Its all known that giving your baby love and affection is the most important thing you can do to ensure his/her emotional development, sense of security, confidence and this fosters his mental development too. You have to judge them very keenly. As you start watching and understanding their minds, the approach towards them gets closer and vivid. Follow his gaze, his fingers where and what he is pointing, you will understand what he is interested in. Sometimes baby just need your arms, cuddle, kiss and sometimes they want to explore things on their own.
I try my best to read my baby's mind and it is interesting to get to know very closely, so that I can play with him and simultaneously I find it a learning approach for him. I watch him when he plays with his mobile toy hanging over his cot and I just don't leave him alone, sometimes I watch him what he is doing and how he is enjoying, then one day I tied his one leg with soft saturn ribbon( very lightly) so that he can see those toys in the mobile spinning around when he moves his leg. This helps them to do things on his own which is quite interesting. Their are lots of things which I find very helpful to make him play and at the same time to make him learn as well. I make different facial expressions or try to amuse him with different colourful toys, music so that he could get to know about different things and he can learn. I think babies minds are very prominent and its a precious gift given to parents for its safe keeping and to nurture it, so I repeat three-four same words(like good morning, good night, clapping, dog) or sing poems( twinkle twinkle, baba blacksheep, chanda mama, machhli jal ki) daily with action and I found all these very helpful even if he is crying, screaming, this deviates his mind and he enjoys. Sometimes what I do is: I only sing without action and all of a sudden he starts looking for action( that am not doing as I always do) Some of these moments with him is full of enjoyment for both of us.
Some of these actions with him I find very approachable. So we should not only rely on nature to stimulate it but we as a caregiver, nurture them properly which is stimulating and enriching :)