Simply put, they are those things or situations that have the capacity to make us respond without deliberation. Could we include the mother-in-law in this definition? Now we shall see…
We are surrounded by signals that provoke a reflex or automatic response in us, i.e. unconditioned: it generates a change in physiological reaction every time it appears under certain conditions.
Under normal circumstances, some are capable of causing a reflex response every time, e.g. light constricts the pupil, every time (leaving aside exceptions including substance use or situations where a vasodilator has been applied, etc.).
In others, however, the response does not always occur: the smell of our favourite food does not generate salivation if we are full, for example.
If we move into classical conditioning, we speak of aversive and appetitive stimuli, i.e. when an aversive or avoidant response is generated (the harm done when we touch a hot pot in which spaghetti is boiling, for example, to make spaghetti bolognese with a spicy kick).
But other times they can be appetitive stimuli if the response is positive or pleasant, as when fresh water relieves our thirst after walking 50 kilometres at a fast pace and without previous training, provoking in our body a sensation of pleasure.
Let’s think, for a moment, of that food that automatically makes us salivate. Or the smell of rotten eggs and the response of disgust and nausea it generates in us. Or looking at a light bulb and the involuntary pupillary contraction. And the dread we hear when we hear a sudden loud sound?
The difference between a neutral stimulus and an unconditioned stimulus is that the former does not generate any response unless it is linked to the unconditioned stimulus, and the neutral stimulus does require an associative learning process.
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For a neutral stimulus to be associated with an unconditioned stimulus, two requirements are necessary: proximity and repetition. In this way, neutral stimulation acquires the power to elicit responses that unconditioned signals have .
First, the neutral element must be present along with the unconditioned. We see this with Pavlov’s experiment, where the sound of the bell (neutral) appears together with the food (unconditioned).
If the stimuli are presented together, but the scene is not repeated several times, association is not possible. Learning requires repetition, and therefore the situation in which the two appear must be replicated over and over again until the bond develops and strengthens .
The difference between conditioned and unconditioned signals is that the latter do not need other motivations to take effect. On the other hand, conditioned signals result from pairing a neutral stimulus with an unconditioned stimulus, and the neutral stimulus, which previously produced no response, acquires the capacity to generate the same reaction and elicits the unconditioned stimulus, ceasing to be neutral and acquiring a conditional character .
We can say that one stimulus is innate, and the other is acquired by association. Despite this difference, both have the potential to produce the same response.
Where do we place instinct in all this mumbo-jumbo? Remember that of all stimuli, unconditioned stimuli are the most familiar because they make us react instinctively, reflexively or involuntarily: they do not need us to think to generate an organic response.
📎 Alcaine, A. [Albert]. (2024, 17 September). What is unconditioned stimulus?. PsicoPop. https://www.psicopop.top/en/what-is-unconditioned-stimulus/
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