The more sensitive a sense organ is, the __________ the Weber fraction required for stimulus detection.

The Weber fraction is a concept in psychophysics that quantifies the smallest detectable change in a stimulus relative to the magnitude of the original stimulus. It is defined as the ratio of the just noticeable difference (JND) to the original stimulus intensity. When a sense organ is more sensitive, it can detect smaller changes in stimuli, meaning that the JND required for detection will be smaller in relation to the original stimulus intensity.

In this context, a smaller Weber fraction indicates that even a slight change in stimulus intensity can be detected because the sensitive organ is attuned to finer variations. Therefore, as sensitivity increases, the Weber fraction decreases, leading to the conclusion that a more sensitive sense organ requires a smaller Weber fraction for stimulus detection. This relationship highlights the efficiency of sensitive sense organs in processing environmental stimuli.