How your tongue could help you 'see'

A. Researchers in America have developed a device that transmits visual clues to the brain via the tongue.�Its developers call it a 'tongue display unit' (TDU).

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Q. How does the tongue display unit work

A. A video camera feeds signals to the TDU, a stamp sized grid of 144 gold-plated electrodes, via a small box of electronics. The user then feels a tingling sensation on their tongue which directs them accordingly. For example the sensation is picked up by the right side of the tongue if they need to make a right turn.

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Q.�Of all our sensory organs why is the tongue used

A.�Because the tongue contains a high density of nerve fibres and mechanosensors it's highly sensitive to touch. A large part of our brain is dedicated to the tongues sensory perceptions. Also, because our tongue�is always covered in saliva, they make excellent conductive surfaces for electrical impulses.

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Q.�How easy is it to use your tongue to see using the TDU

A.�Researchers say that it takes about 50 hours of practice to become familiar with the unit, learning to interpret the signals in a similar way to Braille. However the TDU does produce a fizzy sensation which researchers hope won't impede its effectiveness.

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Q.�How can the tongue display unit be used

A.�In a test a volunteer, Cheryl Schiltz used the TDU to navigate her way through a maze, making simple right, left and straight manoeuvres. She described the device as 'amazing' in its ability to tell her exactly where to go. Within the next few years researchers�hope to develop an inconspicuous unit which could help people move about in the dark or deep water. US Navy diving teams have already tested a system in murky waters. However, the Royal National Institute for the Blind (RNIB) in the UK were more sceptical about the researchers hopes for the TDU helping blind people. The RNIB warned that the TDU was still at the prototype stage and a fully developed version would be prohibitively expensive.

by Lisa Cardy