From newborn to "big baby" : 12 months
During the first weeks, any movement that your baby makes is involuntary and nothing that he does is on purpose. A newborn's behaviour is controlled by his brainstem. This is the most basic, bottom part of his brain, which has to do with his reflexes and bodily functions. A newborn baby doesn't yet use his big brain or cortex and therefore cannot think or do act intentionally! As he develops during the first year of life, his cortex will become more dominant and he will become more adept at moving his body parts at will. By the end of the first year of life your baby will be able to solve basic problems and make basic choices.
Most educators agree that the most healthy way to approach the "stimulation" of children during the formative years, is to focus on supporting the natural development of a child by creating the ideal circumstances for maximal development as they progressively develop step by step.
Here are some suggestions of things that you can do to support your child's development:
0-3 months: When you're feeding your baby, encourage him to gradually gain more control over his own body movements by placing your nipple at his cheek so that he can feel it and then practise turning his head and finding the nipple on his own, rather than placing the nipple in his mouth straight away. (He will initially turn his head in the direction of the nipple as part of a reflex reaction, but as he nears the age of 3 months, you will notice that the movement of his head becomes increasingly controlled he learns to turn his head at will!)
4-6 months: Support your child in an upright position and hang objects in places where she may be able to accidentally hit them as she swings her arms. (Hang these objects more the side than right in front of your baby she initially finds it easier to move her arms sideways.) At the age of 4-5 months your baby will have developed enough control over her upper body to enable her to reach out in the direction of an object in order to grasp it.
6-9 months: Most babies display the first sign of real intelligent behaviour when they solve their first problem at around 6-7 months of age. The most common problem, which is usually solved by babies of this age, is when a baby deliberately reaches out his hand to remove an obstacle that makes it hard for him to reach a favourite toy. You can encourage this development by placing an empty shoebox between your baby and a special toy make sure that you don't obstruct his view of the toy or else he may plainly forget about it!
9-12 months: Your child now learns to combine different actions to solve a problem. She will, for instance, crawl all the way to the other side of a room, come to a standstill, sit up and then remove a barrier to get to a favourite toy. Try to make use of everyday situations to create opportunities for her to solve problems. Instead of merely handing her a piece of food, show it to her and then hide it under a plastic cup. Praise her when she removes the cup to get to the food. (Repeat this little game often repetition is one of the most important keys to maximum intellectual development!)