258 Information Storage and Neural Control 



Figure 9A shows the average response waveform obtained from 

 the mesencephaHc reticular formation at this stage of training 

 during correct performance to a four per second flicker. 



Figure 9B sliows the average response waveform obtained from the 

 mesencephalic reticular formation during generalization to the ten 

 per second flicker. Note the highly complex and irregular waveform. 



Figure 9C shows the average response waveform obtained from 

 the mesencephalic reticular formation during correct performance 

 to the ten per second flicker following differentiation. In contrast 

 to Figure 9B, note the increased simplicity and regularity of the 

 waveform. 



Figure 9D shows the fit to the generalization waveform of the 

 interference pattern which can be obtained by arbitrary algebraic 

 addition or subtraction of the two waveforms elicited from the 

 reticular formation during behaviorally appropriate performance 

 to four per second and ten per second flicker, as shown in Figures 

 9A and 9C. Again, that manipulation (10 +4 or 10 — 4) which 

 gave the better fit was selected. 



Thus, one can synthesize interference patterns from average 

 response waveforms computed during behaviorally appropriate 

 response to two different stimuli and can approximate closely the 

 actual average response waveform obtained when an animal re- 

 sponds to one of these stimuli by a previously learned behavior 

 appropriate to the other. This demonstration provides striking 

 evidence in support of the suggestion that the neural response to 

 the ten per second stimulus actually presented was modified during 

 generalization by an electrical influence identical with the response 

 to the four per second conditioned stimulus repeatedly experienced 

 during the earlier establishment of the conditioned response. At 

 the moment I see no way to evade the conclusion that the conse- 

 quence of experience with the four per second flicker during learn- 

 ing somehow caused a modification of neural structure which there- 

 by gained the capacity to generate electrical activity like that which 

 established it. These data support the interpretation that such 

 patterns of potentials are of functional significance and are closely 

 related to the actual processing of information. 



At our present stage of knowledge, no mechanisms come to mind 

 which might serve to generate and mediate an interaction of the 



