Even if you are new to the study of psychology, chances are that you have heard of Pavlov and his famous dogs. Pavlov — , a Russian scientist, performed extensive research on dogs and is best known for his experiments in classical conditioning Figure 1. As we discussed briefly in the previous section, classical conditioning is a process by which we learn to associate stimuli and, consequently, to anticipate events.
Figure 1. Pavlov came to his conclusions about how learning occurs completely by accident. Pavlov was a physiologist, not a psychologist. Physiologists study the life processes of organisms, from the molecular level to the level of cells, organ systems, and entire organisms. In his studies with dogs, Pavlov measured the amount of saliva produced in response to various foods.
Salivating to food in the mouth is reflexive, so no learning is involved. To explore this phenomenon in an objective manner, Pavlov designed a series of carefully controlled experiments to see which stimuli would cause the dogs to salivate. He was able to train the dogs to salivate in response to stimuli that clearly had nothing to do with food, such as the sound of a bell, a light, and a touch on the leg. Through his experiments, Pavlov realized that an organism has two types of responses to its environment: 1 unconditioned unlearned responses, or reflexes, and 2 conditioned learned responses.
The meat powder in this situation was an unconditioned stimulus UCS : a stimulus that elicits a reflexive response in an organism. In classical conditioning, a neutral stimulus is presented immediately before an unconditioned stimulus. Pavlov would sound a tone like ringing a bell and then give the dogs the meat powder Figure 2. The tone was the neutral stimulus NS , which is a stimulus that does not naturally elicit a response. Prior to conditioning, the dogs did not salivate when they just heard the tone because the tone had no association for the dogs.
Quite simply this pairing means:. When Pavlov paired the tone with the meat powder over and over again, the previously neutral stimulus the tone also began to elicit salivation from the dogs. Thus, the neutral stimulus became the conditioned stimulus CS , which is a stimulus that elicits a response after repeatedly being paired with an unconditioned stimulus. The behavior caused by the conditioned stimulus is called the conditioned response CR.
Figure 2. Before conditioning, an unconditioned stimulus food produces an unconditioned response salivation , and a neutral stimulus bell does not produce a response. During conditioning, the unconditioned stimulus food is presented repeatedly just after the presentation of the neutral stimulus bell. After conditioning, the neutral stimulus alone produces a conditioned response salivation , thus becoming a conditioned stimulus.
Stimulus-based control of behavior occurs when the presence or absence of an Sd or S-delta controls the performance of a particular behavior. The presence of a discriminative stimulus causes a behavior to occur.
Stimulus discrimination training may also occur with punishment. A behavior is less likely to occur in the presence of the SD. A behavior is more likely to occur in the presence of the S-Delta. Stimulus control can be defined as a change in rate, latency, duration, or amplitude of the response in the presence of specific stimuli.
Begin typing your search term above and press enter to search. Press ESC to cancel. Social studies. Ben Davis June 27, What is CS in stimulus discrimination? What causes stimulus discrimination? What does SD mean in behavior? What is needed for stimulus control? What is stimulus equivalence ABA? What are stimulus equivalence procedures? Previous Article What do you say in a Thanksgiving speech?
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What is CS and US in psychology? What is CS and CR in psychology? Why do we distinguish between CR and UR? What does CR mean in psychology? For classical conditioning to be effective, the conditioned stimulus should occur before the unconditioned stimulus, rather than after it, or during the same time. Thus, the conditioned stimulus acts as a type of signal or cue for the unconditioned stimulus.
Often during this stage, the UCS must be associated with the CS on a number of occasions, or trials, for learning to take place. However, one trail learning can happen on certain occasions when it is not necessary for an association to be strengthened over time such as being sick after food poisoning or drinking too much alcohol. They did this in what is now considered to be one of the most ethically dubious experiments ever conducted — the case of Little Albert.
Albert B. When he was about nine months old, his reactions to various stimuli including a white rat, burning newspapers and a hammer striking a four-foot steel bar just behind his head were tested. Only the last of these frightened him, so this was designated the unconditioned stimulus UCS and fear the unconditioned response UCR.
The other stimuli were neutral because they did not produce fear. When Albert was just over eleven months old, the rat and the UCS were presented together: as Albert reached out to stroke the animal, Watson struck the bar behind his head.
This occurred seven times in total over the next seven weeks. By this time the rat, the conditioned stimulus CS , on its own frightened Albert, and fear was now a conditioned response CR. The CR transferred spontaneously to the rabbit, the dog and other stimuli that had been previously neutral. Five days after conditioning, the CR produced by the rat persisted. The implications of classical conditioning in the classroom are less important than those of operant conditioning , but there is a still need for teachers to try to make sure that students associate positive emotional experiences with learning.
If a student associates negative emotional experiences with school, then this can obviously have bad results, such as creating a school phobia. For example, if a student is bullied at school they may learn to associate the school with fear. It could also explain why some students show a particular dislike of certain subjects that continue throughout their academic career.
This could happen if a student is humiliated or punished in class by a teacher. Classical conditioning emphasizes the importance of learning from the environment, and supports nurture over nature. However, it is limiting to describe behavior solely in terms of either nature or nurture , and attempts to do this underestimate the complexity of human behavior. It is more likely that behavior is due to an interaction between nature biology and nurture environment.
The process of classical conditioning can probably account for aspects of certain other mental disorders. For example, in post-traumatic stress disorder PTSD sufferers tend to show classically conditioned responses to stimuli present at the time of the traumatising event Charney et al. There have been many laboratory demonstrations of human participants acquiring behavior through the process of classical conditioning. It is relatively easy to classically condition and extinguish conditioned responses, such as the eye-blink and galvanic skin responses.
However, applying classical conditioning to our understanding of complex human behavior such as memory, thinking, reasoning or problem-solving has proved more problematic. In normal adults the conditioning process can apparently be overridden by instructions: simply telling participants that the unconditioned stimulus will not occur causes an instant loss of the conditioned response, which would otherwise extinguish only slowly Davey, There are also important differences between very young children or those with severe learning difficulties and older children and adults regarding their behavior in a variety of operant conditioning and discrimination learning experiments.
This suggests that people have rather more efficient, language-based forms of learning at their disposal than just the laborious formation of associations between a conditioned stimulus and unconditioned stimulus. Even behavior therapy, one of the apparently more successful applications of conditioning principles to human behavior, has given way to cognitive— behavior therapy Mackintosh, A strength of classical conditioning theory is that it is scientific. This is because it's based on empirical evidence carried out by controlled experiments.
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