Some 30 years ago, I played Pac-Man on the Commodore 64. Using the keyboard (and after Christmas, a joystick) I sent Pac-Man off to chase ghosts. Keyboards, joysticks… it’s all so 1983. Today, at the SURFnet Client Fair, I played Pac-Man with my mind, using sensors attached to my head. But games are only the beginning: the Donders Institute for Brain, Cognition and Behaviour at Radboud University is also working on more practical applications for thought-operated control, such as for ALS patients.
Brain activity sensor cap
But first, Pac-Man. Some preparation is necessary before play can begin. Karen Dijkstra, a researcher at Radboud University’s Donders Institute, carefully positions a cap on my head containing around ten sensors that will be used to monitor my brain activity. Then my training starts: I am instructed to concentrate on four arrows on the screen that light up. And then the game can begin. Pac-Man appears, with the same four arrows around his hungry mouth. By concentrating on one of the arrows, I can move Pac-Man in that direction. And it works!
Concentrating on the ‘down’ arrow
How does it work? The arrows light up in turn. When I concentrate on the down arrow, for example, the computer registers my brain activity whenever that arrow lights up, and that’s how it knows that I want Pac-Man to move down. It’s not perfect, because I sometimes get distracted or fail to look at the same arrow the whole time. But I still manage to earn a reasonable score – and chase ghosts with my mind.
Spelling words by thought
Of course it’s fun to play Pac-Man with your mind, however work at the Donders Institute concentrates on more practical applications. After Pac-Man, for example, I also spelled words using my thoughts by concentrating on letters on the screen. This is much more difficult for the computer than the game with Pac-Man, because I now have 26 possibilities to think of instead of four. But it still works. And that means it can help people with impairments to continue communicating (such as patients with ALS, a degenerative muscle disease). This is one of the objectives of the research being conducted by the Donders Institute.
In addition to spelling words, there are yet more applications that can be useful to patients, such as controlling their wheelchair, a language programme or a cursor on the screen. The Brain Computer Interface group at the Donders Institute conducts research into improving applications of this type, such as by searching for alternative brain signals that can be used to drive the application or by improving the method the system uses to detect the signals. As part of this research, the group regularly teams up with companies, other universities, hospitals and patient organisations.