Assignment task: Explain the difference between the absolute threshold and the difference threshold.
Information:
To define the phenomenon that relates to the level at which a stimuli must occur before an organism senses that stimulus, we use the term absolute threshold. Absolute threshold is the absolute minimum of stimulation that it would take for an organism to perceive something happening around it 50 percent of the time.
Examples of absolute thresholds that are significant in real life are:
- How loud does a baby have to whimper before its mother hears her?
- How much noise does an intruder have to make before you hear him?
- How bright a blip on the radar screen does it take for an air traffic controller to see an incoming plane?
The phenomenon that relates to the level at which a stimuli must occur before an organism senses that stimulus is called Absolute threshold_.
Difference Threshold:
In order to assess very small changes in various stimuli, we need to have very low difference thresholds. An example would be the ability to detect the difference in volume between two sounds or the difference in brightness between two lights. The difference threshold has to do with that smallest increase of intensity in a stimulus that a person can sense.
In humans, a difference threshold (also called a just noticeable difference, or JND) increases in proportion to the size of the stimulus-a principle known as Weber's law. Weber's law says that the difference between thresholds is always in proportion to the size of the stimulus. For example, you might not notice a 1 cent increase in a Big Mac, but you will probably notice a 25 cent increase. You would not notice a 25 cent increase on the price of a new car, but you will probably notice a $500 increase.