“…The study of the conditioned reflexes in children was first attempted by a pupil of Pavlov, Krasnogorsky (7). He, as well as Peiper and Helmreich (8), who uses Krasnogorsky's data, reported that their subjects during the first two to six months of life did not form any conditioned reflexes and, therefore, this observation is considered evidence of a lack of functional activity of the cortex during those months. According to Krasnogorsky, however, it is possible that the first conditioned reflexes may be formed during the fourth or fifth month of life.…”