In the first demonstration of human brain-to-brain control, a scientist wearing an electrical brain-signal reading cap triggered motion in his colleague across campus [1]. While research on brain–machine interfacing has been going on for years, this recent demonstration represents an impressive signal of how advanced technology has become. Using electrical brain recordings and a form of magnetic stimulation, one researcher sent a brain signal to another on the other side of the University of Washington campus, causing the recipient’s finger to move on a keyboard. Similarly, other researchers have demonstrated brain-to-brain communication between two rats, or between a human and a rat.

The technologies used by the researchers for recording and stimulating the brain are both well known. Electroencephalography (EEG) is routinely used by clinicians and researchers to record brain activity non-invasively from the scalp and is discussed in the first chapter of this part of the book. Transcranial magnetic stimulation, on the other hand, is a non-invasive way of delivering stimulation to the brain to elicit a response. In the experiment mentioned above, the stimulating magnetic coil was placed directly over the brain region that controls a person’s right hand. By activating these neurons, the stimulation “convinced” the brain that it needed to move the right hand.