Human beings, although we are members of the same species and we look alike in many ways, also have great individual differences from each other. Sensory thresholds play a fundamental role in these differences , as they are the limits that each person has to tolerate a given stimulus.

In this article we will review what this concept is about and break down the most relevant aspects of it.

What are sensory thresholds?

The sensory thresholds refer to the degree to which a subject reacts to a given stimulus , taking into account the intensity required to notice it and for it to become annoying, among other parameters.

This is determined by the magnitude that exists between so-called thresholds, which are composed of minimum and maximum thresholds. The lower a person’s threshold for a specific stimulus, the less tolerance he or she will have to it. The opposite occurs when the tolerance threshold is high; in this case the subject presents a high tolerance to the stimulus, and may even be hyposensitive to it.

It can be understood then that the sensory thresholds are basically the margins of our sensations .

Your limits

Let’s see what happens when a person’s thresholds are at one of the limits, either the upper limit (higher stimulus tolerance) or the lower limit (lower stimulus tolerance).

1. Terminal threshold or upper limit

It refers to the tipping point between tolerance and intolerance. After this point any increase in stimulation has an unbearable effect on the subject , who will inevitably have to give up his resistance.

2. Absolute threshold or lower limit

This consists of the minimum degree of sensation that must exist for the subject to be able to perceive the stimulus . A lower intensity in terms of the level of the stimulus would go unnoticed by the person, as they would not be able to perceive it.

In any of these cases, a series of factors interfere, which can be biological or even related to social circumstances, the upbringing of the subject, and the environment in which he or she develops on a daily basis.

This implies that in no person there are absolute sensation thresholds, that is, these are not permanent, but rather are subject to change depending on the personal circumstances of each individual .

What is the differential threshold?

The differential threshold is the minimum difference in the intensity of a stimulus that must occur for the subject to notice the difference every other time, i.e. 50% of the time.

On the other hand, the differential threshold is greater the greater the magnitude of the stimulus . For example, adding 15 grams to one of two objects that weigh 50 grams can make the difference in weight between them noticeable, but if we add them to one of two objects that weigh 5 kilograms, the difference will not be noticed, as the differential threshold is higher in this second case.

Related theories

These are the main theories of sensory thresholds.

1. Psychophysical theory

This theory has focused most of his research on the field of absolute value, which is known as the minimum threshold, leaving aside other relevant aspects of how sensations are perceived by the subject.

2. Modern signal detection theory

With regard to this theory, there is an important variation from the previous one, since the threshold is not taken into account. Emphasis is placed on signal detection, regardless of whether or not the subject is aware that he/she is receiving a stimulus .

This is achieved through sophisticated measuring instruments, which are specially designed to quantify the intensity of a certain signal received by the organism, even though it is imperceptible to the subject’s consciousness.

Methods used for the detection of the stimulus

The following methods are often used in researching this area.

1. Limit Method

It consists of determining, using the approximate calculation, the point that may be closest to the absolute threshold that we wish to find .

2. Constant Stimulus Method

In this case the subject is subjected to the stimuli in a random way.

Your limits

Let’s see what happens when a person’s thresholds are at one of the limits, either the upper limit (higher stimulus tolerance) or the lower limit (lower stimulus tolerance).

1. Terminal threshold or upper limit

It refers to the tipping point between tolerance and intolerance.
After this point any increase in stimulation has an unbearable effect on the subject , who will inevitably have to give up his resistance.

2.
Absolute threshold or lower limit

This consists of the minimum degree of sensation that must exist for the subject to be able to perceive the stimulus . A lower intensity in terms of the level of the stimulus would go unnoticed by the person, as they would not be able to perceive it.

In any of these cases, a series of factors interfere, which can be biological or even related to social circumstances, the upbringing of the subject, and the environment in which he or she develops on a daily basis.

This implies that in no person there are absolute sensation thresholds, that is, these are not permanent, but rather are subject to change depending on the personal circumstances of each individual .