Key Concepts
Biology
Senses
Perception
Touch

Introduction
Have you ever been in an elevator and wondered what the many little dots on the buttons are for? You can also find these dots in public buildings on room number signs or on ATMs (cash machines). These arrangements of dots are a special writing system for the visually impaired called braille. By feeling the dots with their fingers, people can read what is written on a sign or elevator button. Do you want to find out how to read with your fingers? This activity will show you how!

Background
For a long time being able to see was a prerequisite for reading. No other reading medium was available for people who were blind or had impaired vision. This changed only in the early 1800s when Samuel Gridley Howe, the founder of the New England School for the Blind, created Boston Line Type, the first writing system for the blind. The system was based on a tactile reading code, which means reading by touch, and consisted of an embossed, simplified Roman alphabet.

This type of reading is possible because our fingertips contain a huge network of nerve endings and touch receptors that allow us to detect tiny bumps on a piece of paper. Once these touch receptors are activated by feeling a bump, a signal is sent from the nerves in our fingertips all the way into our brain, which is then able to decode the information we gained by touching the paper.

The braille system was developed by Louis Braille in the 1820s and consists of raised dots arranged in a six-dot cell. A different pattern is assigned to each letter of the alphabet. Braille got this idea from a military code called night writing. Night writing allowed soldiers to communicate during the night without making any sounds or using light. Although several other tactile writing systems have been developed over time, braille was widely adopted and is still in use today. Do you want to test your sense of touch and find out how to read these dots? Grab a piece of paper and get started!

Materials

  • Graph paper
  • Parchment paper
  • Pencil or other pointed object, such as a knitting needle
  • Cardboard
  • Computer or mobile device with access to the Internet
  • Tape
  • Helper


Preparation

  • On the Internet look up the braille alphabet to see which dot pattern stands for each letter.
  • Place the graph paper on top of the cardboard.


Procedure

  • Choose one square of the graph paper, and gently press down on the paper with the tip of the pencil or knitting needle—being careful not to puncture the paper.
  • Flip the graph paper over. Can you see the raised bump in the paper? Run your index fingertip over the punched spot. How does it feel? What letter does one dot stand for?
  • Repeat this step, but this time choose two squares next to each other and punch one dot lightly onto the paper with the tip of the pencil in each square. When you flip your paper over can you feel both bumps next to each other with your fingertips? Which letter does your chosen dot pattern stand for?
  • Next place the parchment paper onto the graph paper, and tape them together. Think of an entire word to write. With the help of the braille alphabet you found online draw the corresponding dot patterns for your word onto your parchment paper. The graph paper underneath will help you to keep the dots in line.
  • Place the graph paper on top of the cardboard, flip over the parchment paper, and lay it on top of the graph paper.
  • Press on each dot of your dot pattern written on the parchment paper to create bumps in the graph paper underneath. Once you are done flip your graph paper around and try to read the word with your fingers. Are you able to make out the individual letters? Can you read the whole word? Does it make a difference if you read with your eyes closed or open?
  • Ask your helper to create a single letter dot pattern for you the same way you did in the first step. He or she should keep the letter secret from you. Once your helper has completed the dot pattern check the braille alphabet once more, and then close your eyes. Try to identify the letter with your fingertips without looking. Can you identify the correct letter?
  • Repeat this challenge as many times as you like—or make it more difficult and ask your helper to write a whole word in braille for you. Can you read the word with closed eyes?
  • Extra: Does it make a difference which fingertip you use for reading? Try using your middle finger or pinky instead of your index finger and see which finger is best in identifying the writing.
  • Extra: You can also read braille with two hands. Braille readers use the index fingers of both the left and right hands simultaneously to reduce their reading time. How does reading with one hand compare to reading with two hands?
  • Extra: Try to change the spacing between your dots. Can you read your letters better if the dots are closer to one another or farther apart?

Observations and Results
Were you able to read with your fingers? It can be quite challenging if you are not used to it. But you should have been able to feel the bumps on the graph paper that you made with your pencil. If you run your index finger across the paper, the touch receptors in your fingertips recognize the difference between the flat paper and the bump. This triggers your receptors and they send a signal from the nerves in your fingertips to your brain. This way you know how many bumps you felt on the paper and in which position in the six-dot cell they were.

Usually the index fingers are used to read braille, although the other fingers should also have been able to identify the bumps. It makes a difference how close or far apart you space the individual dots. If they are too far away, one fingertip alone is not able to detect them anymore. If they are too close together, your finger might not be able to identify them as two separate dots. Now that you know how braille works try reading it with your fingers the next time you see it!

More to Explore
A Brief History of Tactile Writing Systems for Readers with Blindness and Visual Impairments, from Texas School for the Blind and Visually Impaired
Brainy Processing at Your Fingertips, from The Guardian
Skin-Deep Science: Find Your Sensitive Side, from Scientific American
STEM Activities for Kids, from Science Buddies

This activity brought to you in partnership with Science Buddies

Science Buddies