Use a Paperclip to Test Your Sense of Touch
In this science experiment, kids will use a jumbo paperclip to explore their nerve endings and sense of touch.
Your ability to feel things depends on how many "receptors" you have in the place that is touching an object. Receptors sense that something is touching your skin and send messages up through your nervous system to your brain. Some parts of your body have more receptors than others, making you more sensitive in those particular areas. For example, your fingers and lips have many more receptors than your back or arms.
Create a 2-pronged tool by unbending a jumbo paper clip and re-bending it into a "U" shape with two sides that are the same length, and with points that are about 1/2" apart.
For younger children, consider putting hot glue on the ends of the paper clip to dull the points (but do not glue the prongs together).
Have a test subject close his or her eyes. Using the tips of the paper clip, touch either one or both prongs (simultaneously) to the subject's fingertip. Can the subject tell whether there are one or two prongs touching? Repeat with the subject's hand, arm and back. Most people cannot distinguish between one and two prongs on their arm or back.
Try experimenting with making the tips of the paperclip further apart or closer together. Does this change the subject's ability to distinguish between one point or two?