The Two-Point Threshold
In the two-point threshold experiment it is obtained how close two distinct sharp point can be together for a person to feel two points instead of one. The value of the two-point threshold is the minimal distance at which the subject can feel two distinct points. The principle behind this experiment is the fact that mechanoreceptors are not distributed homogeneously in the skin of the human body. There are areas with a higher density and areas with a lower density of mechanoreceptors, making this certain area more or less sensitive. However, the smaller the distance is where the subject can feel two distinct points, the more mechanoreceptors must be present in this area, enabling a person to feel small details in that part of the body. In this experiment we will test the two-point threshold at five ares of the body: the back of the hand, the palm of the hand, fingertip, the back of the neck, and the calf of the leg. With these given areas, the fingertips will have a smaller two-point threshold than the back of the hand.
II. Materials and Methods
For this experiment a compass is used to apply two sharp points to the skin at the same time, and a ruler to measure the distance of these points. The independent variable for the experiment is the are where the two-point threshold is measured. The dependent variable is the two-point threshold, or in other words the smallest distance at which the subject can distinguish between one and two points at one of the five tested areas. At first the compass is set on the smallest value, 2mm, and applied to a certain area. If the subject does not feel two distinct points the distance between the points will be increased until the subject can feel two points. That way the smallest distance, the two-point threshold is obtained.
The Two-Point Threshold Values For All Subjects
First the average two-point threshold is calculated for both...
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