The Defense Department's research arm is working on a project that connects human operators' brains to the systems they're controlling-and vice versa.The idea of humans controlling machines with their minds has spun off sci-fi blockbusters like "Pacific Rim" and entire subgenres of foreign film, but while today skyscraper-sized fighting robots exist only on the big screen, the Pentagon is building technology that could one day make them a reality.Today, the Defense Advanced Research Projects Agency is selecting teams to develop aThe Next-Generation Non-Surgical Neurotechnology , or N3, program aims to combine the speed and processing power of computers with humans' ability to adapt to complex situations, DARPA said. In other words, the technology would let people control, feel and interact with a remote machine as though it were a part of their own body."From the first time a human carved a rock into a blade or formed a spear, humans have been creating tools to help them interact with the world around them," said Al Emondi, the program manager at DARPA's Biological Technologies Office. "The tools we use have grown more sophisticated over time ... but these still require some form of physical control interface-touch, motion or voice. What neural interfaces promise is a richer, more powerful and more natural experience in which our brains effectively become the tool."DARPA began studying interactions between humans and machines in the 1960s, and while technology that merges the two may sound far-fetched, the organization already proved it's possible.Through its Revolutionizing Prosthetics program, DARPA created a prosthetic limb that disabled veterans can control using an electrode implanted in their brain. The system gives users "near-natural" arm and hand motion while transmitting signals that mirror a sense of touch back to their brain.NowThe N3 program is divided into two tracks: non-invasive interfaces that sit completely outside the body, and minutely invasive interfaces that could require users to ingest different chemical compounds to help external sensors read their brain activity. In both tracks, technologies must be "bidirectional," meaning they can read brain activity and also write new information back to the user.While those capabilities might fuel conspiracy theories about government mind-reading and mind-control, Emondi told Nextgov that won't be the case-scientists are only beginning to figure out how the brain's 100 billion neurons interact, so controlling those interactions is next to impossible. Instead, he said it's better to think of N3 technology as means to use to a computer or smartphone without a mouse, keyboard or touch screen.The program is solely focused on designing an interface for humans to connect with technology, not the technology itself, but according to Emondi, the use cases will likely be more high stakes than controlling prosthetic limbs.He theorized the interface could be used to help a pilot coordinate a fleet of drones with their thoughts or troops to control a remotely deployed robot by using their brain's motor signals. He added cybersecurity specialists could even connect to the system to monitor different parts of a computer network with their physical bodies.Depending on how the interface is designed, thatStimulating different neurons create different sensations in the body, said Emondi, and participating teams must decide how their device will transmit signals back to the brain.Given the intensely personal nature of the technology, DARPA is requiring designs to comply with a number of health and safety requirements, and also address any potential cybersecurity concerns. While today the project's biggest ethical questions relate to safety and risk of testing, "if N3 is successful," Emondi said, "I anticipate we could face questions related to agency, autonomy and the experience of information being communicated to a user.""We don't think about N3 technology as simply a new way to fly a plane or to talk to a computer, but as tool for actual human-machine teaming," Emondi said. "As we approach a future in which increasingly autonomous systems will play a greater role in military operations, neural interface technology can help warfighters build a more intuitive interaction with these systems."Participating teams will have four years to create a working neural interface.