BY: Yakkun

PAVLOV’S DOGS

General theory

Classical Conditioning – It is a type of mental conditioning, which associates a

previously neutral stimulus, with an unconditioned stimulus to elicit the desired

response. It simply means to link a neutral, unrelated stimulus, to another

unconditioned stimulus to create a response that originally should not be created. A

conditioned stimulus is paired with an unconditioned stimulus. After pairing is

repeated, the organism will exhibit a conditioned response to the conditioned stimulus,

when only the conditioned stimulus is demonstrated. Classical conditioning became the

basis for a theory of how organisms learn, and a philosophy of psychology developed by

John B. Watson, B.F. Skinner and others.

Hypothesis

The conductor of this experiment, Russian physiologist Ivan Pavlov was looking

at salivation in dogs in response to being fed. He then soon noticed that the dogs

salivated whenever he entered the room, even he was not willing to feed the dogs. Pavlov

started from the idea that dogs learned things that they didn’t need to learn. The reflex

of salivation was hardwired into the dog. So, he decided to conduct an experiment

involving dogs with food. His hypothesis was that dogs will respond to a neutral

stimulus, with a conditioned response. He used the sound of the bell, as a neutral

stimulus, linking it with the other stimulus, which is the food.

Experiment Overview

In this experiment, Pavlov used a bell as his neutral stimulus. Whenever he feed the

dogs, he always rang a bell. After repeating this procedure many number of times, he

went into the room, and only rang the bell without bringing the food. Like expected,

dog’s salivation level increased when Pavlov rang the bell. The dog had learned an

association between the bell and the food and developed a new behavior. Because this

response was conditioned to learn, it is known as the conditioned response. The neutral

stimulus has become a conditioned stimulus.

Illustration of Hypothesis

UCS – Unconditioned stimuli

UCR – Unconditioned response

CS – conditioned stimuli

CR – conditioned response

How the sample was selected

The sample, which was the dog was selected because the conductor Ivan Pavlov

was looking at a dog when he first came upon to conducting this experiment. When he

saw the dog salivate only because he walked in the room.

The population from which the sample was selected

Pavlov wasn’t picky about the types of dogs he used as the sample of this

experiment. He didn’t go for a specific breed, but instead seem to have used all types of

dogs, many of them mutts. The picture below is the dogs Pavlov used for his experiment.

All are from differing in breed.

How the sample was divided into experimental and control groups

The dogs were divided into experimental and control groups by either

conditioning the unconditioned stimuli with the conditioned stimuli or not. In this

experiment, the unconditioned stimuli was the food, and the conditioned stimuli was

the bell. To see the difference in the two, one group must be conditioned to react, and

the other shouldn’t be.

Sample Selection & Assignment to Experimental and Control Groups

The type of dogs Pavlov chose for his experiment:

Assignment to the experimental Group

Independent Variable

The independent variable of this experiment was the conditioned stimulus being

used, in this case the bell ringing. Because the independent variable must be

independent, in other words not dependent on the other variable, it is the bell. The bell

will functions either the other variable will react or not. Because the dogs are being

conditioned to react to the bell, without it this experiment will not work.

Dependent Variable

The dependent variable was whether the dog salivated or not. It is measuring the

dog’s responsiveness to the independent variable, which is the bell. The salivation will

be the dependent variable because it is completely dependent on the independent

variable, which is the bell. Because the dog is conditioned to show response to the bell,

without it there will not be any salivation happening in the dog’s mouth.

Results of the experiment

When Pavlov went into the room without the food and rang only the bell, the

dog’s salivation level increased. Even though he didn’t feed the dog, the dog reacted in

the increase of salivation level. Pavlov succeeded in linking the neutral stimulus, which

is the bell and the conditioned response, which is the salivation. Pavlov found that for

the associations to be made, the two stimuli must occur closely in time. He called this

the law of temporal contiguity.

Illustration of how the IV (Independent Variable) varied from the

experimental to the control group

The independent variable did not vary from the experimental to the control

group, because it is the bell. No matter if the dog shows response to the bell, the bell

itself will always function properly, thus independent variable does not vary from the

experimental to the control group.

Illustration of how the DV (Dependent Variable) varied from the

experimental to the control group

For the control group, the dog will always show no response to the bell, because it is not

paired with it. For the experimental group, the dog will show an increased level of

salivation as response because it is paired with the conditioned stimulus which is the

bell. Therefore the dependent variable will not occur for the control group, but for the

experimental group, it will occur because the bell is paired with the salivation.

Difference between the Experimental and the Control Group

Researchers decided either whether or not the difference between the

experimental and the control group was significant by looking at the dog’s salivation

level. They determine the difference between the two groups being significant, by

comparing the response of the dog, which is whether there is an increase in the

salivation level. If there is a significant difference in salivation level between the control

and the experimental group, the difference can be considered as significant.

Conditions that have affected the difference between the Experimental and

Control Groups

There are few conditions that could have affected the difference between the

experimental and control groups in Pavlov’s Dogs.

