E. A. ASRATYAN 



109 



without saying that this basic condition can be observed best when two 

 stimuh of ahnost equal physiological strength are combined (for example, 

 two 'nidifterent' stimuli, two unconditioned stimuli, or one 'indifferent' 

 and one unconditioned stimulus). This is also possible when two paired 

 stimuli are combined in a variable sequence. Such a combination of these 

 two factors can secure the formation and existence of double conditioned 



a 



p' 



F[G. 9 



I. Diagrammatic representation of a double conditioned connection 

 with equivalent components. 



II. Diagrammatic representation alter development of non-equivalence. 



connection with absolutely equivalent components (Fig. 9 I). But when 

 these paired stimuli are combined in a stereotyped sequence, the basic 

 condition is not fulhlled, which, in our opinion, leads to the development 

 of non-equivalence in the direct and reverse conditioned connections 

 (Fig. 9 II). We explain it in the following way. When the (P) and (S) 

 stimuli are applied in a stereotyped sequence, the central nervous structures 



