Chorost's article is about the dawning of the age of "optogenetics," a field where scientists stimulate neurons (such as those in your brain) to fire or stop firing by genetically-engineering those neurons to respond to light. Thus, optogenetics: optics plus genetics. An inserted algae gene makes neurons fire when exposed to blue light; an inserted bacterial gene stills them when they're exposed to yellow light. Imagine being able to make the neurons responsible for chronic depression or Parkinsons stop firing with the flick of a switch. That's the dream of the scientists who are working in this field.
You've probably heard about a few optogenetic experiments over the past couple of years. Chorost describes one of the more famous ones, where students got a mouse to run counterclockwise by exposing a few neurons in its brain to blue light using fiber optic wires. He writes:
The counterclockwise-running mouse was something new - a triple fusion of animal, plant, and technology - and the students knew it was a harbinger of unprecedentedly powerful ways to alter the brain. For curing diseases, to begin with, but also for understanding how the brain interacts with the body. And ultimately for fusing human and machine.Mice with Parkinsons symptoms who underwent optogenetic treatment also saw dramatic improvement.
And Chorost is quick to point out that Parkinsons treatments are just the beginning. Optogenetics open the door for two-way traffic between computers and the human brain. He explains:
No matter how good they get, one-way prostheses can't close the loop. In theory, two-way optogenetic traffic could lead to human-machine fusions in which the brain truly interacts with the machine, rather than only giving or only accepting orders. It could be used, for instance, to let the brain send movement commands to a prosthetic arm; in return, the arm's sensors would gather information and send it back. Blue and yellow LEDs would flash on and off inside genetically altered somatosensory regions of the cortex to give the user sensations of weight, temperature, and texture. The limb would feel like a real arm. Of course, this kind of cyborg technology is not exactly around the corner. But it has suddenly leapt from the realm of wild fantasy to concrete possibility.Of course, there are darker fantasies that lurk here too, of perfect mind control and memory suppression. Indeed, optogenetic devices could one day lead to the consumer-grade memory-eating devices in Eternal Sunshine of the Spotless Mind. Or to Google implants in your brain.
You have to read this mind-blowing, brilliantly-written article: http://www.wired.com/magazine/2009/10/mf_optigenetics/all/1