p. K. ANOKHIN 209 



when the child opens the box. However, if a (laiiity of another quality is 

 imperceptibly placed in the box, upon opening the box the child imme- 

 diately develops a reaction of 'surprise' ('What is it?', according to Pavlov) 

 which occurs with different variations depending on a number of condi- 

 tions. The child may carefully examine the box from all sides, shake it 

 in the hope of receiving the expected reini(n-ceinent, etc. It is perfectly 

 clear that all these actions are a direct result ot the lack of correspondence 

 between tlie fixed afferent excitations in the form of the acceptor of actio)! and the 

 afferent iujiitences coniino to the central nerrons system from the inadequate 

 appearance of the nen' dainty when the box is opened. 



The third way of proving the emergence of afferent excitations in the 

 acceptor of action forestalling the formation of the action itself is the 

 electroencephalographic method. As stated previously the systems of 

 afferent excitations forming part of the acceptor of action are mobilized 

 much more rapidly than the effector part of action. At times, a very com- 

 plex reflex action is formed. It follows that the ascertainment of the prepara- 

 tory excitations in the area of the cerebral cortex, ndiicli must, in the future, 

 receive the return afferentation from the results of the action, should become one 

 of the methods of studying the physiological mechanisms of tlie acceptor 

 of action. 



A typical example of the anticipatory spread of excitations over the 

 cerebral cortex is the generally known, so-called, electroencephalographic 

 'conditioned reflex' which manifests itself when sound and light are 

 combined. As is well known, after a number of such combinations 

 the sound alone causes a desynchronization of the a-rhythm in the 

 occipital area of the cortex before the appearance of the lioht. Here the 

 sound sets off a chain of excitations in the cerebral cortex, which spreading 

 rapidly reaches the elements in the visual cortex that will not receive 

 adequate visual excitation from the periphery until a few seconds later 

 (Jasper, 1937; Livanov, 1937; Karazina, 1957; and many others). 



Any acceptor of action for any, even very complex acts of behaviour, is 

 formed absolutely according to the same type. Any act of behaviour is 

 represented in the cortex by the development of an uninterrupted chain of 

 afferent excitations received from the individual stages of this act to the 

 final reinforcing factor inclusive. It is precisely this chain of traces of the 

 past afferent excitations that is a peculiar 'conductor' for the rapid spread 

 of the excitations from the conditioned stimulus to the system of excita- 

 tions udiich is the afferent reflection of the results of the as yet forthcomino 

 action. 



Exaniples of such a spread of the afferent excitations may now be 



