Optogenetics is a relatively new technique for communicating with the brain.  It involves implantation of light-sensitive genes into animals and then hooking up fiber-optic cables to specific areaa of the brain. 

Researchers have used this technique to completely restore movement in mice with Parkinson’s disease, and to reduce anxiety in other mouse models.   

Researchers are now trying to develop a less invasive method that doesn’t go deeper than the outer surface of the brain.

Eventually, two-way traffic may be possible with this technique, in which a machine can both send and receive information from the brain.

Read about it in Wired and the NYT below.

http://www.wired.com/magazine/2009/10/mf_optigenetics

http://www.nytimes.com/2011/05/17/science/17optics.html?_r=2&src=dayp