Computer mind meld gives voice to man after a stroke

[Nipuna]

LOCKED in but not shut out: for the first time people who have lost the ability to move or talk because of a stroke may be able to communicate with their loved ones using a brain-computer interface.

Brain injuries can leave people aware but almost completely paralysed, a condition called locked-in syndrome. Brain-computer interfaces (BCIs) can help some people communicate by passing signals from electrodes attuned to their brain activity as they watch a screen displaying letters. Subtle changes in neural activity let researchers know when a person wishes to select a particular on-screen item, allowing them to spell out messages by thought alone.

Until now, BCIs have only been tested on healthy volunteers and people with amyotrophic lateral sclerosis, a neurodegenerative disease that leads to muscle wasting. But no one had tested whether the technology could help people locked in after a brain stem stroke.

Now Eric Sellers and his colleagues at East Tennessee State University in Johnson City have tested the technique on a 68-year-old man. After more than a year of training he learned to communicate reliably via the BCI. He took the opportunity to thank his wife for her hard work, and to give his thoughts on gift purchases for his children (Science Translational Medicine, DOI: 10.1126/scitranslmed.3007801).

Sellers says he can imagine a future where every hospital has a BCI. For that to happen the technology will need to become cheaper and more efficient. A device costs about $10,000, and a user can spell out a typical message in around an hour. However, scaling up the technology will only happen if larger trials are carried out – something that's not easy with a rare condition that is difficult to diagnose. "It's a supply and demand issue," says Sellers.

This article appeared in print under the headline "Mind meld gives voice to man after stroke"