[Formation of chain reaction conditioned reflexes in chickens during different age periods]

The dynamics and mechanism of elaboration of chain instrumental reflexes were investigated in chicks at ontogenesis. It has been established that the older the chicks, the higher the rate of chains synthesis and the longer their preservation. The synthesis of chain conditioned reflexes has been observed since the age of two months, when the inhibitory process, concentration and equilibration of nervous processes are strengthened. The synthesis mechansims of motor reactions are similar in the birds of different ages: at first, the connections of each component of the chain stimulus with the motor reaction are elaborated, then they are replaced by successive connections between the first component of the chain and the whole chain of elaborated reactions. Long training of the chain reflex leads to the development of retardation inhibition and the appearance of a motor reaction to the last component of the chain reflex.