In the end of 1st and in the beginning of 2nd month at the child conditioned reflexes start to be formed. It means that the cortex of a brain starts to ripen and sense organs are differentiated.
Formation of conditioned reflexes at children is bound exclusively with medium surrounding them, a regimen, care of them. As at the child of a cell of a cortex of a brain are developed insufficiently again formed reflexes at it are fragile and easily die away under the influence of strong stimuluses. If the child gets to an unusual situation for it it quite often loses the got skills. Unusual borings and impressions cause an excessive boring of a cortex of a brain and diffusion of this boring that is expressed in anxiety of the child, whims, crying, cry or block, slackness and drowsiness.
The newborn child almost all time sleeps. It is absolutely helpless, does not hold a head, not in a condition to change position of the body, randomly moves arms and feet. To the beginning of 2nd month the child starts to smile, look after bright, large subjects. In process of development of the central nervous system and a musculation the child from 5-6 weeks starts to hold a head, and by 2 months holds it already well and, laying on a back, can lift it, in position on a stomach watches moving subjects and turns behind them a head. At this time the child starts to react on pull, a smile and conversation — briskly moves, smiles.
On 3rd month any movements of arms, a head and feet begin: the child turns a head on a sound; laying on a stomach and leaning against elbows, lifts a head and the top part of a trunk; turns from a back sideways; opens a mouth at breast or small bottle approach; pulls subjects in a mouth, loudly laughs.
In 4 months the child sits with support. Laying on a stomach, freely rises, leaning against palms, turns from a back on a stomach, a beret and keeps subjects; it has the emotional reactions expressing pleasure or displeasure.
On 5th month the child sits, if it support, learns mum, takes confident subjects and pulls them in a mouth.
On 6th month it can turn over from a stomach on a back, tries to grabble, crosses feet if it support, swings a toy.
After 6 months the child independently sits, shows interest to surrounding, expresses a fright and pleasure, starts to utter the first syllables — «ba», «ma» (in Russia).
In 7 months he pulls a small bottle in a mouth, rises on knees, clinging to a bed backrest, says repeated syllables — «ba-ba», «ma-ma» etc.
From 8 months the child independently sits down, rises, keeping for something, well costs, finds eyes a named subject.
In 9 months well creeps, goes behind a trolley at support for arms.
In 10 months rises without support, goes behind a trolley or a chair, and sometimes starts to go independently, says the first simple words, names tersely subjects, for example «av» (dog), «mu» (cow), distinguishes tender and severe tone.
In 11—12 months the majority of children starts to go independently though also it is not quite confident. To the extremity of 1st year the perception of external impressions is shown by means of conditioned-reflex communications. In a brain cortex there is a difficult work. The difficult nervous system is gradually formed. The child shows taste to meal, chooses toys.
In the beginning of 2nd year the child carries out simple commissions: «lift a pillow», «close a door» and so forth, expresses the disagreement, allocates from a considerable quantity of toys especially favourite, it is accustomed to neatness.