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Information Storage and Neural Control 



A B 



Fig. 4. "Generalization and differentiation" in single unit responses. During the 

 passage of anodal current (A & B) the critical tone (A) and a single presentation 

 of the indifferent tone (B) were equally effective in provoking high frequency 

 bursts. Twenty minutes after cessation of current flow (C & D) the critical tone 

 (C) continued to elicit the response while the indifferent tone (D) did not. Forty 

 minutes after discontinuing polarization (E & F) neither signal produced any 

 change in unit discharge frequency. Calibration: 2 millivolts and 500 milli- 

 seconds (40). 



occurred with each stimulation (Fig. 4A). Another member of 

 the habituated stimulus group (500 cycle per second tone) was 

 presented once in the polarization period and also elicited unit 

 discharge (Fig. 4B). The current was then discontinued and in 

 the following twenty minutes the 200 cycle per second tone con- 

 sistently provoked unit activity (Fig. 4G) while the 500 cycle 



