There’s a lengthy but interesting piece up over at Wired about the relatively young discipline of optogenetics – the science of isolating and communicating with specific types of neuron using light. The discovery of the process is an interesting story in its own right, but the really futurismic bit is the implication tucked into the final few paragraphs:

Optogenetics has amazing potential, not just for sending information into the brain but also for extracting it. And it turns out that Tsien’s Nobel-winning work — the research he took up when he abandoned the hunt for channelrhodopsin — is the key to doing this. By injecting mice neurons with yet another gene, one that makes cells glow green when they fire, researchers are monitoring neural activity through the same fiber-optic cable that delivers the light. The cable becomes a lens. It makes it possible to “write” to an area of the brain and “read” from it at the same time: two-way traffic.

Why is two-way traffic a big deal? Existing neural technologies are strictly one-way. Motor implants let paralyzed people operate computers and physical objects but are incapable of giving feedback to the brain. They are output-only devices. Conversely, cochlear implants for the deaf are input-only. They send data to the auditory nerve but have no way of picking up the brain’s response to the ear to modulate sound.

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.

Science fiction has been talking about the brain-machine interface for decades, but usually in terms of splicing the hardware into the nervous sytem in much the same way as connecting up a regular electronic circuit, and with little experimental evidence for its viability. As Chorost points out in the Wired piece, we’re not going to see commercially available optogenetic interfaces for some time yet, but this proof-of-concept work suggests it really is only a matter of time before we do. [image by LoreleiRanveig]