Our brains evolved to control a complex biological device: our body. As we are finding out today, many millennia of evolutionary tinkering has made the brain a surprisingly versatile and adaptive system, to the extent that it can learn to control devices that are radically different from our body. Brain-computer interfacing, the subject of this book, is a new interdisciplinary field that seeks to explore this idea by leveraging recent advances in neuroscience, signal processing, machine learning, and information technology.

The idea of brains controlling devices other than biological bodies has long been a staple of science-fiction novels and Hollywood movies. However, this idea is fast becoming a reality: in the past decade, rats have been trained to control the delivery of a reward to their mouths, monkeys have moved robotic arms, and humans have controlled cursors and robots, all directly through brain activity.

What aspects of neuroscience research have made these advances possible? What are the techniques in computing and machine learning that are allowing brains to control machines? What is the current state-of-the-art in brain-computer interfaces (BCIs)? What limitations still need to be overcome to make BCIs more commonplace and useful for day-to-day use? What are the ethical, moral, and societal implications of BCIs? These are some of the questions that this book addresses.