The Computer and the Brain (The Silliman Memorial Lectures Series)
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In this classic work, one of the greatest mathematicians of the twentieth century explores the analogies between computing machines and the living human brain. John von Neumann, whose many contributions to science, mathematics, and engineering include the basic organizational framework at the heart of today's computers, concludes that the brain operates both digitally and analogically, but also has its own peculiar statistical language.
In his foreword to this new edition, Ray Kurzweil, a futurist famous in part for his own reflections on the relationship between technology and intelligence, places von Neumann’s work in a historical context and shows how it remains relevant today.
for similar machines all over the country. Some of the basic principles developed in the JONIAC are used even today in the fastest and most modern calculators. To design the machine, Johnny and his co-workers tried to imitate some of the known operations of the live brain. This is the aspect which led him to study neurology, to seek out men in the fields of neurology and psychiatry, to attend many meetings on these subjects, and, eventually, to give lectures to such groups on the possibilities of
division these rules have a quite complex logical character. (This may be obscured by our long and almost instinctive familiarity with them, but if one forces oneself to state them fully, the degree of their complexity becomes apparent.) Logical Control Beyond the capability to execute the basic operations singly, a computing machine must be able to perform them according to the sequence—or rather, the logical pattern—in which they generate the solution of the mathematical problem that is
description contains some idealizations and simplifications, which will be discussed subsequently. Once these are taken into account, the digital character no longer stands out quite so clearly and unequivocally. Nevertheless, the traits emphasized in the above are the primarily conspicuous ones. It seems proper, therefore, to begin the discussion as I did here, by stressing the digital character of the nervous system. Time Characteristics of Nerve Response, Fatigue, and Recovery Before
108 to 109 —the same factors that appeared above with respect to volume requirements. Summary of Comparisons Summing up all of this, it appears that the relevant comparison-factor with regard to size is about 108 to 109 in favor of the natural componentry versus the artificial one. This factor is obtained from the cube of a linear comparison, as well as by a volume-comparison and an energy-dissipation comparison. Against this there is a factor of about 104 to 105 on speed in favor of the
of cycles (the period of time necessary for neural circuits to consider new inputs). Von Neumann correctly concludes that the brain’s remarkable powers come from the ten billion neurons being able to process information all at the same time. Recent advances in reverse engineering the visual cortex have confirmed that we make sophisticated visual judgments in only three or four neural cycles. There is considerable plasticity in the brain, which enables us to learn. But there is far greater