THE COMPUTER IN BIOLOGICAL RESEARCH 309 



be in man's understanding of his control biophysics is hard to predict; but 

 today it is an exciting avenue by which people are approaching the subject. 



Quantitative description of these ideas is developing rapidly, as an inte- 

 gral part of missile and space technology, in which man has control of the 

 characteristics of the components, through design. The neuronal circuit, 

 with switches (synapses) (Figure 1 1-4), is about a billion times smaller than 

 the vacuum tube circuit, and perhaps about a million times smaller than the 

 transistor circuit, and a thousand times smaller than thin-film, solid-state 

 circuits now in the research stage. The neuron operates on the movements of 

 ions rather than electrons, and much has yet to be learned about its opera- 

 tion. Further, the number of "components" in the brain is about a million 

 times the number in the largest of today's computers. Therefore it is certain 

 that quantitative description of the control circuitry of the central nervous 

 system is a long way off ! 



Inherent in all these systems is an error, or noise, or background, above 

 which the information, the signal, must be distinguished. It is easy to build 

 an analog computer with a precision of about 1/1000; harder to build one 

 with 1/10,000: and impossible to build one with 1/100,000 or less because 

 machining of parts and electrical measurements cannot be made with 

 greater precision. By contrast, simply increasing the number of components 

 can increase the precision of the digital machine to 1/10,000,000,000, if it is 

 desirable and practicable. 



Since the central nervous system operates with about 10,000,000,000 com- 

 ponents, or neurons, and since it has both digital and analog facility, the 

 problem of understanding this system is obviously not an easy one. Al- 

 though the normal operation of this system is wondrous enough, errors in 

 "switching" can give rise to a whole host of disorders — problems not only 

 for the neurologist but also some that are likely to keep the psychologist and 

 psychiatrist in business for a long time to come. 



THE COMPUTER IN BIOLOGICAL RESEARCH 



As a tool in medical research, the computer can do many useful things. 

 The day may not be too far off, for instance, when medical clinics will be 

 equipped with general diagnostic machines which, when properly fed with 

 factual information on symptoms, will not only punch out a statement of 

 what the possible diseases are but also arrange them in order (with the most 

 probable one at the top) and state what further examinations can most 

 profitably be done to save the time of the physician and the money of the 

 patient. The machine-processing of records and accounts in clinics and hos- 

 pitals is closer still. With us now is the use of computational machinery to 

 help the researcher in studies of those biophysical problems in which rea- 

 sonably precise quantitative measurement is possible. Rapidly maturing as 



