Experiences are the key to the development of Pattern Recognition.
Because Pattern Recognition is cultural, we know that the key is experiences.
Considering the complexity of letters, their importance in our children's lives, and the need to recognize them relatively early (many school programs have reading programs for five and six year olds), it would seem to me that we would want to provide for our children as many experiences as we can to develop the neural infra structure to easily recognize these basic patters.
This translates in to having many "things" available for children to explore and interact with as babies. Soft round cloth and rubber balls, blocks of various shapes and sizes, and many other objects that can be grasped, mouthed and manipulated are the tools that the child will use to build the perceptual skills to recognize patters.
Allowing the child to explore and handle objects in the rooms of his house (versus sitting him many hours in a crib or play pen) is not an expensive proposition.