Now, paralysed people can play music just by thinking about it

In the trial, a pianist played a series of notes, and the woman echoed them on a computerised music system. The woman then played a simple improvised melody over a looped backing track. But the woman was paralysed after a stroke, and can make only eye, facial and slight head movements, reports Nature.

This computer-music system interacts directly with the user's brain, by picking up the tiny electrical impulses of neurons. Composer and computer-music specialist Eduardo Miranda of the University of Plymouth, UK, working with computer scientists at the University of Essex, have developed the device.

It should eventually help people with severe physical disabilities, caused by brain or spinal cord injuries to make music for recreational or therapeutic purposes.

Miranda and his colleagues have used one of the oldest of these systems: electroencephalography (EEG), in which electrodes on the skull pick up faint neural signals. The EEG signal can be processed quickly, allowing fast response times, and the instrument is cheaper and more portable than brain-scanning techniques such as magnetic resonance imaging and positron-emission tomography.

Previous efforts using BCIs have focused on moving computer screen icons such as cursors, but Miranda's team sought to achieve the much more complex task of enabling users to play and compose music. Miranda said that he first became aware of the then-emerging field of BCIs more than a decade ago while researching how to make music using brainwaves.

The trick is to teach the user how to associate particular brain signals with specific tasks by presenting a repeating stimulus — auditory, visual or tactile — and getting the user to focus on it. This elicits a distinctive, detectable pattern in the EEG signal.
Miranda and his colleagues showed several flashing buttons on a computer screen, which each trigger a musical event. The users push a button just by directing their attention to it.

With a little practice, this allowed users to create a melody as if they were selecting keys on a piano. And, as with learning an instrument, say the researchers, "the more one practices the better one becomes".

The findings have been published in the journal Music and Medicine1.