The first few years of a child's life are incredibly important when talking about development. Brain development includes physical as well as functional development inside your child's head. This development occurs in many stages as your child grows older. A major portion of developmental milestones are reached in the first six months of your baby's life.
In the first 6 months, your baby is learning about his/her immediate environment. This means there is going to be a lot of interaction with the surroundings, which is made possible by corresponding brain development. This interaction requires movement, which means there is going to be development in motor skills as well.
Between the ages of 1 and 2 months, babies learn to identify people in their surroundings. Very specifically, they first learn to identify their mother’s voice, smell, and feel, and later start responding to other people and stimuli like smiles (which they return) and the presence of new people. They tend to be curious about their environment and start developing the ability to control and stabilise their head movements, which means you'll probably find your baby turning his/her head to look at objects in his/her immediate surroundings. They tend to focus on objects that are closer to them and brighter in colour, as their vision is still developing and not very keen. When the object is out of sight, they tend to forget about its existence.
At around three months old, they can also anticipate certain events like knowing to lifting up their legs when they are placed on a changing table. This happens due to learning from previous experience.
At 4 months, they start reaching for objects and follow their movements. They try grasping objects and trying to understand them in their own way, such as putting it in their mouth, as they do not have the cognitive skills to understand them in any other way. They also learn to identify their own body parts when they see them and develop a sense of being an individual. They start wiggling their fingers and toes, and watch them move as they learn to manipulate their own bodies, developing a sense of individuality. In this stage, babies develop keener vision, whereby they can focus on objects that are further away, as well as sensory integration, which means they learn to associate smells and tastes with what they see.
At around 6 months, language skills begin to develop. You may hear your little one making babbling noises and random sounds. This is their attempt to replicate all that they hear. They also learn to recognize other people and familiar sounds, smells, and tastes. Babies acquire a skill called object permanence, which involves the awareness of objects even when they are not present within their range of vision.
Mental development is a very delicate and dynamic process, so try to ensure that you do all you can to facilitate and promote the development that your baby goes through. Being proactive and knowing what you can to do to help is always a positive step.