Advanced application of magnetic resonance imaging in human brain science.

Magnetic resonance imaging (MRI) has revolutionized the practical demands of clinical neurology. This technology promises now to advance neurology in theoretical and applied realms of fundamental human brain science. We emphasize here two domains in which these advances will occur. The first is volumetric morphometry of the human brain. With MRI the multiple levels of processing of the brain may be characterized in terms of their absolute volumes and their relative sizes, perspectives indispensable for our understanding of the development and operation of neural systems. Volumetric morphometry also promises substantial increases in the specificity and sensitivity of neurological diagnosis, particularly where applied to disorders where structural abnormalities will be reflected only in volumetric abnormalities. The second direction of advance considered here is application of MRI in cortical mapping in support of cognitive neuroscience. In this application MRI provides means to map at high resolution the distribution of subcomponents of neural systems activated by behavioral paradigms. This line of investigation will carry forward rapidly our understanding of how the information processing algorithms of the brain are mapped upon the coordinates of the various gray matter structures of the brain. Among the practical consequences of this application will be a reasoned design of surgical field in tumor and epilepsy surgery.