My readings of vision research ended years ago, with the works of Kuffler, Hubel and Wiesel about low and intermediate visual processing in the primary visual cortex. The current book I am reading, The Age of Insight, by Nobel Prize winning neurobiologist Eric Kandel, relates how artists instinctively use the physiology of this stage of vision (edge-detection, orientation and other neuron fields) to represent three-dimensional objects on two dimensional surfaces.
Chapter 17 was an eye opener for me (pun intended). Higher-stage visual processing involves connections with other cortical centers. Once again, Kandel relates the physiology of face recognition with techniques artists use to produce portraits. There are ‘face recognition patches’ in which there are cells specialized for processing faces. Some of these areas respond better to caricatured features than those more life-like. According to Kandel, the artists Kokoschka and Schiele capitalized on the brain’s ability to recognize exaggerated features of the face, by distorting features to evoke emotional responses.
In today’s watercolor experiment, I sketched two faces of opposite orientation within the same outline of a head. The head is lying on it’s side. Kandel points out that faces are much harder to recognize when presented up-side down. Apparently, there are fewer problems with horizontal orientation: in my sketch one can see each face clearly.