The more I think about it, I believe the brain is primarily an image processing system....that is built on pattern recognition. Even when it's processing abstract symbols (read more from Gilberto de Paiva on this) it organizes around semantic patterns, visual patterns, logical patterns. Even emotional and behavioral patterns enable us to read and interpret a situation. Pattern recognition is what enables us to ignore or summarize most of the daily visual stimulation.
While spending 5 weeks in the trees at the Yaddo artist colony in January and February this year -- it was interesting to note the absence of signage and logos ever present in urban spaces. I got to thinking about little language, images, symbols were present even 150 years ago. Unlikely the human brain has evolved much in just a half dozen generations....so how are we managing to process everything on our laptops, shopping trips and daily commute?