Ethical Considerations

In Pavlov’s experiment, none of the dogs was physically harmed, so in that terms

this experiment can be considered ethical. But, pairing the dog’s unconditioned

response with a neutral stimulus might be considered to be unethical. Because of this

two being paired, the dog will subconsciously show the response of salivation to the bell,

even though there are no signs of food appearing. But, apart from that there weren’t any

significant ethical problems in this experiment.

Practical applications

This experiment made classical conditioning famous. Classical conditioning

became the basis for how organisms learn. Pavlov played a huge role in making this

happen. He had a great impact on the field of physiology by publishing this research.

For his original work in the field of research, Pavlov was awarded the Nobel Prize in

Physiology or Medicine in 1904. Ivan Pavlov is referred to as the father of classical

conditioning, after his major contribution to this mental type of conditioning.

Copy of the article describing the research

Pavlov’s Dogs | Simply Psychology

By Saul McLeod published 2007, updated 2013

Like many great scientific advances, classical conditioning was discovered accidentally.

During the 1890s Russian physiologist Ivan Pavlov was looking at salivation in dogs in

response to being fed, when he noticed that his dogs would begin to salivate whenever

he entered the room, even when he was not bringing them food. At first this was

something of a nuisance (not to mention messy!).

Pavlovian conditioning

Pavlov (1902) started from the idea that there are some things that a dog does not need

to learn. For example, dogs don’t learn to salivate whenever they see food. This reflex is

‘hard wired’ into the dog. In behaviorist terms, it is an unconditioned response (i.e. a

stimulus-response connection that required no learning). In behaviorist terms, we write:

Unconditioned Stimulus (Food) > Unconditioned Response (Salivate)

Pavlov showed the existence of the unconditioned response by presenting a dog with a

bowl of food and the measuring its salivary secretions (see image below).

However, when Pavlov discovered that any object or event which the dogs learnt

to associate with food (such as the lab assistant) would trigger the same response, he

realized that he had made an important scientific discovery. Accordingly, he devoted the

rest of his career to studying this type of learning.

Pavlov knew that somehow, the dogs in his lab had learned to associate food with his lab

assistant. This must have been learned, because at one point the dogs did not do it, and

there came a point where they started, so their behavior had changed. A change in

behavior of this type must be the result of learning.

In behaviorist terms, the lab assistant was originally a neutral stimulus. It is called

neutral because it produces no response. What had happened was that the neutral

stimulus (the lab assistant) had become associated with an unconditioned stimulus

(food).

In his experiment, Pavlov used a bell as his neutral stimulus. Whenever he gave food to

his dogs, he also rang a bell. After a number of repeats of this procedure, he tried the

bell on its own. As you might expect, the bell on its own now caused an increase in

salivation.

So the dog had learned an association between the bell and the food and a new behavior

had been learnt. Because this response was learned (or conditioned), it is called a

conditioned response. The neutral stimulus has become a conditioned stimulus.

Pavlov found that for associations to be made, the two stimuli had to be presented close

together in time. He called this the law of temporal contiguity. If the time between the

conditioned stimulus (bell) and unconditioned stimulus (food) is too great, then

learning will not occur.

Pavlov and his studies of classical conditioning have become famous since his early work

between 1890-1930. Classical conditioning is "classical" in that it is the first systematic

study of basic laws of learning / conditioning.

Summary

To summarize, classical conditioning (later developed by John Watson) involves

learning to associate an unconditioned stimulus that already brings about a particular

response (i.e. a reflex) with a new (conditioned) stimulus, so that the new stimulus

brings about the same response.

Pavlov developed some rather unfriendly technical terms to describe this process. The

unconditioned stimulus (or UCS) is the object or event that originally produces the

reflexive / natural response.

The response to this is called the unconditioned response (or UCR). The neutral

stimulus (NS) is a new stimulus that does not produce a response.

Once the neutral stimulus has become associated with the unconditioned stimulus, it

becomes a conditioned stimulus (CS). The conditioned response (CR) is the response to

the conditioned stimulus.

Bibliography

- Classical conditioning. (2009, November 12). Retrieved October 14, 2014, from

http://en.wikipedia.org/wiki/Classical_conditioning

- Boyd, N. (n.d.). Ivan Pavlov and Classical Conditioning: Theory, Experiments & Contributions

to Psychology. Retrieved October 15, 2014, from http://education-

portal.com/academy/lesson/ivan-pavlov-and-classical-conditioning-theory-experiments-

contributions-to-psychology.html

- McLeod, S. (2007, January 1). Pavlov's Dogs. Retrieved October 15, 2014, from

http://education-portal.com/academy/lesson/classical-conditioning.html

- Ivan Pavlov. (n.d.). Retrieved October 15, 2014, from http://en.wikipedia.org/wiki/Ivan_Pavlov

- Cherry, K. (n.d.). Pavlov's Dogs & the Discovery of Classical Conditioning. Retrieved

October 16, 2014, from http://psychology.about.com/od/classicalconditioning/a/pavlovs-

dogs.htm

- Pavlov's Dog. (n.d.). Retrieved October 17, 2014, from

http://www.nobelprize.org/educational/medicine/pavlov/