Functional MR imaging noninvasively provides images of the brain at work. For this reason, increasingly it is being used to gain insights into functional mechanisms of the normal and diseased brain. As a result, these insights no longer depend on single case studies with specific dysfunction following brain trauma. Using modern brain imaging techniques, it has been possible to visualize the organization of the visual, motor, sensory, and auditory cortex, and to localize these brain functions for presurgical planning.

Functional neuroimaging techniques have been employed primarily to study a variety of perceptual and cognitive processes in adult volunteers. Many questions relating to the development of the perceptual and cognitive systems are only beginning to be addressed. The noninvasive nature of functional MR imaging offers a real advantage over other techniques when dealing with children, yet providing a high spatial and temporal resolution. The link between neuronal activity, blood flow, and tissue oxygenation, which forms the basis of the signal change in fMR imaging, however, has to be further elucidated in the immature brain. The ability to link the emergence of function to the development of the corresponding central mechanism will allow new insights into normal perceptual and cognitive processes, leading to the clinical use of fMR imaging in children with congenital malformations and those with acquired disorders.