On the functional stucture of conditioned reflexes to serial stimuli in dogs

The functional structure of conditioned reflexes to a stimulus series has been studied. The serial stimulus consisted of a tone of 600 Hz, passive lifting of the right forepaw, and a puff of air directed at the eye, the latter component of the series being reinforced by food. Four dogs were wed. Objective registration of the effector manifestations to each component stimulus has shown that, during the elaboration of a conditioned alimentary reflex to the serial stimulus, conditioned connections are formed by each component with the alimentary center and by each preceding stimulus with all subsequent stimuli, irrespective of their position in the series. All excitation foci which function in the given stimulus set become interconnected. Direct connections of each stimulus component with the alimentary center are never inhibited. The multiplicity of duplicating direct connections and the presence of backward connections impart to composite reflexes the reliability and adaptive strength which is necessary for the formation of behavioral acts.