As the mama of a toddler, I'm a first-rate color spotter. "Look!" I say enthusiastically. "Could you get the yellow cup?" Or the blue block, the red crayon, the green shirt, or, oh, sorry kitty, the gray-and-white cat.
Yet, until reading Michael Marmor's homage to color perception and art in the latest issue of Stanford Medicine magazine, I hadn't once harkened back to my biology-major days of rods and cones and color perception. Marmor, MD, is an ophthalmologist who has studied art history through the lens (sorry, couldn't be helped) of visual perception.
A quick primer: Our ability to detect motion, light-dark boundaries and forms evolved way before we could discern colors. To identify colors, we rely on three types of cells called cones: Each cell can pick out red, blue or green light. These messages about color come to the brain in the form of comparisons. Marmor explains:
Although colors are analyzed by blue-yellow and red-green comparisons, the basic circuitry that identifies edges, form, motion and depth responds only to changes in brightness. These discriminations are colorblind, and the sensation of color is superimposed later in the brain upon a 'black and white' image of the world.
Take the painting "Uprooted Tree" above by Ernst Ludwig Kirchner. Our eyes struggle to pick out the dead branches from the live branches and the rocks because they are all of a similar brightness, Marmor says.
There are plenty of additional optical revelations in the piece itself: I urge you to take a look.
Previously: What art and the humanities bring to medicine: a look from Stanford Medicine magazine and Discover Magazine looks at super human vision
Painting by Ernst Ludwig Kirchner courtesy of Hajotthu and the Sprengel Museum