How Does Classical Conditioning Work?
Classical Conditioning is the method of teaching connections between two stimuli. It is the process of associating, and consequently, providing meaning to a neutral stimulus with another meaningful stimulus, in order to elicit similar response. For example, we cover our ears when lightning strikes. This is because we have learned through classical conditioning that thunder occurs after the strike of lightning. We incorporate the meaning of thunder to lightning, such that we elicit the same behavior (covering of ears) we attribute to thunder.
Classical conditioning makes use of our reflexes to teach associations. Almost all of us exhibit the same reflexes upon birth, although some fade in time. Reflexes are automatic stimulus-response connections, such as when we salivate with food, we feel nauseated with spoiled food, we shiver in response to low temperature, we cough with clogged throat, our pupils constrict in response to bright light, and we withdraw from blows and burns. Because reflex responses are automatic, they are almost always involuntary. Using the example posed earlier, we have learned to cover our ears when lightning strikes because that is our automatic response to loud sounds. Through classical conditioning, we have learned to transfer this response from thunder to lightning as well.
Basic Processes of Classical Conditioning
Classical conditioning works like this: A neutral stimulus is paired with a meaningful stimulus (the reflex stimulus), until the neutral stimulus gains the meaning of the other stimulus. The neutral stimulus then becomes a conditioned stimulus, and the original automatic response (the reflex response) from the original meaningful stimulus is transferred to the neutral stimulus and becomes the conditioned response. From the example above, the meaningful stimulus is thunder, and the automatic response to that sitmulus is "covering of ears". Through continued pairing with thunder, lightning, which was originally a neutral stimulus, acquires the meaning of thunder and becomes a conditioned stimulus. Consequently, we elicit similar response to ligthning, so that "covering of ears" becomes a conditioned response. Thus, we no longer just cover our ears in response to loud sounds (like thunder), but also to lightning.
- Acquisition. Acquisition is the initial learning of the stimulus-response link. Two important aspects of acquisition are contiguity and contingency. Continguity is the time interval between the occurrence of the meaningful stimulus and the neutral stimulus. The optimal time interval between the two stimuli is 0.25 second. Contingency, on the other hand, is the predictability between the two stimuli (Roscoria, 1966 & 1988). Ideally, the two stimuli should always be paired together until acquisition occurs. For example, if thunder doesn't always come after lightning, we would never learn to cover our ears when lightning strikes. Learning through classical conditioning doesn't take much time. If we plot the number of times we exhibit the same response to the neutral stimulus as tha pairing goes, we would come up with a half-parabola. (A half-parabola looks like the left half of a hill.) This means that we learn quite easily with classical conditioning. To demonstrate how fast we learn with classical conditioning, imagine the first time you heard the kettle whistle. It probably took you less than 3 trials to know that the water started to boil.
- Generalization and/or Discrimination. Generalization is the application of learning to other similar stimuli. Using the thunder -lightning example, if you are watching a movies, and lightning striked in the movie, you would probably expect to hear thunder to follow. Discrimination, on the other hand, is the process of knowing when not to elicit similar response. Using the example of the whistling kettle above, if a family member blows a whistle while you're heating kettle on the stove, you would probably know that the whistle is not coming from the kettle and water is not yet boiling, because the sound of the kettle whistle is not the same as the one your family member just blew. The process of generalization and discrimination is important in learning. For example, herbivores should be able to distinguish edible plants from poisonous ones. Similarly, educators use this process to check if students understand the concepts taught in class. Multiple-choice questions are oftentimes used to evaluate how a student can discriminate one concept from another.
- Extinction. Extinction is the process of unlearning the conditioned stimulus. The philosophy behind acquisition and extinction is this: "If it can be learned, it can also be unlearned." Extinction occurs with the absence of the unconditioned or originally meaningful stimulus. With extinction, the conditioned response weakens. If we plot the number of times we exhibit the conditioned response to the conditioned stimulus when the unconditioned stimulus is absent, we would come up with a half hyperbola. (A half-hyperbola looks like the right half of a volcano.)
- Spontaneous Recovery. Unlike acquisition, unlearning a conditioned stimulus takes time. To demonstrate our difficulty to unlearn, spontaneous recovery is the recurrence of the conditioned response despite continued absence of the conditioned stimulus after a period of rest. If we continue to plot following extinction, spontaneous recovery is a smaller half-hyperbola after a period of no response. The good thing is that spontaneous recovery quickly dies out, and the negative hyperbola gets even smaller in time.
