Information Storage in Nerve Cells 207 



A B c D 



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Fig. 15. EEG tracings and conditioned response performed during various con- 

 ditions of polarization. A. — cathodal polarization of motor corte.x. B. — anodal 

 (motor). C— cathodal (visual). D. — anodal (visual). Calibration: 50 microvolts 

 and one second. Explanation in text. 



polarization. On the other hand, during anodal polarization of 

 the motor cortex (Fig. 15B) the latency of CR was very short and 

 the amplitude of photic "driving" was much reduced. A similar 

 EEG pattern was observed during application of cathodal current 

 to the visual areas (Fig. 15C). Reversing the direction of current 

 flow (Fig. 15D) resulted in considerable augmentation of photic 

 "driving." 



A summary of data in critical training sessions is given in Table I. 

 The number of observations and the median and range for the 

 number of conditioned responses per session are listed for the 

 following conditions: 



Polarization of ears; motor cortex, anodal, cathodal; visual cortex, 

 anodal, cathodal; session before anodal and cathodal (visual) 

 polarization; session after cathodal (visual) polarization; session 

 after anodal (visual) polarization; session after break in training. 



Statistical analysis of these findings leads to the following con- 

 clusions: 



1) Performance under tlie condition of visual cathodal polari- 

 zation differs from that of visual anodal, motor anodal 

 and cathodal and ear (anodal and cathodal) at better 

 than the 1 per cent level of confidence. 



