A MAN has been able to control a computer by thought alone after receiving an electronic implant that fused with his brain cells.
The most immediate application of this marriage of man and
machine would be for people who are totally paralysed, enabling them
to express their thoughts or even control artificial limbs. The
American surgeons involved say it is the first time that such a
connection has been made directly in the brain, rather than with
nerves in the spine or limbs.
 |
"If you can run a computer you can talk to the world," said Dr Roy Bakay, of Emory University in Atlanta, Georgia, whose team developed the implants. He told a meeting of brain surgeons that he had performed two of the operations in which he persuaded the patients' brain cells to grow into his implant, linking up with its electronics.
One of the patients, a 53-year-old man known only as JR, was almost totally paralysed by a stroke. He is dependent on a ventilator and cannot speak, although he is fully alert and intelligent and knows everything that is going on around him. Once he received the implant he could control a cursor on a computer screen and point at different icons, triggering a computer voice to make comments such as "I'm thirsty".
Now that JR, who is in the Atlanta Veterans Affairs Medical Centre in Georgia, can select phrases, his favourite is: "See you later. Nice talking with you." The first volunteer, a woman suffering from a neuro-degenerative disease, was given the implants 18 months ago and has since died.
Dr Bakay said: "The trick is teaching the patient to control the strength and pattern of the electric impulses being produced in the brain. After some training they are able to 'will' a cursor to move and then stop on a specific point on the computer screen. If you can move the cursor you can stop on certain icons, send e-mail, turn a light on or off and interact with the environment.
"Our hope is that soon we will be able to get to the point that we can connect the neural signals to a muscle stimulator in the patient's paralysed limb and have them move that limb using the same principle that they use to move the cursor."
Dr Bakay told the Congress of Neurological Surgeons in Seattle that the implants consisted of two hollow glass cones, each no bigger than the tip of a ballpoint pen.
Each cone contained a tiny electrode. The doctors also inserted a natural human substance that encourages nerves to grow, which they extracted from the man's knee. They inserted the cones into the patient's motor cortex, the region of the brain that controls movement.
Once the cones were inserted, the growth factor substances encouraged the man's brain cells to grow. Over several months they spread into the cones and attached themselves to the electrodes.
When the patient learned to think in the correct way, he could routinely trigger the electrode to send a signal to a small transmitter-receiver placed just inside the skull. This transmitted to an amplifier worn outside the skull in a cap, which boosted the signal and sent it to the computer. Controlling the cursor soon became second nature, said Dr Bakay. But he added that it might take several more years before the implants could be used to give more complex commands.
To reach this stage had taken eight years, according to New Scientist magazine. Prof Kevin Warwick, a cybernetics expert at Reading University, said: "If they have actually gone into the brain and picked up signals with electrodes that is very new. It is another very exciting step." He said that one of the major obstacles to the production of such a cyber-human had been the moral issue of tampering with the brain of a healthy person.
John Cavanagh, of the International Spinal Research Trust in Cheshunt, Herts, said: "If these implants can be developed then they could do an enormous amount to alleviate many illnesses." The team has been given funding to continue research with three more patients.