Television, in my opinion, suppresses imagery by eliminating the need to image.
Later, an increasing variety of books can be included. The story line of these books with their descriptions of characters, places and events will exercise imagery of children like nothing else. This is where Television and Movies cheat the child. At a time when children need to be exercising their imagery, someone else through technology is handing it to them on a silver platter. TV and Movies today "let it all hang out!" They leave nothing to the imagination.
As the children watch TV, as they often do for more hours than their father works, it does nothing for the development of their neurological infra-structure of imaging, with one exception perhaps.
It may leave them with some eidetic images that are quickly created because of their emotional impact--like the frightening flashbacks of war veterans. Our kids can do without this, I’m sure!