Tricky Topics Video Series Classical Conditioning Classical conditioning, also called Pavlovian conditioning, after its founder Ivan Pavlov, is the focus of this tricky topic. Classical conditioning is one type of associative learning, where an individual makes a connection between two different stimuli or events. More specifically, Classical conditioning occurs when a neutral stimulus becomes associated with a meaningful one, something that triggers an automatic response.
So the types of behaviors involved in classical conditioning are involuntary responses, and psychologists often refer to these as reflexive behaviors. What are some examples of reflexive behaviors? One is pain withdrawal. Say you happen upon this iron, because you need to iron a shirt for a job interview.
Perhaps your roommate left it out for you. How considerate! You reach to grab it and discover it's really hot, so you pull your hand away. That's a reflexive behavior in response to pain.
The next time, just the sight of an iron might automatically trigger an avoidance reaction based upon your past experience. Emotional responses are also involuntary, which is one of the reasons that emotions are often so difficult to control. For instance, If you hear a sudden loud noise, it will probably trigger an automatic startle response, because it provokes fear.
Classical conditioning is all about attaching meaning, so you can predict when things are going to happen, rather than passively react to events. You can't learn about classical conditioning without learning about Ivan Pavlov. He was a Russian physiologist who was awarded the Nobel Prize in Physiology or Medicine in 1904. not for his work on associative learning, but for his research on saliva and digestion.
He measured salivation in dogs when they were given different types of food, like meat powder. He noticed that, over time, the dogs would start drooling before they were given the meat powder, when the technician made noise assembling the equipment to measure their saliva. He hypothesized that the dogs made an association between the noise of preparing the equipment and the food that always followed.
Rather than see this as a nuisance to his digestion research, he decided to investigate further and ask whether the dogs could learn to salivate to other sounds. So this is what he did to test his hypothesis. Before conditioning, he found that the dogs would drool in response to meat, of course, because dogs find meat delicious. This is referred to as the unconditioned stimulus, called the U.S.
And the dog's response is called the unconditioned response, or UR. These are both referred to as unconditioned because this response is reflexive, or unlearned. Before conditioning, a neutral stimulus, such as a non-delicious bell, does not produce salivation. He tested this in the beginning to make sure that dogs don't respond to bells with drooling. This is an example of careful science.
During conditioning, the neutral stimulus is presented just before the US, and as expected, the dog salivates, just as it did when the US was presented alone. If this pairing is repeated enough times, the dog will now salivate when hearing the bell alone, so it has become a conditioned stimulus, or CS, and the dog's response to this new learned cue is called the conditioned response, or CR. Through many, many careful experiments, Pavlov and his research group worked out two fundamental rules of classical conditioning. First, multiple pairings of the US, or natural stimulus, and the CS, or neutral stimulus, are necessary in order for the CS to take on meaning. Second, the CS and US must be presented close together in time, and works best when the CS occurs just before the US, so it can act as a predictor.
Classical conditioning can change once it's established in ways that can tell us something about what is going on in the mind of the learner. For instance, stimulus generalization occurs when stimuli that are similar to the CS will also trigger the learned behavior. Even though these specific stimuli have not been previously paired with the US, it can reveal the types of things an individual finds similar. This is really handy in determining the sensory abilities of individuals who cannot speak, such as animals and babies. Stimulus discrimination training tells us what individuals consider different, and it's the first step in training animals.
Dogs are trained to communicate with us about smells they can detect, like drugs and explosives. It's an amazing collaboration. Without any fancy technology, using just treats, patience, and knowledge of classical conditioning, dogs are able to tell us about dangers that are invisible to us. An organization called Apopole trains African giant pouched rats to clear huge areas of landmines.
They've been called hero rats, and this one shown here was specifically trained to detect the smell of explosives. Their sense of smell is as good or even better than dogs, and because they're smaller they're unlikely to set off hidden mines. Extinction is the disappearance of a CR when the CS and US are no longer paired.
This happens when the CS appears repeatedly on its own, without the meaningful US, and the CR eventually stops happening. So the conditioned response doesn't hang around forever when the conditioned stimulus is presented alone. This figure shows the strength of the CR on the y-axis, what happens during training, and during extinction when the CS is presented alone. When extinction is complete, it's almost as if the learning never happened at all. However, Pavlov showed that if the CS alone is presented after a delay, the CR will spontaneously recover, although the size of the response is usually weaker.
Therefore, it's likely that extinction suppresses learning but does not erase it. Pavlov's findings sparked all sorts of research on classical conditioning. American psychologist John Watson felt so strongly that he set out to test whether classical conditioning could be used to shape human behavior. In his now notorious study of Little Albert in 1920, Watson and colleague Rosemary Rayner conditioned a baby to fear a tame lab rat by presenting it just before a sudden loud noise.
Little Albert learned to fear the rat as well as other fluffy white objects. This showed that his conditioned fear generalized to other stimuli. Little Albert's didn't undergo deconditioning, so this research sparked a lot of ethical controversy.
However, Watson did show that fear can be learned, and many successful treatments for anxiety problems, such as phobias, are based upon unlearning conditioned fear responses. The knowledge of classical conditioning has revealed how our minds link events in a way to act as predictors.