I'll give you an example of how a person's understanding of media can be distorted if they are "illiterate" and their abstraction abilities have not been developed.

As an English trainer in Costa Rica, I was preparing a group of rural leaders to go to the US. All of them were excellent communicators in Spanish, many of them very intelligent, but a number of them had either no literacy or very low levels of literacy (reading and writing) in Spanish. As one of my activities, I used the image (drawing) in which there is either an old hag or a young woman, depending on how you look at the picture. This is similar to the drawings by Esher or the coup d'oeil pictures.

Both my co-instructor and I used the pictures with two different groups. What surprised us was that those students that were illiterate could not see two different images within the same picture, even if we tried to point it out to them. Whatever they saw initially was the only image they could see. On the other hand, those who were literate were able to see both when pointed out to them. I had learned about this in my teacher training, but never realized how it would impact looking at images.

Learning to read and write develops a person's ability to abstract ideas and interpret images. This would have a great impact on media as well as reading and writing. If we have new "literacies" and move away from reading and writing text, we will still need to teach the ability to abstract ideas (e.g. interpreting images, connecting symbols to information). I'm not sure our educational system is ready for that yet.