It will be a long time before scientists successfully convert experimental methods using electrodes to a fully-functioning, implantable chip, but there is an indirect alternative being developed. Transcranial direct-current stimulation (tDCS) is a way of running electrical current through the brain with electrodes attached to the outside of the skull. The US Defence Advanced Research Agency (Darpa) currently uses tDCS to improve the learning speed of snipers, claiming it cuts the learning curve by a factor of 2.5. There are issues, though. "They learn more quickly but they don't have a good intuitive or introspective sense about why,” says Vincent Clark, neuroscientist at the University of New Mexico.
Such devices were initially expensive, but now GoFlow sells a DIY kit for $99, which consists of two electrodes, cables and a 9-volt battery. So, in theory, everybody can try and tune his or her own brain at home. But if it is not applied correctly, anything could happen – from enhancing intelligence (intended), rewiring our brains (who knows?) through to electrocuting ourselves (not intended). Neuroscientist Roi Cohen Kadosh from Oxford University says he wouldn’t buy the DIY kit, because he thinks it is premature to distribute it to non-experts. “People might feel like they should stimulate their brain as much as they want, but just as buying a medicine on the counter, you need to know when to use it, how often, in what conditions and in what cases you should not take it.”
So when will we be ready to plug in brain chips to think faster? "As for the technology, we will be ready very soon," says Verschure. He is convinced that it will take at least 10 years before his artificial cerebellum will actually make it into a human brain. To do so, researchers must also solve technical problems, such as providing low-voltage power supplies for the prostheses. Another, more general, problem is that not all other brain regions are as well characterised, “and this won’t change so soon", says Verschure.
Like any other type of medical implant, neuroprostheses mustn’t cause any unwanted reaction once they are in the body. The spiky microelectrodes are mostly made of platinum, silver and iridium, all of which are quite biocompatible and cause relatively few reactions. However, upon implantation the electrodes can injure the brain’s tissue, which in turn becomes inflamed, scarred and eventually non-responsive to electrical stimulation. As a result, the brain implant can’t work anymore, as a study found.
Another issue that might prevent neuroprostheses from being applied soon, according to Tel Aviv University’s Mintz, is the host of unanswered ethical questions. “How many neurons do we have to replace by machine parts until we consider our brain a machine?” he asks. “A hundred? Millions? Are we still humans then?” Mintz thinks these questions should be discussed at length by ethics and law commissions before products are ready to hit the market. That said, he still believes in the success of neuroprostheses. “I think it will not be possible to stop this technology,” he says.
While researchers address technical and health issues, there’s one issue that hasn’t been explored as much – security. Hackers could pick up and alter electrical signals from neuroprostheses, just like any other signal in the world. “They could manipulate a person and let him or her do what they want,” claimed Jens Clausen, Professor of Bioethics at the University of Tübingen, Germany, in 2006.
Being a computer scientist myself I know how easy it is to pick up wireless signals, manipulate and re-inject them. I cannot imagine a brain implant hitting the market without proper encryption of the transmitted signals. Why would we protect our WiFi networks and not do the same for our thoughts? After all, wireless data transfer technology for neuroprostheses is already underway.