Brain-computer interfaces are opening new possibilities. Brain-computer interface (BCI) have the potential to give people with limited mobility increasing independence. In the future they might restore the power of speech to victims of severe strokes, as well as offer radical remedies for mental illness and Alzheimer’s disease. Yet BCIs can also be used in invasive ways that compromise individual freedom, such as an infallible lie detector and robotic super soldiers. Both technologies are based on the same scientific breakthroughs, and both take scientists one stop closer to decoding the brain. But scientists are finding that the brain does not give up its secrets easily...

Brain-computer interfaces are opening new possibilities. Brain-computer interface (BCI) have the potential to give people with limited mobility increasing independence. In the future they might restore the power of speech to victims of severe strokes, as well as offer radical remedies for mental illness and Alzheimer’s disease. Yet BCIs can also be used in invasive ways that compromise individual freedom, such as an infallible lie detector and robotic super soldiers. Both technologies are based on the same scientific breakthroughs, and both take scientists one stop closer to decoding the brain. But scientists are finding that the brain does not give up its secrets easily...