We explain the difference between absolute threshold and difference threshold with table. The perception of reality that each individual has is created through the information received by the sensory receptors present in the human body. This information is transferred to the brain in the form of electrical signals, which it receives and interprets as experiences.
Psychophysicists often use the term “threshold” when dealing with the senses and perception. Threshold means the limit values at which an individual perceives or interprets something. For example, there is a minimum value at which someone can perceive a certain stimulus. This value is a threshold.
The difference between the absolute threshold and the difference threshold is that the absolutes threshold is the minimum amount of stimulation that one can interpret or perceive, while the difference threshold is the minimum amount of change required in the intensity of a stimulus, to that someone can interpret a difference.
Comparison table between absolute threshold and difference threshold
| Comparison parameters | Absolutes threshold | Difference threshold |
| Sense | The absolutes threshold is the minimum amount of stimulation that an individual can interpret or perceive. | The difference threshold is the minimum amount of difference in the intensity of a stimulus so that someone can interpret a change. |
| Stimulus condition | There is no change in the intensity of the stimulus while determining the absolutes threshold. | There has to be a change in the intensity of the stimulus while determining the difference threshold. |
| Determined value | The determined value specifies the least amount of intensity. | The determined value specifies the least amount of intensity change. |
| Difference | The absolutes threshold varies between different people and also between people and animals. | There is only a slight variation between the difference threshold of different people. |
| Example | The minimum distance at which a person can see a lit candle clearly. | The minimum difference in distance required for a person to notice the change in position. |
What is the absolute threshold?
Initially, according to neuroscience and psychophysical studies, the absolutes threshold referred to the minimum level of intensity of a stimulus at which a person’s sensory receptors could perceive it. For example, the lowest volume that can be heard, the shortest distance to which it can be seen clearly, the smallest amount of concentration of a fragrance that can be smelled, etc.
However, it was subsequently observed that internal or external factors could influence a person’s absolutes threshold. For example, a person can easily taste food when the level of health is good. But when catching a slight cold, the intensity of the taste when eating the food decreased. This made it difficult to determine the absolutes threshold of the individual, since health conditions are prone to change at different times.
To counteract this problem, it was decided to change the definition and the method for determining the absolutes threshold. Now, physicists would run multiple tests on a person over a set period. The value that turned out to be true fifty percent of the time would be called the person’s absolutes threshold.
Currently, the absolutes threshold is the least amount of intensity at which an individual can perceive a stimulus fifty percent of the time. The idea behind this modification is known as single detection theory. It states that there is no single absolute threshold due to other influencing factors.
What is the difference threshold?
The difference threshold is the minimum amount of difference required in the intensity of a stimulus for an individual to be able to perceive or detect a change. It is also known as ‘Barely Perceptible Change’ (JND). Like the absolute threshold, a person should be able to detect the same value at least fifty percent of the time.
Some examples of threshold difference are: the smallest increase in sound intensity for one to detect a change in TV volume, the minimum distance a person can see an object clearly, the minimum amount of heat required to feel that the food is hot, etc.
Weber’s law is a significant law of psychology that quantifies the detection of changes with respect to a given stimulus. According to the law, as the intensity of a stimulus increases, it becomes increasingly difficult to perceive a change or difference. For example, if the volume of a television is already very high, it would be difficult for a person to detect whether the volume has increased more or not.
To get a clear understanding of Weber’s law, imagine a television that plays at volume 5. Now if you switch to volume 10 (an increase of 100%), the difference in sound will be noticeable. However, the sound change between volume 50 and 55 will not be the same value. For a person to be able to notice it, volume 50 will need to be changed to volume 100 (an increase of 100%).
Main differences
- The absolute threshold is the minimum amount of intensity required for one to detect a stimulus, while the difference threshold is the minimum amount of difference in intensity required for one to detect a change.
- Unlike the difference threshold, the absolute threshold does not imply any change in the intensity of the stimulus.
- The absolute threshold determines the minimum intensity value while the difference threshold determines the intensity change value.
- The absolute threshold varies greatly from person to person, as well as from animals, while there is only slight variation in the difference threshold for different people.
- The absolute threshold is the minimum amount of volume at which a person can detect sound. On the other hand, the difference threshold is the minimum amount of change in volume for a person to detect.
Final Thought
The absolute threshold and the difference threshold are important concepts of meaning and perception. The difference between the two can be understood by the fact that the absolute threshold determines the minimum intensity value while the difference threshold determines the minimum intensity change value.
