Hominization of the brain is the evolution of the human brain traits that discriminate the genus Homo from its primate ancestors.Evolution of the brain started with the reflex brains in vertebrate animals as such the fish, but the brain functions of volition, the autonomic nervous system and dexterous control are mammalian. Thinking and emoting are functions demanding enormous brain capacity. An adaptation was made by converting the right-lefi duplicate brains into a huge single brain.In the human's cognition, one of the characteristics of hominization is an evolution,ary hierarchy of the information centers: Its ascending limbs consist of (1) the primary sensory cortices, (2) higher order sensory cortical areas and (3) the association cortices, and its descending limbs consist of (4) higher order motor cortices that feed (5) the primary motor cortices.W e may intervene in the processing, especially that taking place in the association cortices: we monitor and manipulate the processing by retrieving, modifying, storing or replaying the informational material: thinking whatever at all. Here we have a virtual experience. This ability expands to processing even in the substantial absence of any perceivable objects, enabling us to communicate with verbal words and with symbols and letters, too.Pavlov's experiment on the conditioned reflex reveals one of the ways in which the perception of a n object can be made specifically meaningful. An act becomes so closely intermeshed with emotion and volition that you will have pleasure in doing it. This ability is furthered by the so-called crystalization of Stendhal: it is a way of magification. W e may apprehend the critical significance of a matter or indulge in daydreams. The activity of the brain is characterized as "ondemand" rather than "full-time" functioning, and so is its metabolism. The cerebral arterial system has a special device for prompt on-demand delivery (Okuyama, 0-8186-8084-9/97 $10.00 0 1997 IEEE 1992). This saves energy and prevents oxidative vascular damage as well.Computer technology first was developed so as t o substitute for human manual writing and computation, but it soon turned out also to be useful in increasing human cognitive power: e.g., in an improvement of our density resolution by digital coloration (Okuyama et al. 1979).W e can train ourselves so as to better operate computers, in an adaptation of the human being to the machinery. W e can transform ourselves into wonderful users when interest and pleasure grow in operating computers even without any profits from such growth.However, shall we be %ensed" and "cognized" when we engage in selected jobs and our ever-changing intention is deciphered by the computers? If yes, will the computers manipulate and control machinery and fulfill jobs on our behalf? Or, are we to evolve ourselves t o the needs of the computer technology? If so, can we efficiently monitor our own errors and have the errors promptly corrected?