The elements or variables of classical conditioning are four: unconditioned stimulus (US), conditioned stimulus (CS), unconditioned response (IR) and conditioned response (CR). Classical conditioning, also called Pavlovian conditioning, responder conditioning, stimulus-response model or association learning (ER), is a type of associative learning that was first demonstrated by Ivan Pavlov.
Unconditioned stimulus (US).
Any stimulus that, prior to the experimental treatment in question, produces a consistent and measurable response. In itself, unconditioned stimuli are those that produce innate reflexes in a strict sense, (but those that consistently produce a response can be used as unconditioned stimuli, previously and independently of the experimental situation in question, although the response is not innate). The unconditioned stimulus must produce the response consistently, that is, uniformly and with a certain intensity or power.
The conditioned stimulus (CS). It is a stimulus that, prior to its pairing with the EI does not produce the conditioned response and, therefore, it is originally a neutral stimulus in relation to said responses. If the conditioned response is originally produced reflexively, it must be of a much lower intensity and quickly extinguished by the repeated presentation of said CS in isolation before beginning the experimental treatment. This reflex response produced spontaneously by the CS is called the alpha response. c) Unconditioned response (IR).
It is the answer that reflexively, measurably and regularly, is produced by the unconditioned stimulus. Gormezano points out that the same IS produces or evokes the reaction of several effector systems, so the unconditioned responses to the same IS can be several. This forces us to clearly define the key that we are going to choose to define the conditioned response.
It is also necessary to distinguish IR from pseudoconditioned or beta responseswhich is a special sensitization of the effector systems that produces the isolated presentation of the US, in such a way that before there is any CS-US association, when a neutral stimulus is presented to the subject, the pseudoconditioned response will be produced spontaneously, due to the special sensitization that the previous isolated presentation of IS has produced.
Conditioned response (CR). It is the response that is learned and is not exactly the same as IR, but only similar. Ordinarily it is a measure of intensity rather than RI. The CR is actually the response that is provoked by the isolated presentation of the CS, once the CS-US connection has been established. The CR has to be clearly specified, defining it as the key response among all the responses of the effector systems excited by the IS.
A good criterion for specifying it is that it must occur in the same effector system as the IR. CR must be distinguished from alpha responses, which are unconditioned responses to the CS in the same effector system in which the conditioned response has been defined. Other Variables There are other variables that influence the associability between the conditioned and unconditioned stimuli, which are different from mere temporal contiguity.
There is the type of unconditioned stimulus that appears and the motivational circumstances of the subject. Also an important variable in the strength with which conditioning occurs is previous experience with the stimuli. Two phenomena that influence conditioning stand out:
- The repeated exposure to an isolated stimulus produces latent inhibition for the conditioning of said stimulus.
- The learned irrelevance It is the effect produced by the pre-exposure of the animal to the conditioned stimulus and the unconditioned stimulus without associating them.