Psychology: Pavlov, Watson, Skinner Learning Experiments and Concepts.

Psychology: Pavlov, Watson, SkinnerLearning Experiments and

Concepts

Classical Conditioning

• PAVLOV’S DOGClassical conditioning was accidentally discovered around the beginning of the 20th century by Russian physiologist Ivan Pavlov. Pavlov was studying digestive process in dogs when he discovered that the dogs salivated before they received their food. In fact, after repeated pairing of the lab attendant and the food, the dogs started to salivate at the sight of the lab assistants. Pavlov coined this phenomena “psychic secretions." He noted that dogs were not only responding to a biological need (hunger), but also a need developed by learning. Pavlov spent the rest of life researching why this associate learning occurred, which is now called classical conditioning.

Pavlov’s Dog


• PAVLOV’S DOG

To experiment on classical conditioning, Pavlov utilized a tuning fork and meat powder. He hit the tuning fork and followed the sound with the meat powder. Pavlov presented the sound (tuning fork) with the meat powder at the exact same time increments. In the beginning, the dog salivated only to the meat powder, but after this was repeated, salivated at the sound of the tuning fork. Even when Pavlov took away the meat powder, the dog continued to salivate at the sound of the tuning fork.


• PRINCIPLES OF CLASSICAL CONDITIONINGIn classical conditioning, an organism learns to associate one stimulus with another. The organism learns that the first stimulus is a cue for the second stimulus. In Pavlov’s experiment above, the tuning fork cued the dogs that food might be coming. Following is an example of classical conditioning.



• PAVLOV’S DOG

In technical terms, the food is an unconditioned stimulus (UCS) and the salivation is the unconditioned response (UCR). The bell is a neutral stimulus until the dog learns to associate the bell with food. Then the bell becomes a conditioned stimulus (CS) which produces the conditioned response (CR) of salivation after repeated pairings between the bell and food.

Pavlov’s Dog

Classical Conditioning Works On People, too


• WATSON’S BABY ALBERTJohn B. Watson was interested in how classical conditioning could be applied to humans. In 1921, Watson and his research assistant Rosalie Rayner experimented on a 11-month-old infant named Albert. The goal was to condition Albert to fear a white rat by paring the white rat with a loud bang (UCS). Initially, Albert showed no fear of rats, but once the rat was repeatedly paired with the loud noise (UCS), Albert developed a fear of rats. The noise (UCS) induced fear (UCR). After pairings between the loud noise (UCS) and the rat (CS), Albert started to fear the rat. Watson’s experiment suggested that classical conditioning could cause some phobias.

John Watson’s Little Albert Experiment

CLASSICAL CONDITIONING • KEY CONCEPTS OF CLASSICAL CONDITIONING• Unconditioned Stimulus (UCS)

A stimulus that elicits a response without conditioning

Unconditioned Response (UCR)Automatic response elicited by the unconditioned stimulus

Conditioned Stimulus (CS)A neutral stimulus that when paired with an unconditioned stimulus (UCS) elicits a similar response

• Conditioned Response (CR)A response that is learned by pairing the originally neutral conditioned stimulus (CS) with theunconditioned stimulus (UCS)

Perhaps Psychology’s most famous Experiment

CLASSICAL CONDITIONING• Acquisition

The acquisition phase is the consistent parings of the CS (bell) and the UCS (food) that produces a CR (salivation). In the example above, this phase occurs when the dog begins to salivate at the sound of the bell. Conditioning occurs more rapidly when the food follows the bell by a half a second.

• ExtinctionThe extinction phase is when the conditioned response no longer occurs after repeated pairings without the unconditioned stimulus. The dog’s response to the bell can be extinguished by repeatedly presenting the bell (CS) without the food (UCS). The dog has not completely forgotten the association between the bell and the food. If the experimenter waits a day, the dog may have a spontaneous recovery of the conditioned response and salivate again to the bell.

CLASSICAL CONDITIONING• Generalization

Occurs when there is a small difference in the presented stimulus and the original conditioned stimulus. If Pavlov’s dog heard a bell of a similar tone, the dog would still salivate.

• DiscriminationThe opposite of generalization, discrimination happens when a conditioned response does not occur when there is a difference between the presented stimulus and the original conditioned stimulus. If Pavlov’s dog heard a bell with a different tone and was not awarded the unconditioned stimulus (food), the dog would learn not to salivate to the second tone.