Origin of Classical Conditioning
Classical conditioning originated from the experiments of the Russian physiologist Ivan Pavlov. He first observed that dogs salivate in response to multiple stimuli - meat powder, sight of the food dish, sight of the individual who brings the food, and the sound of the door closing upon the arrival of food. He realized that the dogs' association between food and these stimuli is an important learning process. In order to uncover the process of associating food with these stimuli, Pavlov conducted an experiment. In 1927, Pavlov taught the dogs to salivate in response to the ringing of a bell. After only a few trials of pairing the bell with the arrival of food, the dogs easily learned to salivate in response to the ringing bell. He found that the dogs also salivate in response to similar sounds of ringing, but not to others, and that the dogs had trouble unlearning this association due to high incident of observed spontaneous recovery. Pavlov successfully demonstrated his work to the students of the Military Medical Academy in Russia.
Benefits and Application of Classical Conditioning
- Explaining and Eliminating Fear. Santrock (2003) explains that the possible reason why only a few children in Sweden and Norway develop high level of dental fear (3-4% compared to 20% of US children) is the Universal Health Care System offered in those countries. Because Swedish and Norweigian children go on a regular basis, and not only when they have dental problem, there is lack of contingency to support association between the dental clinic and painful dental treatment. Fear can also be induced. After only 7 pairings between a white rat and loud noise, John Watson and Rosalie Rayner (1920) taught 11-month old Albert to fear the white rat. Albert also generalized his fear with white rabbits, dogs and sealskin coats. Fear can also be reversed and unlearned. Counterconditioning is the process of weakening a conditioned response by continually pairing the conditioned stimulus (or the object of fear) to a neutral stimulus that elicit a response incompatible with the conditioned response (or fear). Mary Cover James (1924) successfuly removed 3-year old Peter's fear over white rats, fur coats, frogs and fish, after slowly pairing a similar conditioned stimulus (a white rabbit) with food (crackers and milk). At first, the rabbit was placed far enough to prevent Peter from getting upset, then it was moved nearer and nearer every day until Peter was actually petting the white rabbit while eating.
- Explaining Pleasant Emotions. We oftentimes develop attachment over certain places and things because we've had history of explaining pleasant situations with them. Remember the time you broke with your boyfriend/girlfriend and found comfort with the things he/she gave you? Or the moment you returned to your home town and felt overwhelmed with joy because you remember those childhood memories? Our objects of attachment result from the good things we associate with them. They may be common or deviant. Fetish over undergarments and shoes, for example, may have developed at a young age.
- Explaining Health Problems. Work stress may be due to classical conditioning. A boss's criticism or a fight with a co-worker could induce physiologic responses, such as muscle tension, headache and high blood pressure. Imagine if these work scenarios happen on a daily basis. Developing association between work and the above-mentioned physiologic responses could lead to long-term work stress, and possibly the development of chronic diseases, such as heart ailments and respiratory problems. Deaths from drug overdose may also be due to classical conditioning. Most deaths in heroin use happen when the drug is taken outside a familiar setting, like on a different time or place. This is because the body takes its cue from the context in which the drug is usually taken and anticipates the drug, thereby lessening its effects. Taking the drug in unusual circumstances causes the body to get shocked and react dangerously. Immunosuppression, or the shutting down of the immune system due to decreased production of antibodies, may also be induced by classical conditioning. Ader (1974) unexpectedly killed the rats in the second month of his study after repeatedly pairing cytoxan with sweet water (saccharin solution). He was originally observing the rate of extinction of their association when the rats died. He found soon after that cytoxan not only causes nausea, but also immunosuppression, and that these unconditioned responses were transferred with repeated pairing of sweet water. Thus, the rats' bodies learned to shut down their immune system with continued introduction of the sweet water.
- Consumer Psychology. Consumer Psychology is the study of how consumers think, feel, reason and select between different brands and product alternatives. Research on classical conditioning and consumer psychology suggests to use classical conditioning on advertisements only to infrequently encountered products and branding, and that the conditioned stimulus should always precede the unconditioned stimulus (unlike the common setting in classical conditioning where the CS follows the UCS).