Pavlov’s experiments with dogs are very well-known in the science history. They formed a foundation for the concept of CONDITIONING, which is now a significant method in behavioral research and applied areas which adopt behaviorism.
The discovery occurred in the course of Pavlov’s examinations about dog’s reflex actions, such as drooling at food. Pavlov noticed that there were times the dog drooled just as he entered the room, even without any food presented.
Image 1. A simplified visualization of Pavlov’s conditioning experiment using the sound of the tuning fork as the CS. a) Food was fed, to familiarize the dog with it. b) Food was presented, to ensure its sight evoked the UR (salivation). c) Food was presented to the dog, while the tuning fork was struck. UR occurred. This combined acts were repeated several times. d) The tuning fork was struck without the food presented. UR occurred. Conditioning was achieved. e) After several repetitions of (d), the dog no longer salivated at the sound. Extinction was achieved.
To investigate the phenomenon, Pavlov brought food to the dog while at the same time presenting a factor which the dog did not particularly respond at (eg. a light, the sound of a tuning fork…). After several repetitions of this combination, at one point Pavlov presented only the additional factor, and the dog drooled at it as well. This process was defined by Pavlov as conditioning. The food was called an unconditional stimulus (US), the salivation at the food an unconditional response (UR), the additional factor an conditional/conditioned stimulus (CS), the dog’s original attitude at the CS an neutral response (NR), and the salivation at the mere presentation of the CS a conditioned response (CR).
The basic procedure of Pavlov’s conditioning can be formulated as followed:
It was noticed that, at a later point following repetitions of Step (3), the dog stopped drooling at the sound, resuming its NR at the CS. This phenomenon is termed extinction.
Pavlov’s conditioning process is now called classical conditioning, as distinguished from the operant conditioning coined and demonstrated by Skinner (see I.5).
2. PUZZLE BOX (Thorndike, 1898)
Puzzle Box was an instrument designed by Thorndike for studying learning in animals, namely cats and dogs. The box was built as a cage with a simple locking mechanism (see Image 2).
Image 2. A simplified visualization of the Puzzle Box based on Thorndike’s model (1898).
Image 3. A simplified visualization of Thorndike’s Puzzle Box Study on a Cat. a) A fish was used to tempt the cat into escape. b) The cat pushed the bar, unlocking the gate on its side. c) The cat pulled the string, unlocking the gate on its top. d) The cat pushed down the gate and escaped the box.
The test animal was to be locked in the box, while a tempting piece of food was presented to it beyond its reach. While trying to get out of the box for food, the animal would accidentally remove the locks. After every escape, the animal was awarded the food and then placed into the cage again for another attempt. According to Thorndike’s report (1898), the amount of time it took for the animal to escape gradually decreased and the movements the animal made tended to be more focused over attempts, suggesting that the animal actually learned how to get out of the cage by and by.
3. LAW OF EXERCISE & LAW OF EFFECT (Thorndike, 1905; Thorndike, 1912)
Drawing from his studies of animal learning, Thorndike introduced the two laws for habit formation in the learning process, Law of Exercise and Law of Effect.
In simple words, the Law of Exercise states that, the more repetitively or strongly a behavior is connected to a situation, the more likely that behavior is to be performed in response to the same situation in the future. Rather common sense to us, this law refers to practice in learning. Take the animal’s improvement in unlocking the Puzzle Box by Thorndike (1898) over many attempts as an example: the animal was familiarized with movements that linked more consistently to the escape, and concentrated on such movements in later attempts, which led to its being quicker and quicker in escaping.
The Law of Effect, meanwhile, refers to consequences: the more satisfying a consequence associated with a behavior is, the more likely that behavior is to be performed again; likewise, the more dissatisfying a consequence associated with a behavior is, the more unlikely that behavior is to be performed again. Briefly speaking, pleasant consequences to a behavior encourage it, while unpleasant ones discourage it. This law was reflected in Thorndike’s studies with cats (1898) as in how the animals stopped making ineffective movements for escape, such as trying to squeeze themselves through the gap between the bars, after these movements left them frustrated. As emphasized by Thorndike (1912), Law of Effect is significant in education as a fundamental principle for building desired habits and eliminating undesired behaviors.
Image 4. A simplified visualization of Watson and Rayner’s Little Albert Experiment a) The rat was presented to Little Albert. b) As the baby moved to touch the rat, the loud noise was made. c) The baby jumped and hid his face into the mattress. d) The repeated combination of the rat and noise eventually made Albert cry. e) At one point, the baby cried at the mere sight of the rat.
联系客服
