What Brain Science Teaches Us About Painting-PART 2

James Gurney shares how new insights in visual perception and neuroscience can help us as artists

- James Gurney

What you paint is a reflection of what you notice, and what you notice is a consequence of your conscious and unconscious visual strategies, some learned and some automatic. In the previous issue's article we looked at how images are constructed in the brain, both from the information that comes from the eyes, and from the predictive models handed down from the brain. We considered how vision is different from the camera and whether artists see differently from other people.

Now let's look at how image processing actually happens in the brain, and how we can recruit our eyes and brains to give us what we need to produce a painting.

TONE AND COLOR ARE PROCESSED SEPARATELY

According to Dr. Margaret Livingstone, the visual brain processes luminance (or tonal information) separately from color information. The two streams originate in the retina, which begins with low-level processing such as recognition of edges and contrasts. The information pathways continue to the optical cortex at the back of the brain. Although there is some crossover and interaction, the two streams-luminance and color-are largely kept separate, from the level of the retina all the way to the higher-level vision centers of the brain.

The area of the brain that interprets tone is several inches away from the area that interprets color, making the experience of tone and color distinct physiological experiences, as distinct as sight and hearing. The color stream is also called the ventral stream or the "what" stream. It is more concerned with recognizing and identifying objects. Color processing through the ventral stream is a capacity that is shared only by higher primates, not the bulk of other mammals.

The difference between these two streams may explain why classically trained artists plan their compositions by solving problems of tonal organization separately from the color arrangement.