Turning Thoughts into Actions
The World Cup final is about to begin. You want to turn on the TV and get to the right channel. So a small area of your brain calls the motor cortex processes and sends intricate electrical signals to your arm and hand, which allow you to pick up the remote control and operate it in time to see the game. But if you don't have the use of your arms, like people who are paralyzed or have nerve or muscular damage, you have to wait for a caregiver to do it. That is, until this past year.
In June, 2004, a completely paralyzed man underwent surgery to implant a small sensor in his brain that allows him to write e-mail, play video games, change TV channels and open curtains -- using only his thoughts. Although regulatory approval is still several years away, this is the beginning of a new age of neurotechnology. For 20 years researchers studied monkeys to learn how humans go from thought to action and eventually invented a sensor that detects neural activity in the brain. This led to development of the BrainGate Neural Interface System to be used in human clinical trial.
How difficult is this surgery? The surgeon makes a craniotomy that's the diameter of a large coin. The sensor, which is the size of an aspirin with 100 tiny appendages, is implanted in the region that issues commands to the arms. The software tells the surgeon exactly where to go and the whole surgical procedure takes about two and a half hours. Afterwards only a small connector to the computer can be seen from the outside.
How does the system work? The patient directs his thoughts to move the cursor on his computer screen. The sensor in his brain picks up those hard-to-detect electrical signals and sends them through three computers that process them into signals just like those from a computer mouse. These processors, which currently sit on a cart and are not mobile, will eventually become wireless and small enough to fit inside a body. So when he is connected, the patient can just "think" the cursor from place to place on-screen like the rest of us using a mouse. He can also connect to other devices through the computer such as a TV set the control that opens and closes the curtains, a powered wheel-chair or even a mechanical hand.
Could the implant allow the patient to walk? No, not yet. Walking is extraordinarily tough. Not only do you have to move the legs, but you have to balance. And the system doesn't deal with the balance at all. If you want to understand a bit of what it's like to be paralyzed, try sitting on your hands for three hours. You can't do anything.
What if a stem-cell breakthrough allowed us to regenerate nerve function in spinal-cord-injury patients? Would that make the BrainGate obsolete? Let's hope that happens! But if stem cells are able to regenerate the spinal cord, something will have to give instruction to those growing verve fibers on how to hook up. So maybe the device can be used to help instruct the nervous system in how to use the stem cells in a more efficient way.
Could this technology be used to create super-heros, or super-villains? Technology in and of itself is neither good nor bad; it's how people apply it. Augmentation of function? Creating super-memory and super-motor abilities? Yes, researchers might come up with all kinds of applications that many people would be uncomfortable with. The ethical implications of these types of devices are worth discussing. But that can't stop this technology from helping people with disabilities. |