Learning Chapter 5
Define Learning • Learning is a relatively permanent change in behavior as a result of experience.
Associative Learning • learning that two events occur together • two stimuli • a response and its consequences
Conditioning • Conditioning is the process of learning associations.
ClassicalConditioning • In classical conditioning, we learn to associate two stimuli and anticipate events. • For example, we learn that a flash of lightening signals an impending crack of thunder, as so we start to brace ourselves when lightening flashes nearby.
Two related events: Stimulus 1 Lightning Stimulus 2 Thunder Result after repetition: Stimulus We see lightning Response We wince anticipating thunder
2 stimuli… First Stimulus - Yelling Word “Flush”… Second Stimulus - Hot Water! I RESPOND by jumping out of the way!
After this happens a few times…. I have been CONDITIONED to jump out of the way when I hear the word “Flush”!
Classical Conditioning • Ivan Pavlov - Russian; Medical doctor who spent two decades studying the digestive system. Nobel Prize in 1904. Studied learning for the next three decades, by “accident”.
Classical Conditioning • After studying salivary secretion in dogs, he knew that when he put food in a dog’s mouth the animal would invariably salivate. • He also began to notice that when he worked with the same dog repeatedly, the dog began salivating to stimuli associated with the food
Classical Conditioning • Pavlov’s Experiment: • Through experimentation, Pavlov asked: If a neutral stimulus(something the dog could see or hear that would not normally cause salivation) regularly signaled the arrival of food, would the dog associate the two stimuli (the food and the neutral stimuli)?
Link! Pavlov’s dogs get conditioned • What if we
Classical Conditioning involves: • Unconditioned Stimulus (UCS) • A stimulus that naturally and automatically triggers a response (usually a reflex) • Food in Pavlov’s case
Classical Conditioning • Unconditioned Response (UCR) • The unlearned, naturally occurring response to the unconditioned stimulus • Salivation in Pavlov’s case
Pavlov’s Experiment (continued): • Just before placing food in the dog’s mouth to produce salivation, Pavlov sounded a bell (Neutral Stimulus). After several pairings of bell and food, the dog began to salivate to the sound of the bell alone, in anticipation of the food.
Classical Conditioning • Conditioned Stimulus (CS) • An originally irrelevant (neutral) stimulus that, after association with an unconditioned stimulus, comes to trigger a conditioned response • The Bell in Pavlov’s case
Classical Conditioning • Conditioned Response (CR) • The learned response to a previously neutral conditioned stimulus • Salivation (to the bell)
Classical Conditioning • For example: • For Pavlov, the previously neutral stimulus was the tone. During conditioning, the tone was paired with the food (UCS). After conditioning, the tone, when presented alone, produced salivation in the dog. The tone is now considered the CS, and the dog’s salivation to the tone alone is now considered the CR.
UCS (passionate kiss) UCR (sexual arousal) CS (onion breath) UCS (passionate Kiss) UCR (sexual arousal) CS (onion breath) CR (sexual arousal)
UCS (drug) UCR (nausea) CS (waiting room) UCS (drug) UCR (nausea) CS (waiting room) CR (nausea)
Classical Conditioning – Extra • Baby Albert Experiment – Fear Conditioning • An 11-month infant named Albert feared loud noises, but not white rats. • In the experiment, when Albert was presented with a white rat and reached out to touch it, a hammer was struck on a steel beam behind his head.
Lets Review: What is the neutral stimulus that has now become a “conditioned stimulus?What is the “conditioned response” to that stimulus?
Five Major Conditioning Processes • Acquisition • Generalization • Discrimination • Extinction • Spontaneous Recovery
Acquisition The process of developing a learned response The subject learns a new response (CR) to a previously neutral stimulus (CS)
Acquisition • Findings: • The time between presenting the neutral stimulus and the unconditioned stimulus needs to be short. For most species and procedures, about ½ second works best. • Conditioning is not likely to occur if the conditioned stimulus is presented before the unconditioned stimulus
Give an Example • From what you know of classical conditioning, give an example of acquisition
Generalization • The tendency, once a response has been conditioned, for stimuli similar to the conditioned stimulus to elicit similar responses • IE. A child bitten by a dog may fear all dogs. • After 9/11, many people responded anxiously when planes flew near by. • Baby Albert
Classical Conditioning - Extra • Five days after the testing, Albert showed generalization of his conditioned response by reacting with fear to a rabbit, a dog, and a sealskin coat.
Discrimination • The learned ability to distinguish between a conditioned stimulus and other stimuli that do not signal an unconditioned stimulus • IE. A child bitten by a dog now fears all dogs. The same child learns, over time, that only certain types dogs should be feared (pit bull?), and others generally shouldn’t (golden retriever?).
Extinction and Spontaneous Recovery • After conditioning, what happens if the conditioned stimulus occurs repeatedly without the unconditioned stimulus…..will it continue to elicit the conditioned response?
Extinction • diminishing of a CR • in classical conditioning, when a UCS does not follow a CS – it breaks the association
Spontaneous Recovery • reappearance, after a rest period, of an extinguished CR • Review by watching this clip…
Acquisition (CS+UCS) Strength of CR Spontaneous recovery of CR Extinction (CS alone) Extinction (CS alone) Pause
Operant Conditioning • Type of learning in which behavior is strengthened if followed by a reward, or diminished if followed by a punisher
Operant Conditioning • We repeat behavior that is followed by a reward
Operant Conditioning • In operant conditioning, we learn to associate a response and its consequence, and we repeat acts followed by rewards, and avoid acts followed by punishment. • we learn that pushing a vending machine button relates to the delivery of a candy bar.
OH! THAT WAS A WONDERFUL, WONDERFUL REPORT The Vice-President in Charge of Sincerity
Operant Conditioning • B.F. Skinner’s Experiments: • Based on Edward Thorndike’s LAW OF EFFECT – states that rewarded behavior is likely to recur Click on my picture to learn about me! • Experiments conducted with animals in an operant conditioning chamber (Skinner Box) – a soundproof box, with a bar or key that an animal presses or pecks to release a reward of food or water
Oh, not bad. The light comes on, I press the bar, they write me a check. How about you?
Operant Conditioning • Shaping – while conditioning an animal to perform certain behaviors, reinforcers are successively given as the subject gets closer to the ultimate behavior goal • IE. If the purpose of putting a rat in a maze is to teach it to get from Point A to Point B while following a certain path • Every time the rat makes a turn towards the right path, a reward is given. If it makes a turn towards the wrong path, NO reward is given.