280 Information Storage and Neural Control 



with a system which uses a different language for each kind of 

 message. I cannot assert that information about diverse events 

 is necessarily coded in the same way, but I would prefer to test 

 that hypothesis rather than to accept a doctrine of specific message 

 languages. I have presented evidence which suggests that the 

 temporal pattern of macropotentials may be related to the coding 

 of information about flicker frequency. Were I convinced that 

 this were the code for this carefully specified stimulus, I would 

 be inclined to suggest temporal pattern of potential as the most 

 probable code for other sorts of stimuli. 



I would like to take advantage of this opportunity to ask you 

 a question about your paper this morning, which is not unrelated. 

 Certain aspects of the model which is implicit in what you said 

 seem to pose appreciable difficulties. If I understand you, you 

 suggested a memory based on the specification of protein sequences 

 by ribonucleic acid. You did not touch on the question of how 

 to obtain a readout from this memory. To use your terms, are you 

 sure that such a memory would be more efficient than a memory 

 which would operate as follows: The spatio-temporal distribution 

 of activity caused by a stimulus in an extensively interconnected 

 network of cells is such that, due to local micro-environments, 

 characteristic interspike intervals, fiber diameters and distances 

 between elements, etc., there is some population of cells for which 

 re-entrant pathways exist such that a reverberation can be sus- 

 tained to a given stimulus configuration. Maintaining this rever- 

 beration for a sufficient time, which might be the duration of the 

 consolidation period, might accomplish a change in macro- 

 molecular synthesis. As the average intracellular electrolyte con- 

 centration was altered by sustained reverberatory activity, a 

 change might occur in the carbon-to-carbon bond angle of RNA, 

 thus altering the distance between purine and pyrimidine bases. 

 Such changes in the spacing of the template would alter the amino 

 acid species which would fit in that place. The concentration of 

 the appropriate amino acid in the environment would determine 

 the probability that the appropriate fit would be made. The rate 

 of assemblage of a protein would depend on the achievement of 

 the appropriate concatenation of amino acids on the template. 

 Therefore, since the concentrations of various amino acids in the 



