The primate studies on localization of brain function have been extended to humans by using a new research tool called positron emission transaxial tomography (PETT). (For more on PETT, see article on next page.) The main brain functions examined so far have been vision, hearing and, to a lesser extent, touch and muscle movement.
The most extensive studies in humans (so far about 30 volunteers) have been done by a group headed by Martin Reivich, MD, professor of neurology and director of the cerebrovascular research center at the University of Pennsylvania School of Medicine, Philadelphia, in collaboration with Albert Wolf, PhD, of the Brookhaven National Laboratory, Upton, NY.
The basic experimental paradigm is to have a person look at a spot of light in the center of a large hemispherical bubble that has one dark half and one illuminated half. A stimulus—a card with variously oriented black lines—is presented in