ABSTRACT
A scientific theory of intelligence, in the true sense of the term, cannot be translated directly into a prescription for practice. In any case, a real theory of intelligence does not yet exist. If it did exist, it would describe the anatomical, neural, and chemical processes in the brain that govern the types of behavior that are claimed to characterize intelligence. The major aim of present-day cognitive neuroscience is to achieve this kind of understanding of how brain mechanisms produce intelligent behavior, but as yet we have no comprehensive account of how the brain does this. After all, the human brain is the most complex structure known to modern science, and the technology needed for probing the living brain in action, such as the measurement of evoked electrical potentials by electroencephalography, or of the metabolic rates in specific regions and structures of the brain by positron emission tomography (PET) scan, or mapping localized functions by magnetic resonance imaging (MRI), are all of fairly recent origin in the history of scientific instrumentation. Hence, scientists are just beginning to investigate how the living brain performs the cognitive functions subsumed under the term intelligence.
