Not very long ago, the feasibility of mapping the distinguishable regions of the human brain in relation to their functional roles seemed remote. With the tremendous advances in neuroscience in the past two decades, however, the opportunity now exists to approach the integrated understanding of brain structure and functioning necessary to clarify the neurobiological basis of human thought and emotion and to discern the mechanisms that underlie sensory perception and locomotor functions. Many of the intricate anatomical connections of the brain are being defined in great detail. New capabilities have emerged to identify and describe the biochemical, molecular, and genetic mechanisms that determine brain structure and functions. The activity of the human brain during mental activity can be measured and visualized. It is even becoming possible to monitor simultaneously the activity of many neurons within complex neural networks during discrete behaviors. The challenge now is to establish a comprehensive initiative that will increase the ability of neuroscientists to make discoveries about the brain and to apply this knowledge to the many mental and neurological disorders that affect humankind.
The progress made in this area has occurred primarily through the concerted efforts of increasing numbers of individual investigators, working mostly in small groups on highly specific projects. The body of information gained through such efforts has grown in a piecemeal fashion; it has now reached a point of limitation, in terms of its usefulness, because the mass of information is so great and its dissemination so poorly coordinated that critical data are often difficult to recover and define. Indeed, this approach to neuroscience research, which was so successful in the past, may soon limit advances in the same way that a single surveyor who charts a field cannot hope to map a continent without a coordinated plan involving other mappers. A Brain Mapping Initiative could identify those aspects of information exchange infrastructure that are critical to addressing a broader goal, one that will include the advantages of single-investigator projects and yet also yield the benefits of a larger, coordinated program. The Brain Mapping Initiative is intended to subsume all the proposed aspects of a National Neural Circuitry Database outlined in the charge to this committee. It is also designed to express explicitly the goals of the proposed effort and reflect more adequately the complex of electronic and digital resources that will be required.
A consensus is emerging that the initial steps can now be taken toward the global task of understanding brain structure and functioning. The impact of digital computer technology began in the physical sciences three or four decades ago and led to such current large-scale efforts as the supercollider, space telescope, and interplanetary probes. In neuroscience, the increasing availability of new enabling technologies is likely to have similar, far-reaching impacts. The development of high-density memory chips and the latest generation of microprocessors provides a key stimulus to accelerated development of image analysis graphics and image manipulation—a set of capabilities known as visualization computing (McCormick et al., 1987). The emergence of parallel processing, scientific visualization workstations, and high-capacity digital communications may provide the technical support needed to conduct coordinated projects in neuroscience.
A comprehensive, coordinated effort to understand basic organizational patterns of brain connections needs to be undertaken. This effort should include a definition of the chemical identity of neuronal populations and a description of neuronal structure and neuronal circuit organization in each region in sufficient detail to clarify the computational processes involved. The pace of future advances in neuroscience will depend on critical choices, which need to be made now, regarding the handling of information to be gathered in the future. At issue is whether neuroscientists will embark on a large-scale effort to develop and integrate new forms of technology for acquiring and managing information.