At first the computer game looks awfully easy for an eight-year-old--like something out of the Stone Age of arcades in the 1980s. A red triangle "arrow" appears on the monitor's blue screen, and then the nose of a cartoon airplane glides into view from the left. If the arrow points upward, Ben must make the plane climb. When he succeeds, a spiky yellow sun beams.
A second glance shows that all is not as it seems. For one thing, Ben has no joystick. Instead several electrodes glued to the boy's face and to the skin under his hair let him pilot the plane by thought alone.
Ben is participating in an experiment. The point is to take advantage of neurofeedback--a training tool based on electroencephalography (EEG), the measurement of changes in electrical potential that accompany any brain activity. Electrodes conduct the brain signals, which are then processed by a computer program and fed into the game. The plane's motion thus reveals to Ben what just happened in his head. "Through the feedback the children are supposed to learn to deliberately control certain parameters of their brain activity," explains psychologist Ulrike Leins of the University Hospital for Psychiatry and Psychotherapy at the University of Tuebingen in Germany.
Such "mind reading" offers many possible applications. It has, for instance, enabled "locked-in" patients--who cannot speak or gesture--to communicate with caregivers. By controlling their brain waves, the patients manipulate letters and words on a computer screen. Practice with neurofeedback may also benefit those who suffer from epilepsy, attention deficits, depression and other debilitating mental disorders. The experimental therapy, also called EEG biofeedback, may even help rev up healthy brains, improving cognitive performance.
From Bio to Neuro
The technique is a high-tech twist on biofeedback--a method long used to treat stress-related disorders. In biofeedback, people see or hear physiological measurements that can indicate stress, such as increases in blood pressure, heart rate or muscle tension. Receiving such information from monitoring devices makes normally undetectable body functions accessible for conscious regulation. A person can realize from listening to his racing pulse, for example, that he is under strain and then learn to bring his heart rate down purposely.
The first clues that brain waves could be altered intentionally came nearly four decades ago. In the late 1960s sleep researcher M. Barry Sterman learned something interesting while tracking the EEGs of cats. He found a previously unknown pattern of brain waves with frequencies between 12 and 15 hertz (Hz), or cycles per second, in a part of the brain called the sensorimotor cortex. Sterman, now professor emeritus at the University of California, Los Angeles, dubbed this pattern the sensorimotor rhythm, or SMR. SMR was always present, he learned, in relaxed and awake felines. When he rewarded the animals at those moments with snacks, they began to produce stronger SMRs. Through this conditioning experiment, Sterman demonstrated that it is possible to change one's own brain waves deliberately.
The researcher might well not have followed up on this discovery. But at roughly the same time, he received a request from the U.S. Air Force, which wanted him to test the potential cognitive effects of exposure to monomethylhydrazine, a substance used in some rocket fuels and known to cause seizures. Sterman injected the chemical into cats. About an hour afterward, most of them suffered a seizure. In a few of the subjects, however, the seizure's onset occurred considerably later than usual; three others escaped the convulsions entirely. Seeking an answer for the resistance, Sterman examined his experimental protocol. He observed that the resilient cats had one thing in common: they had previously been involved in his conditioning tests. Could their ability to control their SMR waves have been a factor?