What is the purpose of the two-point threshold test?

The two-point threshold test is primarily used to measure the smallest distance at which two points of stimulation can be perceived as distinct rather than as a single point. This concept is integral to understanding sensory perception, particularly in relation to touch.

When the skin is stimulated at two separate points, if the distance between these points is greater than the two-point threshold, the brain interprets them as two separate stimuli. If the points are closer than this threshold, the brain perceives them as one point of contact. This measurement varies across different regions of the body due to the density of sensory receptors, providing insight into the spatial resolution of tactile sensation. Thus, the purpose of this test directly relates to quantifying sensory perception capabilities and is foundational in studying the somatosensory system.