Today in 1948, John von Neumann spoke at the Hixon Symposium at Caltech about ”The General and Logical Theory of Automata,” “a general outline of the ideas and trends in the application of artificial automata theory to living organisms and particularly the human central nervous system.”
Working as a consultant to the ENIAC project, the first electronic general-purpose computer, mathematician John von Neumann circulated in June 1945 a report defining the stored-program computer architecture, which has served to this day as the basic design for all modern computers.
Using terms taken from biology, von Neumann described the various parts of the computer as “organs,” the building blocks of computer logic as “neurons,” and the internal storage unit as “memory.” While von Neumann thought that the brain was a computer, he allowed that it was a complex one, and that simple comparisons ignored “the more complicated aspects of neuron functioning.” In the 1948 lecture and subsequent work, von Neumann stressed the complexity of the human brain and described its processes as both digital (similar to a modern computer) and analog.
After von Neumann’s passing in 1957, Claude Shannon wrote in “Von Neumann’s contributions to automata theory”:
A field of great interest to von Neumann was that of the relation between the central nervous system and modern large-scale computers. His Hixon Symposium paper relates to this theme as well as to the problem of self-reproducing machines. More particularly, the Silliman Memorial Lectures (which he prepared but was unable to deliver) are largely concerned with this comparison.
While realizing the similarities between computers and nerve-nets, von Neumann was also clearly aware of and often emphasized the many important differences. At the surface level there are obvious differences in order of magnitude of the number and size of components and of their speed of operation. The neurons of a brain are much slower than artificial counterparts—transistors or vacuum tubes, but on the other hand they are much smaller, dissipate less power and there are many orders of magnitude more of them than in the largest computers.
At a deeper level of comparison von Neumann stresses the differences in logical organization that must exist in the two cases. In part, these differences are implied by the difference in the kind of problem involved, "the logical depth," or the number of elementary operations that must be done in sequence to arrive at a solution. With computers, this logical depth may reach numbers like 107 or more because of the somewhat artificial and serial method of solving certain problems. The brain presumably, with more and slower components, operates on a more parallel basis with less logical depth and further, the problems it confronts are much less of the sequential calculation variety.