204 BRAIN MECHANISMS AND LEARNING 



synthesis stage, like the subsequent formation of the effector apparatus of 

 the conditioned reaction itself However, it forms, in large measure as an 

 independent, physiological formation and has, as we shall see later, a 

 special afferent significance. 



hi its physiological content this apparatus consists essentially of the 

 afferent excitations which in their totality reflect precisely the sum of 

 afferent excitations that must enter the cerebral cortex only at the end of 

 the reflex action. It follows that the acceptor of action, as an afferent 

 reflection of the results of future action, is a physiological apparatus of 

 so-called 'anticipation'. 



The tremendous importance of this apparatus in the behaviour of 

 animals consists primarily in the fact that forming immediately after the 

 end of the afferent synthesis stage it considerably forestalls the process of 

 formation of the reflex action as well as the completion of this action. 



The acceptor of action makes its appearance so soon after the end of the 

 afferent synthesis that it may be argued that this apparatus is a direct and 

 immediate result of precisely the afferent synthesis stage. 



From a psychological point of view this moment, i.e. the end of the 

 afferent synthesis corresponds to the emergence of the 'idea', 'intention' or 

 'aim' to perform the given action. 



I believe it is necessary to observe at this point that the various reports 

 that I have pubhshed on the physiological mechanisms of this stage in the 

 development of conditioned reflex actions, have shown that many 

 investigators do not as yet adequately understand that m a psychological 

 sense the emergence of an 'intention' to perform some action /'.■; an abso- 

 lutely indispensable stage which antedates the action itself and that, con- 

 sequently, we, physiologists of the nervous system and higher nervous 

 activity, must strive to analyse the physiological correlates of this 'intention'. 



The physiological content of this apparatus consists of the entire past 

 afferent experience of the animal or man concretely related to the given 

 behaviour pattern. Basically it is a certain integration of the afferent 

 impulses w hich arise from the results of some reflex action or act of 

 behaviour. 



For example, grasping a pitcher of water is connected with the reception 

 of a series of aftcrcnt influences of a varying modality. 



Our brain receives specific tactile impulses reflecting the form and 

 mechanical properties of the pitcher, temperature impulses, kmaesthetic 

 impulses suggesting weight and, consequently the fact that the pitcher is 

 filleci with water, etc. The impulses also include a visual afferentation 

 suggesting the movement of the hand towards the pitcher. 



