Explain the difference between absolute threshold and difference threshold.
The absolute threshold and difference threshold are concepts within the field of psychophysics that describe the limits of perception for humans.
The absolute threshold refers to the minimum level of intensity or stimulus required for a person to detect a sensation. It is the point at which the stimulus is just barely detectable 50% of the time. In simpler terms, it is the weakest stimulus that a person can perceive. For example, in vision, the absolute threshold is the minimum level of light needed for a person to see an object. It varies depending on the sense being tested.
On the other hand, the difference threshold (also known as the just noticeable difference or JND) refers to the minimum level of difference between two stimuli required for a person to perceive a change. It is the smallest detectable change or the smallest noticeable difference between two stimuli. For example, if you have a pile of sand and you keep adding grains to it, there will come a point where you will notice that the pile has grown bigger. The difference threshold is the amount of added sand needed for you to perceive the change.
In summary, the absolute threshold is the minimum intensity needed to detect a stimulus, while the difference threshold is the minimum change needed to perceive a difference between two stimuli. The absolute threshold refers to detection of a stimulus, while the difference threshold refers to perception of a change or difference in stimuli.