Operant Conditioning• SKINNER’S OPERANT CONDITIONING

Beginning in the 1930’s, Skinner started his experimentation on the behavior of animals. Skinner's quest was to observe the relationship between observable stimuli and response. Essentially, he wanted to know why these animals behaved the way that they do. Skinner controlled his experiments by using “Skinner boxes.” The Skinner box was a contraption that would automatically dispense food pellets and electric shocks. Skinner believed that the learning he observed in his Skinner boxes could apply to human behavior. He called this learning operant conditioning. Operant conditioning can be described as behavior adjustments as a result of greater or lesser negative or positive reinforcement and punishment. Skinner hypothesized that human behaviors were controlled by rewards and punishment and that their behaviors can be explained by principles of operant conditioning

Operant Conditioning


• PRINCIPLES OF OPERANT CONDITIONING

• The main principles of operant conditioning, as defined by Skinner, are reinforcement, punishment, shaping, extinction, discrimination, and generalization.

Punishers

Punisher

• Ok, who wasn’t expecting that?


• KEY CONCEPTS OF OPERANT CONDITIONING• Reinforcement

The process in which a behavior is strengthened, and thus, more likely to happen again.

• Positive ReinforcementMaking a behavior stronger by following the behavior with a pleasant stimulus. For example, a rat presses a lever and receives food.

• Negative ReinforcementMaking a behavior stronger by taking away a negative stimulus. For example, a rat presses a lever and turns off the electric shock

Positive Reinforcement

Punisher

Negative Reinforncement

B.F. Skinner

Operant Conditioning• Punishment

The process in which a behavior is weakened, and thus, less likely to happen again.

• Negative Punishment Reducing a behavior by removing a pleasant stimulus when the behavior occurs. If the rat was previously given food for each lever press, but now receives food consistently when not pressing the lever (and not when it presses the lever), the rat will learn to stop pressing the lever.

• Positive PunishmentReducing a behavior by presenting an unpleasant stimulus when the behavior occurs. If the rat previously pressed the lever and received food and now receives a shock, the rat will learn not to press the lever.

Operant Conditioning• Shaping

Technique of reinforcement used to teach new behaviors. At the beginning, people/animals are reinforced for easy tasks, and then increasingly need to perform more difficult tasks in order to receive reinforcement. For example, originally the rat is given a food pellet for one lever press, but we gradually increase the number of times it needs to press to receive food, the rat will increase the number of presses.

• ExtinctionThe elimination of the behavior by stopping reinforcement of the behavior. For example, a rat who received food when pressing a bar, receives food no longer, will gradually decrease the amount of lever presses until the rat eventually stops lever pressing.

Shaping


• Generalization In generalization, a behavior may be performed in more than one situation. For example, the rat who receives food by pressing one lever, may press a second lever in the cage in hopes that it will receive food.

• DiscriminationLearning that a behavior will be rewarded in one situation, but not another. For example, the rat does not receive food from the second lever and realizes that by pressing the first lever only, he will receive food.

• Fast Facts AboutIVAN PAVLOV

(1849- 1936)

Pavlov

Pavlov• Ivan Petrovich Pavlov was born on September 14, 1849, in Ryazan,

Russia.

Pavlov’s father was the local priest and worked in the fields with his mother during the day.

• In 1870, Pavlov abandoned his studies in religion and enrolled in the University of St. Petersburg. Inspired by the ideas of I.M. Sechenov, the father of Russian physiology, he enrolled in natural science courses.

• In 1875, he graduated with a degree of Candidate of Natural Sciences; however, wanting more education in physiology, Pavlov enrolled in the Academy of Medical Surgery. In 1879, he was awarded another gold medal.

• In 1881, Pavlov married Seraphima Vasilievna Karchevskaya, a teacher and had five children: Wirchik, Vladimir, Victor, Vsevolod, and Vera. Wirchik died in childhood.

Pavlov

• In 1890, Pavlov was appointed as a professor at St. Petersburg Military-Medical Academy.

• During 1891-1900, at the Institute of Experimental Medicine, Pavlov conducted his research on the physiology of digestion.

• In 1901, Pavlov was elected as corresponding member of the Russian Academy of Sciences.

• In 1904, during his Nobel Prize address, Pavlov introduced his findings on conditioned reflexes.

