Card 8 / 22: Watch this video ( http://openstaxcollege.org/l/2point ) to see a quick demonstration of two-point discrimination. Touching a specialized caliper to the surface of the skin will measure the distance between two points that are perceived as distinct stimuli versus a single stimulus. The patient keeps their eyes closed while the examiner switches between using both points of the caliper or just one. The patient then must indicate whether one or two stimuli are in contact with the skin. Why is the distance between the caliper points closer on the fingertips as opposed to the palm of the hand? And what do you think the distance would be on the arm, or the shoulder?
Answer:
The fingertips are the most sensitive skin on the hand, so the points of the caliper can be closer together and still be recognized as two separate points. On the palm, the sensitivity is less, so the points need to be farther apart. This will continue on the arm and shoulder, as sensitivity decreases, the discrimination of separate stimuli will be wider.
Previous Card | ← Previous Card Button |
Next Card | → Next Card Button |
Flip Card | Space-Bar |
|