Monkeys type with their minds

Using brain implants, a pair of monkeys have reproduced some of Shakespeare's work to break a speed record for virtual typing.

"To be, or not to be" were the the first words tapped out mentally by one of the monkeys in the experiments carried out by Stanford's Krishna Shenoy and his colleagues.

They're developing brain computer interfaces with the ultimate goal of helping patients disabled by paralysing injuries or conditions like motorneurone disease, which robs sufferers of the ability to move.

The idea is to eavesdrop on the neurological chatter that goes on in the brain during the planning stages ahead a movement, and use a computer to decode and then communicate those instructions to other devices or prostheses.

Communication, however, remains tricky and quite laborious for patients, because speech movements are highly complex, and the multiple simultaneous finger actions used for typing are difficult to decode.

Instead, the Stanford team wondered whether a virtual keyboard, operated by the mental equivalent of one-finger typing, might provide a good compromise.

Two monkeys received brain implants comprising an array of tiny electrodes that were placed in their brain's chief motor areas. These were able to pick up on patterns of nerve activity within these brain regions.

The team educated their system by first using a camera to watch the monkeys spontaneously moving their arms.

Brain activity patterns corresponding to specific arm movements were identified and stored by the computer.

This meant that, shown a screen with individual letters highlighted, the monkeys had only to think about reaching out to touch that letter and the computer could detect their intention and highlight the relevant letter.

With this technique the monkeys were able to copy tracts of text they were shown, including sections of Hamlet, at speeds of up to 12 words per minute - one every 5 seconds. This is double the previous best achieved by a human patient.

The Stanford team, who have published their work this week in the journal Proceedings of the IEEE, suggest that there is also significant scope for improvement, highlighting the predictive text technology used to enable smartphone users to tap out SMS messages at high speed.

They did also admit to altering some of the Bard's text on occasion for the benefit of their monkeys, including asking one to write "A banana, a banana, my kingdom for a banana..."