Mental imagery or "movies in the mind" can be developed while reading books to children. Picture books have rich illustrations that help tell the story. Teaching children to see movement happening and sharing your own mental imagery will get them ready for the rich language in books that will allow them to enjoy books as much or more than movies as they move into independent reading and chapter books.

When readers don't use mental imagery in chapter books, they easily lose interest in reading. The rich language is lost on them. The pictures that help tell the story are no longer there.

Here's a great article and book to help you teach a reader to make "movies in the mind".