from The Century Dictionary and Cyclopedia
- n. In psychophysics, the limen of dual impression for the skin or retina, as determined by the esthesiometric compasses or by the just noticeable separation of black dots on a white back-ground.
Sorry, no etymologies found.
It has been held that in order to be felt as two they must be far enough apart to have a spatial character, and hence the distance necessary for two points to be perceived has been called the 'space-threshold.'
The experiments are intended to have reference chiefly to three questions: the space-threshold, fusion of touch sensations, and the perception of number.