This is a representation of the brain as a city, where each area corresponds to a specific functional zone of cerebral cortex. It was made all with Bic pens.
Moreover, left and right side are drawn with both hands, respecting the specific characteristics of the corresponding cerebral hemispheres. So the black part is drawn with the right hand and corresponds to the left cerebral hemisphere: no proportions, no perspective, a lot of visual detail, rational part home of the ego. The red one is drawn with the left hand (right hemisphere): 3D representation, synthetic, dreaming and creative side.
The reason for the left part doesn’t contain a detailed series of scientific terms, but only some words indicating generic features, is just because only the left hemisphere (right hand) is the analytic one.
More information here: http://www.be.net/gallery/The-Self-drawing-Brain/923519