Classical conditioning

Classical conditioning, also called Pavlovlian conditioning, respondent conditioning, stimulus–response model, or associational learning (EE), is a type of associative learning that was first demonstrated by Ivan Pavlov. This author devised some experiments with dogs that are the basis of classical conditioning. He noticed that when he put the food on the dog, it salivated. Every time he put food on it, Pavlov would ring a bell, so that when the dog heard it, he would associate that sound with food and salivate. Thus, the dog was making a response (in this case, salivation) to a stimulus (the bell). The next time he heard the bell, regardless of whether it was attached to the food, he would begin to salivate.

The simplest form of classical conditioning recalls what Aristotle would call the law of contiguity. In essence, the philosopher said "When two things usually occur together, the appearance of one will bring the other to mind." Despite the fact that the law of contiguity is one of the main axioms of classical conditioning theory, the explanation of the phenomenon given by these theorists differs radically from that exposed by Aristotle, since they place special emphasis on not making any allusion to concepts as "mind". That is, all those concepts that are not measurable, quantifiable and directly observable. Furthermore, it is more accurate to state that more than mere temporal contiguity, it is the dependency relationship between the presentation between the first and the second stimulus that sets the conditions in which conditioning occurs.

In -------> Rn

EI -------> RI

Both lines of the schematic show unconditional or unlearned relationships. The first represents the relationship between a stimulus, which although it evokes the typical response of the species to it (for example, orienting itself towards the source of a sound), we can consider as neutral with respect to the response we are trying to condition (for example, salivation) . The second line represents the natural, unlearned or unconditioned relationship between another stimulus (US = Unconditioned or natural stimulus) and the response to it (RI = Unconditioned or natural response). Dogs naturally salivate (RI) in the presence of food (EI).

EC -------> RC

EI -------> RI

However, by virtue of the dependency relationship that is established between the presentation of both stimuli, so that one functions consistently as a condition for the presence of another, it is possible that another stimulus also evokes IR, although it did not do so before. did. For example, the presence of the sound of a bell a few seconds before the presentation of food: after a few trials, the sound of the bell alone would reliably evoke the salivation response, in addition to continuing to evoke the orientation response. before the sound. The bell now functions as a conditioned stimulus that produces a conditioned response.. The proof that the conditioning has been carried out consists in presenting only the conditioned stimulus (CS), without the unconditioned stimulus (US), observing that the conditioned response (CR) is produced consistently, as long as it continues to be presented. , albeit occasionally, the presentation of the unconditioned stimulus after the conditioned stimulus.

EC -------> RC

The original and most famous example of classical conditioning involved Pavlov's salivary conditioning of dogs. During his investigations of the physiology of digestion in dogs, Pavlov noticed that instead of simply salivating when presented with a ration of powdered meat (an innate response to food that he called the unconditioned response), dogs began to salivate immediately. presence of the lab technician who normally fed them. Pavlov called these psychic secretions. From this observation, he predicted that if a particular stimulus was present when the dog was given its food ration, then this stimulus would become associated with the food and cause salivation of its own. In his initial experiment, Pavlov used a metronome (at 100 beats per minute, although it is popularly believed that he used a bell) to call the dogs to eat, and, after several repetitions, the dogs began to salivate in response to the metronome ( device used by musicians to mark the rhythm).

Associated Phenomena

The persistence of the conditioned reflex depends on the concurrent presentation of its elements. If the US stops presenting after the CS, the CR finally disappears, a phenomenon known as extinction . After this process has been completed, the conditioned response could reappear without the elements being presented together again, which is known as spontaneous recovery . Finally, the conditioned response is no longer presented to the conditioned stimulus, so that with respect to it it functions again as a neutral stimulus (NE).

EC -------> Not RC

Namely:

In -------> Rn

The formal properties of stimuli can play an important role in the process of classical conditioning. CR can appear in the presence of stimuli that were not originally CS, but share some characteristics with them. For example, if the CS is a bell sound, the CR could also appear to a doorbell, a clock ticking, or other noises, which is known as stimulus generalization . The opposite phenomenon, by which the conditional response is produced in response to stimuli with increasingly specific characteristics, is known as stimulus discrimination.. A classic experiment of this phenomenon describes how pigeons were trained to respond to exposure to a certain frequency of sound, being able to omit the response to minimal variations in this frequency.

A CS can sometimes function as a US in a conditioning process, so that a new neutral stimulus can function as a CS (CS2) by associating with a first CS (CS1):IE ----------> fI|EC1 ---------> fC|EC2 ---------> fC

This phenomenon is known as second-order conditioning . Apparently, cases of conditioning up to the third order have been documented, but they are very difficult to achieve and maintain.

Empirical evidence in humans

Studies of classical conditioning in humans have sparked much controversy regarding the extent to which the conclusions obtained in experiments with other animals are generalizable to humans. John B. Watson and Rosalie Rayner showed that the Pavlovian conditioning process could be used in humans and was probably an important source of our experience, in what has been called the Little Albert experiment. In more recent times, classical conditioning processes have been identified in humans such as:

• Taste aversive conditioning.
• Conditional nausea (in chemotherapy, for example).
• Blink or palpebral conditioning.
• Patellar reflex conditioning.
• Phobias.

Classical inhibitory conditioning

You learn to retain or inhibit the conditioned response. An inhibitory stimulus (conditioned stimulus) signals the absence of the unconditioned stimulus, so the conditioned response is inhibited .

Second Order Conditioning

It is a form of acquisition in which a new neutral stimulus can become a conditioned stimulus, if it is associated with a conditioned stimulus.

For example, in Pavlov's conditioning of salivation, if a light is associated with sound, over time the light itself can also trigger the salivation response, although with less intensity.

It is a conditioning that occurs in the acquisition of phobias. For example, if something scares us a lot, due to previous conditioning (plane, dog, incident...), a sound, an aroma or a vision that is associated with that situation will cause concern and fear, although not as intense.