M. R. COVIAN, C. TIMO-IARIA AND R. F. MARSEILLAN 



437 



IlG. S 



Disappearance of the negative component by previous 

 reticular stimulation (so msec, interval, i.s volts). 

 Time 200 cps. 



Fig. 6 

 Superimposed sweeps. Lower record: cortical evoked 

 potential. Upper record: cortical evoked potential 

 obtained 100 msec, after brain stem reticular stimu- 

 lation. 



