Why make a cynical assumption at all? Francis R. Willett, Donald T. Avansino, Leigh R. Hochberg, Jaimie M. Henderson, and Krishna V. Shenoy are real people. You could, you know, just ask them.
What cynical assumption? It is well known visual cortex can't do too many things at the same time. The famous gorilla experiment shows this. And if you need to imagine anything graphical it most likely involves visual cortex.