguish between a conditioned stimulus and similar stimuli that do not signal an unconditioned stimulus is called: a. Shaping. b. Acquisition. c. Discrimination. d. Generalization. e. Latent learning. 11. Little Albert developed a fear of rats after a white rat was presented with a loud noise. In this case, the loud noise was the: a. Unconditioned stimulus. b. Conditioned stimulus. c. Secondary reinforcer. d. Delayed reinforcer.
Operant Conditioning • Operant Conditioning • type of learning in which behavior is strengthened if followed by reinforcement or diminished if followed by punishment • Law of Effect • Thorndike’s principle that behaviors followed by favorable consequences become more likely, and behaviors followed by unfavorable consequences become less likely
Operant Conditioning • Operant Behavior • operates (acts) on environment • produces consequences • Respondent Behavior • occurs as an automatic response to stimulus • behavior learned through classical conditioning
First Trial in Box After Many Trials in Box Scratch at bars Scratch at bars Situation: stimuli inside of puzzle box Situation: stimuli inside of puzzle box Push at ceiling Push at ceiling Dig at floor Dig at floor Howl Howl Etc. Etc. Etc. Etc. Press lever Press lever Early Operant Conditioning • E. L. Thorndike (1898) • Puzzle boxes and cats
Operant Conditioning • B.F. Skinner (1904-1990) • elaborated Thorndike’s Law of Effect • developed behavioral technology
Operant Chamber • Skinner Box • chamber with a bar or key that an animal manipulates to obtain a food or water reinforcer • contains devices to record responses
Operant Conditioning In shaping, successively closer versions of a desired response are reinforced (as in learning to play tennis). In chaining, each part of a sequence is reinforced; the different parts are put together into a whole (as in learning the steps to a dance).
Operant Conditioning • Positive Reinforcement • any event that strengthens the behavior it follows • Negative Reinforcement • The removal of a punishment or an aversive stimulus • It STRENGTHENS behavior
Operant Conditioning Processes Primary Reinforcement is unlearned and usually necessary for survival. Food is the best example of a primary reinforcer. Secondary Reinforcement is anything that comes to represent a primary reinforcer such as praise from a friend or a gold star on a homework assignment. Also called conditioned reinforcer.
Schedules of Reinforcement • Immediate Reinforcers • To our detriment, small but immediate reinforcements are sometimes more alluring than big, but delayed reinforcements • Continuous Reinforcement • reinforcing the desired response each time it occurs Learning occurs rapidly, but rapid extinction. This is the best way master behavior. • Partial (Intermittent) Reinforcement • reinforcing a response only part of the time • results in slower acquisition • greater resistance to extinction Hope springs eternal slot machines. Giving in to tantrums or students will.
Schedules of Reinforcement • Fixed Ratio (FR) • reinforces a response only after a specified number of responses • faster you respond the more rewards you get • different ratios • very high rate of responding • like piecework pay paid after producing 30 lamps
Schedules of Reinforcement • Variable Ratio (VR) • reinforces a response after an unpredictable number of responses • average ratios • like gambling (slots), fishing winning the derby • very hard to extinguish because of unpredictability
Schedules of Reinforcement • Fixed Interval (FI) • reinforces a response only after a specified time has elapsed • response occurs more frequently as the anticipated time for reward draws near. Mail comes a noon