Chapter 6/9: Learning Learning A relatively durable change in behavior or knowledge that is due to experience. The acquisition of knowledge, skills, and behavior through reinforcement, modeling and natural learning. Classical Conditioning Learning in which a stimulus acquires the capacity to evoke a natural involuntary response that was originally evoked by another stimulus. Also known as Pavlovian conditioning. Ivan Pavlov- Russian physiologist Nobel Prize then Honorary Doctorate Cambridge University Classical Conditioning cont. Phobias- irrational fears of specific objects or situations ◦ Ex. Bridges, elevators, tunnels, heights, dogs, cats, bugs, snakes, doctors, and thunderstorms (NS) NS+UCS= Classical Conditioning cont. UCS_-> UCR NS-> Nothing NS+UCS-> UCR CS->CR Unconditioned stimulus (UCS)- a stimulus that evokes an unconditioned response without previous conditioning. (Food) Unconditioned response (UCR)- an unlearned reaction to an unconditioned stimulus that occurs without previous conditioning. (Saliva) Classical Conditioning cont. Conditioned stimulus (CS)- a previously neutral stimulus that has, through conditioning, acquired the capacity to evoke a conditioned response. (Bell) Conditioned response (CR)- a learned reaction to a conditioned stimulus that occurs because of previous conditioning. (saliva) Trial- any presentation of a stimulus or pair of stimuli NS+UCS Strength of the stimuli determines # of pairing needed for learning to take place Classical Conditioning cont. Classical Conditioning cont. Acquisition- the initial stage of learning Stimuli are contiguous if they occur together in time and space Extinction- the gradual weakening and disappearance of a conditioned response Spontaneous recovery- the reappearance of an extinguished response after a period of no exposure to the conditioned stimulus Renewal effect ◦ Extinction suppresses a conditioned response rather than erasing a learned association Classical Conditioning cont. Classical Conditioning cont. Stimulus generalization occurs when an organism has learned a response to a specific stimulus responds in the same way to new stimulus Watson and “Little Albert” Stimulus discrimination occurs when an organism that has learned a response to a specific stimulus does not respond in the same way to new stimuli that are similar to the original stimulus ◦ Animal’s survival relies on this by being able to distinguish friend from foe, or edible from poisonous food Classical Conditioning cont. Classical Conditioning cont. Higher-order conditioning- a conditioned stimulus functions as if it were an unconditioned stimulus ◦ New conditioned responses are built on the foundation of already established conditioned responses Operant Conditioning A form of voluntary learning in which responses come to be controlled by their consequences Christened “operant conditioning” by B.F. Skinner in the 1930s Also known as instrumental learning by Edward L. Thorndike Thorndike’s “puzzle box” experiments Law of effect- if a response in the presence of a stimulus leads to satisfying effects, the association between the stimulus and the response is strengthened Operant Conditioning cont. Skinner demonstrated that organisms tend to repeat those responses that are followed by favorable consequences. reward) Reinforcement occurs when an event following a response increases an organism’s tendency to make that response. Operant Conditioning cont. Operant Conditioning cont. An operant chamber, or Skinner box, is a small enclosure in which an animal can make a specific response that is recorded while the consequences of the response are systematically controlled. To emit means to send forth Reinforcement contingencies- the circumstances or rules that determine whether responses lead to the presentation of reinforcers. ◦ The experimenter manipulates whether positive consequences occur when the animal makes the designated response Operant Conditioning cont. The cumulative recorder creates a graphic record of responding and reinforcement in a Skinner box as a function of time. Shaping- the reinforcement of closer and closer approximations of a desired response. ◦ Necessary when an organism does not, on its own, emit the desired response. ◦ Sports, music, school. Gymnastics, track, martial arts, learning an instrument, math, language arts, etc. Operant Conditioning cont. Extinction refers to the gradual weakening and disappearance of a response tendency because the response is no longer followed by a reinforcer Resistance to extinction occurs when an organism continues to make a response after delivery of the reinforcer has been terminated Operant Conditioning cont. Skinner said that reinforcement occurs whenever an outcome strengthens a response, as measured by an increase in the rate of responding If a delay occurs between a response and the positive outcome, the response may not be strengthened Operant Conditioning cont. Primary reinforcers- events that are inherently reinforcing because they satisfy biological needs. ◦ Food, water, physical or emotional attention Secondary, or conditioned, reinforcers are events that acquire reinforcing qualities by being associated with primary reinforcers. ◦ Money, tokens, privileges ◦ Big Bang theory season 3 episode 3 Operant Conditioning cont. A schedule of reinforcement determines which occurrences of a specific response result in the presentation of a reinforcer ◦ Continuous reinforcement occurs when every instance of a designated response is reinforced ◦ Intermittent, or partial, reinforcement occurs when a designated response is reinforced only some of the time Operant Conditioning cont. Schedules of Reinforcement Fixed-ratio (FR) schedule- the reinforcer is given after a fixed number of responses. ◦ Rat given food after pressing the lever a set number of times. ◦ Being paid for painting a house not by hour but by job. Variable-ratio (VR) schedule- the reinforcer is given after a variable number of responses. ◦ Slot machines ◦ Fly fishing Fixed-interval (FI) schedule- the reinforcer is given for the first response that occurs after a fixed time interval has elapsed. ◦ Being paid every 2 weeks. Variable-interval (VI) schedule- the reinforcer is given for the first response after a variable time interval has elapsed. ◦ Being rewarded randomly. ◦ Fishing ◦ Surfing?????? Schedules of Reinforcement (con’t) Contingencies of Reinforcement Positive reinforcement occurs when a response is strengthened or increases because it is followed by the presentation of a rewarding stimulus. ◦ Money, food, tokens, praise Negative reinforcement occurs when a response is strengthened or increases because it is followed by the removal of an aversive stimulus. ◦Putting your seatbelt on to stop the buzzing Contingencies of Reinforcement Punishment – Occurs when an event following the response weakens or decreases the tendency to make that response. ◦ Beatings, loud noises, taking away privileges, being grounded, being yelled at, paying a fine, community service. Escape learning- an organism acquires a response that decreases or end some aversive stimulation Avoidance learning- an organism acquires a response that prevents some aversive stimulation from occurring Operant Conditioning cont. Observational Learning Occurs when an organism’s responding is influenced by the observation of others, who are called models Albert Bandura Both classical and operant conditioning can take place in observational learning Ratings on TV. Involves the process of learning to copy or model the action of another through observing another doing it. Thought to be particularly important during childhood, particularly as authority becomes important The best role models are those a year or two older for observational learning Observational Learning cont. 4 key processes of observational learning ◦ Attention: ◦ Retention: ◦ Reproduction: ◦ Motivation: Observational Learning cont. Bandura's Bobo doll experiment is widely cited in psychology as a demonstration of observational learning and demonstrated that children are more likely to engage in violent play with a life size rebounding doll after watching an adult do the same It may be that children will only reproduce a model's behavior if it has been reinforced Observational Learning cont. .