Conditioned stimulus: characteristics and uses in psychology

This concept developed in the behaviorist paradigm is one of the most useful in psychology.

Human beings and other animals are active beings, interacting with an environment on which they depend in order to survive. But why do we do what we do? How do we explain that, for example, when a dog hears a bell it starts salivating or why we run for shelter when we hear an alarm?

This how and why we act the way we act is something that has always been of great scientific interest, and which has been studied and investigated by different theoretical currents in psychology. One of them, behaviorism, considers that it is due to a conditioning process. And within this process, the bell or the alarm would be playing the role of a conditioned stimulus. playing the role of a conditioned stimulus. It is about this concept, that of conditioned stimulus, that we are going to talk throughout this article.

What is a conditioned stimulus?

It receives the name of conditioned stimulus all that element that, being initially neutral and not provoking in the person or animal any reaction by itself, acquires the property of generate a response when associated with another stimulus that does generate a reaction..

Using the example used in the introduction, we react with fear to the sound of an alarm not because the alarm generates a reaction in itself but because we know that this sound is linked to the existence of danger or Pain (the entrance of an intruder, an enemy attack or a fire, for example). In the case of the dog and the bell (part of Pavlov's experiments that gave rise to the study of classical conditioning), the dog will begin to salivate at the sound of the bell because it associates it with the bringing of food (the sound of the bell being a conditioned stimulus).

This relationship is produced by the capacity of association between stimuli, which the most classical conditioning considered specifically proper of the stimulus itself (although nowadays through other currents we know that other aspects such as will, motivation or cognition have an influence).

It is necessary that there be a minimum contingency (i.e., that the appearance of one predicts the appearance of another or that they are presented to a large extent simultaneously or in succession) between the conditioned stimuli and those that have allowed them to become so, the unconditioned stimuli. It is also necessary that the response generated by the latter be strong, and although it is not essential that there be some relationship between the two.

Practically any type of neutral stimulus can become conditioned as long as it is perceptible. The perception can come from any channel or sense, being able to be something visual (lights, an image, etc.), sounds (timbres, voices, concrete words, etc.), tactile perceptions (texture, temperature, pressure), tastes or smells. Even in some cases stimuli that do generate a response can be conditioned if they are paired with stimuli that generate a response that is more relevant to the subject.

Likewise, as we have seen conditioning occurs in a large number of living beings.. It can be observed in humans, but also in dogs, apes, cats, mice or pigeons among many others.

The birth of a conditioned stimulus

Thus, for a conditioned stimulus to exist, there must be something that conditions it: the unconditioned stimulus that by itself generates a response. And the relationship that is established between them is what is called conditioning. The birth of a conditioned stimulus is produced in what is called the acquisition phase (in which it acquires the properties that make it go from being neutral to being conditioned).

From the point of view of classical conditioning, a stimulus is conditioned by another stimulus due to the generation of a link between the appearance of the initially neutral stimulus and the unconditioned stimulus, which in itself generates an appetitive or aversive response (called unconditioned response).

Gradually and as they are presented together or at a short intervalIn this way, the subject makes associations, causing the initially neutral stimulus to acquire appetitive or aversive characteristics and to go from not generating a response to generating the same response as the stimulus that did provoke a response. Thus, a conditioned response will end up being generated and the neutral stimulus will be considered a conditioned stimulus. Henceforth, the appearance of the conditioned stimulus will generate the same reaction as the unconditioned stimulus.

With the possibility of extinction

That a stimulus is conditioned and generates a conditioned response can arise in daily life or be provoked voluntarily, but the fact is that this association will tend to be extinguished if the subject observes that the joint appearance of the unconditioned and conditioned stimulus ceases to occur. Thus, the conditioned stimulus will eventually become neutral again and will no longer generate any responses..

This extinction process can be more or less prolonged depending on several factors.

Among them we find how strong the association between stimuli has been or how many times it has been repeated, or if we have learned that the unconditioned stimulus always appears in all the situations in which the conditioned one appears or a great part of the times (although it may seem counterintuitive, the association takes longer to extinguish if we are used to the fact that both stimuli do not always appear together).

Of course, sometimes it is possible that spontaneous recoveries of the association may appear of the association.

Relationship with psychological problems

There are a large number of behavioral problems that are linked to conditioning, specifically to the fact that a stimulus has become a conditioned stimulus and generates a conditioned response.

In general, the presence of any fear the presence of any fear or even of a phobia can become linked (although a large number of factors come into play and not only these) to this type of association, if a stimulus has been associated with pain or suffering.

Thus, if we were once bitten by a dog, it is possible that we associate any dog with pain, something that will make us fear new exposures and avoid them (the dog being the conditioned stimulus). And not only the fear of phobias but also the fear of post-traumatic stress disorders (for example in people who have suffered a rape may appear fear of sex or people with similar characteristics to the aggressor).

It can also happen the other way around, that we associate something with pleasure or the avoidance of displeasure and excitation or an excessive appetite for this stimulus appears, conditioned. For example, conditioning has been used as an attempt to explain some paraphilias, impulse control disorders, eating disorders or addictions.