Journeys: Nerves. Stop 3

One or two?

An experiment for two! Ask a grown-up to touch your back with two fingers very close together. No peeking!

How many touches do you feel?

One, though there were two fingers! The back has few sensors, so the touches merged.

Two? Then ask them to put the fingers even closer. On the back, touches merge.

Now the same two fingers on the tip of your finger. How many?

Two! Fingertips have lots and lots of sensors.

Ask them to spread the fingers a little. On a fingertip you will feel both.

That is why you can read with your fingers. Blind people read the raised dots of Braille with their fingertips.