[Interaction of instrumental habits in the sphere of heterogeneous conditioned reflex activity]

The phenomenon of interference of one reflex with another was observed in dogs during performance of heterogeneous instrumental conditioned reflexes elicited in a stereotype order. When alimentary conditioned reflexes involving the right-leg movement, were elaborated before the defensive ones involving the left fore-leg movement, then manifestation of the second reflex was preceded by a movement with the right leg. When the elaboration of conditioned reflexes started with defensive reflexes, the opposite was observed: before performing the alimentary reflex, the dogs lifted first the left fore-leg connected with the defensive reflex, and then the right one. Inertia of the nervous mechanism underlying this phenomenon, is based on a tonic increase in the excitability of the corresponding structures.