Someday, Farah suspects, we may look back at the cognitive enhancers of the early twentieth century as the first step towards a Singularity-like era. "I think this growing practice may be softening us up to accept more drastic brain modifications down the line," she said.
"Here are some critters," said Ed Boyden. The serene young leader of the Synthetic Neurobiology Group at MIT stood in a laboratory strewn with miniature pieces of electronics. Dishes of neurons were positioned under microscopes. And on the lab benches were also bright green flasks of algae, one of which Boyden was sloshing as he spoke with me about the future of the brain.
I came to Boyden's lab after seeing him give a remarkable talk at the Singularity Summit. Boyden belongs to the young field of neuroengineering, which seeks to restore damaged brains by implanting tiny on-board computers and electrodes. Boyden's research may take change the rules of the neuroengineering game by allowing scientists to manipulate the brain not with electricity, but with light. But in order to do that, Boyden was borrowing genes from the algae he was holding in the green flask. If he succeeds, people will become part machine, and part algae too.
The logic behind brain implants is simple. Many disorders, such blindness to paralysis, come down to a break in the flow of signals through our nervous system. Neuroengineers have long dreamed of building tiny machines that could restore that flow. So far, they've had one great success: the cochlear implant, a machine that delivers sound to the brains of the deaf. A cochlear implant picks up sounds with an external microphone and converts them to electronic signals, which travel down wires into a shell in the ear called the cochlea, where they tickle the ends of the auditory nerves.
The first generation of cochlear implants emerged in the 1970s. They were big, awkward devices with wires crossing the skull, raising the risk of infection. They used up power quickly and produced crude perceptions of sound. In the 1990s scientists developed microphones small enough to perch on the ear that transmit sounds wirelessly to an implanted receiver. Today more than 180,000 people use cochlear implants. Scientists continue to make improvements to the implants so they can run on far less energy yet perform even better.
Neuroengineers have also been testing implants that go into the brain itself, but progress has been slower on that front. As of 2010, 30,000 people have had electrodes implanted in their brains to help them cope with Parkinson's disease. Pulses of electricity from the implants make it easier for them to issue the commands to move their bodies. Other scientists are experimenting with similar implants to treat other disorders. In October 2009 scientists reported 15 people with Tourette's syndrome had 52 percent fewer tics thanks to deep-brain stimulation. Other scientists are trying to build the visual equivalent of a cochlear implant. They've linked cameras to electrodes implanted in the visual centers of blind people's brains. Stimulating those electrodes allows the subjects to see a few spots of light.
Scientists are working not just on input devices, but output ones as well. At Massachusetts General Hospital doctors have started clinical trials on human volunteers to test brain implants that give paralyzed people the ability to control a computer cursor with thought alone. Other neuroengineers have been able to achieve even more spectacular results with monkeys. At the University of Pittsburgh, for example, monkeys can use their thoughts to feed themselves with a robotic arm.
These are all promising results, but brain implants are still fairly crude. When the electrodes release pulses of electricity they can't target particular neurons; they just blast whatever neurons happen to be nearby. The best electrodes for recording brain activity, meanwhile, can pick up only a tiny portion of the chatter in the brain because engineers can implant only a few dozen electrodes in a single person.