Dual coding

"The dual coding theory, a theory of cognition, was first advanced by Allan Paivio of the University of Western Ontario. The theory postulates that the human cognition consists of two subsystems that process knowledge simultaneously, one processing the verbal objects and one dealing with visual objects. The two systems have different functions; the verbal subsystem processes and stores linguistic information whereas the visual subsystem processes and stores images and pictorial information. While the two subsystems can be activated independently, the interrelations and connections of the two systems allow the dual coding of information."

Source:
http://www.dualcode.com/about/dualcodingtheory.htm