274 



BRAIN MECHANISMS AND LEARNING 



EFFECTS ON POT. EV. BY SS ON CSC 



REDUCTION 

 SS VOLTAGE 



W*V*&^V'^^'*^ 



NOVEL TONE 



CRASH 



1 



COND T 



sil , 



Fig. 6 

 comparison of modifications produced in evoked poten- 

 TIALS BY DIFFERENT EEG 'aROUSAl' INDUCING INFLUENCES (I). 



'Masking' effects of T were comparable in each instance to 

 those of SS voltage reduction (from 8 to 5 volts, top line), 

 first application o"f tone (NOVEL TONE NT, second line) 

 and application of intense sound (CRASH CR, third line); 

 a conditioned tone (COND. T. CT, fourth line) was less 

 effective. 



