Giggles rang through the operating theatre. They came from Kenny, a middle-aged man with Parkinson's disease, who sat shaking uncontrollably in front of me, a steel frame enclosing his head.
Behind him, a surgeon was inserting a probe through holes bored in his skull. A moment later, the laughter vanished to be replaced by palpable fear. "I'm so cold," he shivered. The surgeon moved the probe again. Kenny grinned. "The seaside," he shouted. But it was another slight shift of the probe that caused the most dramatic reaction of all. In an instant, Kenny's shaking stopped.
That was a London hospital in the early 90s and I'd just witnessed the extraordinary scenes of a man, fully awake, having a device implanted in his brain to control the distressing tremor of Parkinson's. It was a first then. Today more than 30,000 people with Parkinson's have undergone this technique, called deep brain stimulation. The implant is connected to a small computer, which is inserted under the skin on the chest. This generates electrical signals that stimulate the brain.
Like cochlear implants that restore hearing, or retinal implants (now in early trials) that return some vision, deep brain stimulation is an example of a direct interaction between the human brain and a machine, and promises big breakthroughs in how we treat illness and disability.
The future, however, is broader than this and breakthroughs are likely to come as much through video games as medicine. And it promises a world where we can not only reverse physical deficiencies but regularly - and cheaply - control machines with our thoughts.
Translating thought into action has already been demonstrated, albeit in fewer than a dozen cases worldwide, and all rely on a neural prosthesis implanted in the brain. Erik Ramsey, for example, has "locked-in" syndrome. The 26-year-old from Georgia was paralysed completely by a car crash at 16, leaving him unable to move or talk, but with 100 per cent sensation in his body.
Now, thanks to an implant in 2004 when he was 21, when he thinks of saying something his prosthesis picks up electrical firing in neurons in an area of the brain that (even though they no longer work). The impulses are transmitted to a computer, which decodes them and produces a sound. Ramsey has mastered some vowel sounds; neurologist Philip Kennedy of Neural Signals, the US company that developed Ramsey's device, predicts that he will have a full range of speech within two years.
Similar devices have been used to steer a wheelchair, put words on a screen and, in the case of Matthew Nagle, a young American from Massachusetts whose spinal cord was severed in a fight in 2001, to open and close an artificial hand. There are now nearly 40 groups worldwide working on similar BCIs (brain-computer interfaces), reflecting in part the funding that has become available to meet the needs of disabled soldiers returning to the US from Iraq and Afghanistan.
The advances that these technologies represent are stunning; even so, such devices require surgery, are limited in their effect, and are very costly, and need technicians to monitor them. Matthew Nagle, who died in 2007 from an unrelated problem, was attached to his kit via a big cable. It's hardly independence.
And the brain tends to cover the implant with gunk, quickly making it less effective and prone to infection.
Indeed, not all researchers agree that implants are the answer.
Computer scientist Paul Gnanayutham of the University of Portsmouth says: "Surgery is unnecessary. Picking up brainwaves is not rocket science. It's a technology that has been available since 1925."
Gnanayutham is talking about EEG (electroencephalography), which detects brainwaves via electrodes on the scalp, and which is in everyday clinical use. Gnanayutham customises existing software combined with a sensor-rich headband - yes, it does look like the thing LaForge sports in Star Trek - writing code for the specific needs of profoundly disabled patients. He uses an existing interface, the $2,000 Cyberlink, produced by Brain Actuated Technologies in Ohio, which develops hands-free computer devices.
The Cyberlink picks up brainwaves but also detects impulses from the twitching of forehead muscles, which enable patients to move a cursor on a screen when they frown. Gnanayutham's preference for muscle signals goes to the heart of a big problem: "They are 1,000 times stronger than brain waves. The voltages from brain waves are tiny and they are very variable from one person to another." This variation is caused by the cortex, whose pattern of surface folds is as individual as a fingerprint and affects how the signal can be picked up once it has passed through the skull.
Yet it is a problem that has been addressed - and many think may well have been solved - by the technology entrepreneur Tan Le, whose family fled Vietnam by boat in 1981 when she was four years old. They made Australia their home and, by the age of 20, in 1997, Tan Le had been named Young Australian of the Year.
After successfully starting and running a telecommunications company there, she co-founded Emotiv in 2003, a joint US-Australian venture that has developed a neuroheadset that makes it possible for games to be controlled and influenced by players' minds.
The Epoc headset had to be wireless, gel-free (unlike conventional EEG caps) and, the biggest challenge of all, work every time, on everyone. It wasn't easy. "Many, many times we thought this is just not going to work," she says. "We would get ten seconds of Epoc data and it would take a whole weekend to process."
But the company has now made a working prototype of a portable EEG-acquisition system optimised for a consumer setting. The price?
Around US$300.
Using it for the first time involves a game in which you're asked to lift, push or turn an object on the screen, as well as gurn at it to develop its understanding of your facial expressions. The platform has been released to developers and there are a number of products in the pipeline, such as mini devices for interactions with computers on the move. Many of those who've tried it, however, find the experience unnerving.
"We need to have controls," says Tan. Though she then starts talking about "neuromarketing", in which you are given a free headset if you watch an advertisement and have your reactions to it recorded.
But let's return to Kenny. One side-effect of deep brain stimulation is its effect on mood, and it is already in use to treat severe depression. Two-way headsets could not only read your intentions but might also be used to change your mood - in the same way that today some people use recreational drugs. And that really would be a new stage in the relationship between men and machines.
Vivienne Parry is a science correspondent and former presenter of Tomorrow's World
This article was originally published by WIRED UK