Pavlov

• In 1907, Pavlov was elected Academician of the Russian Academy of Sciences.

• In 1912, Pavlov received an honorary doctorate degree from Cambridge University.

• In 1915, Pavlov was awarded the Order of the Legion of Honour.

• Pavlov died on February 27, 1936 in Leningrad.

• Fast Facts AboutJOHN B. WATSON

(1878-1958)

Watson• John Broadus Watson was born on January 9, 1878, near

Greenville, South Carolina to Emma and Pickens Watson.

• Watson's mother, who was very religious, named John after a local minister.

• Watson's father, Pickens, had extra-marital affairs and left the family in 1891.

• With the absence of his father during childhood, Watson often rebelled and was once arrested for shooting a gun.

Watson• Watson was accepted to Greenville’s Furman University as a sub-

freshman. • Watson had planned to attend Princeton Theological Seminary to

become a clergyman but was held back a year for handing in his philosophy-psychology exam backwards.

• In an attempt to upstage his instructor, Gordon Moore, Watson decided to pursue a Ph.D. in philosophy-psychology (something Moore did not have).

• With the help of Moore, Watson was admitted to the philosophy-psychology department at the University of Chicago. It was at the University of Chicago where Watson began his experiments on animals.

Watson• Watson received his doctorate at the University of Chicago in 1903.

At the University of Chicago, Watson was a departmental star being the youngest student with a Ph.D. at the university and had the second-best final exam in the history of the department.

• Watson married Mary Ickes in December 1903. They had two children, Mary and John.

• In 1903, Watson accepted a professor of psychology position at Johns Hopkins University.

• After a year at John Hopkins University, Watson became the department leader and editor of the Psychological Review.

Watson

• In 1913, Watson published the article “Psychology as the Behaviorist Views It."

• In 1915, Watson became the President of the American Psychological Association.

• Watson enlisted in the Signal Corps in 1917 during World War I.

• In 1920, he published his experiments on “Little Albert” with Rosalie Rayner.

• John Hopkins University forced Watson to resign after finding out that he had an affair with Rayner. Watson and Mary divorced and married Rayner. Watson and Rayner had two children, James and William.

Watson

• Watson was offered a job at the J. Walter Thompson advertising agency for $25,000 a year (four times his professor’s salary). In 1924, Watson became vice-president of the agency.

• Watson continued to publish psychological works, but stopped in the 1930s to focus on his advertising career.

Watson died in 1958.

• Fast Facts About B.F. SKINNER(1904 – 1990)

Skinner

• Burrhus Fredrick Skinner was born on March 20, 1904, in Susquehanna, Pennsylvania.

• His father was a self-taught lawyer and his mother a housewife.

• As a boy, Skinner showed great mechanical skills by designing a device to separate ripe and green berries and a contraption to remind him to keep his room clean.

• Skinner published his first work “That Pessimistic Fellow,” a poem, in Lone Scout magazine at the age of ten.

Skinner• In 1922, Skinner attended Hamilton College in Clinton, New York.

• After graduating from Hamilton, Skinner decided that he wanted to become a writer and moved back with his parents. Skinner later called this period the “dark year” because he experienced a severe case of writers block.

• During a stay in New York, Skinner happened to read the works of Watson and Pavlov. He was impressed with their work and sought to learn more.

• In 1928, at the age of 24, Skinner applied and was accepted into Harvard’s psychology program.

Skinner

• While at Harvard, Skinner invented Skinner box and the cumulative recorder which made it possible for Skinner to study animal behavior. The cumulative recorder logged the number of bar presses. Skinner noticed that the number of bar presses was dependent on what was received following the bar presses and not the preceding stimulus. Skinner called this behavior, "operant conditioning."

• In 1936, Skinner married Yvonne Blue. They had their first child, Julie, in 1938.

• In 1944, during World War II, Skinner worked on the “Project Pigeon” which trained pigeons to direct bombs by pecking at a target.

Skinner

• In 1943, during Yvonne’s second pregnancy, Skinner designed the “baby tender,” a crib that was designed to be safer than a normal crib.

• In 1945, Skinner became Chair of the Psychology Department at the University of Indiana.

• In 1948, Skinner joined Harvard University’s psychology department.

• Skinner died on August 18, 1990, from leukemia.

Psychology: Pavlov, Watson, Skinner Learning Experiments and Concepts.

Documents