24 Information Storage and Neural Control 



technique of EEG analysis. The objective of this investigation was 

 to evaluate the information handling capability of zero crossing 

 analysis as compared to frequency analysis. Conventional fre- 

 quency analyzers were compared on an information theoretical 

 basis with the zero crossing analyzers which Dr. Burch of Baylor 

 is using in his EEG research. The particular problem treated was 

 concerned with how much information is abstracted by an analyzer 

 which processes only time point data associated with zero crossings 

 of the record and the time positions of its peaks and points of inflec- 

 tion. Knowing the time resolution which could be achieved with 

 an analyzer of this type, it was possible to establish the frequency 

 resolution that would be required of a frequency analyzer in order 

 to provide the same amount of information. I will admit that 

 this does not add much understanding of neurophysiological 

 processes, but it does give a basis for some engineering decisions 

 relative to whether one type is more effective in abstracting 

 information than another type. It turned out that the resolution 

 that could be achieved with practical period analyzers was much 

 greater than that which could be achieved with practical fre- 

 quency analyzers. 



Kellaway: Would it matter if it were a physiological signal? 

 The signal that you are using could be anything, could it not? 



Saltzberg: The signal could well be anything. However, what 

 one would like to achieve is a signal representation and a cor- 

 responding form of analysis emphasizing the physiological effects. 

 For example, if one attempts to extract information by analyzing 

 the coefficients of a Fourier series, the problem may be impossible 

 because the interesting infoi^mation is contained in small per- 

 turbations in many amplitudes of many frequencies. Since similar 

 small perturbations can be caused by noise, the presence of noise 

 would invalidate any physiological correlates being sought. How- 

 ever, if some other parameter associated with a different signal 

 representation were measured, it is possible that physiological 

 effects could cause this parameter to change grossly, which would 

 lead to a higher probability of valid pliysiological correlates. 



Max E. Valentinuzzi (Atlanta, Georgia): Gan you say any- 

 tliing about the relation between information and organization? 

 Gan we say that these two words are equivalent? You have dealt 



