It might seem bizarre that science is using art to learn about the mind—looking for hard facts in the most ethereal of places. But great artists turn out to be the world's first neuroscientists. Consider the flightless fluffs of brown otherwise known as herring gull chicks. Since they're entirely dependent on their mothers for food, they're born with a powerful instinct. Whenever they see a bird beak, they frantically peck at it, begging for their favorite food: a regurgitated meal.
But this reflex can be manipulated. Expose the chicks to a fake beak—say, a wooden stick with a red dot that looks like the one on the end of an adult herring gull's beak—and they peck vigorously at that, too. Should the chicks see a wood stick with three red dots, they peck even faster. Abstracting and exaggerating the salient characteristics of a mother gull's beak strengthens the response. The phenomenon is known as the "peak-shift effect," since a peak pecking response comes from a shifted stimulus. In it lies one of the core principles of visual art.
In 1906, Pablo Picasso was determined to reinvent the portrait and push the boundaries of realism, and one of his early subjects was Gertrude Stein. After months in his Paris studio, carefully reworking the paint on the canvas, Picasso still wasn't satisfied. He didn't finish the painting until after a trip to Spain.
What Picasso saw there that affected him so deeply has been debated—the ancient Iberian art, the weathered faces of Spanish peasants—but his style changed forever. When he returned to Paris, he gave Stein the head of a primitive mask. The perspective was flattened and her face became a series of dramatic angles. Picasso had intentionally misrepresented various aspects of her appearance, turning the portrait into an early work of cubist caricature.
Despite the artistic license, the painting is still recognizable as Stein. Picasso took her most distinctive features—those heavy, lidded eyes and long, aquiline nose—and exaggerated them. Through careful distortion, he found a way to intensify reality. As Picasso put it, "Art is the lie that reveals the truth."
What's surprising is that such distortions often make it easier for us to decipher what we're looking at, particularly when they're executed by a master. Studies show we're able to recognize visual parodies of people—like a cartoon portrait of Richard Nixon—faster than an actual photograph. The fusiform gyrus, an area of the brain involved in facial recognition, responds more eagerly to caricatures than to real faces, since the cartoons emphasize the very features that we use to distinguish one face from another. In other words, the abstractions are like a peak-shift effect, turning the work of art or the political cartoon into a "super-stimulus."
At first glance, the premise of neuroaesthetics seems bizarre: Scientists are using artists to learn about the mind. They're looking for objective facts in the most subjective of places, using paintings and sculptures as sources of experimental data. Sometimes, it seems as if the scientists are simply trying to catch up with insights long ago "discovered" by artists.
observes Semir Zeki, a neurobiologist at University College London and director of the Institute of Neuroesthetics. Picasso had an intuitive understanding of the mechanics of vision—which he expressed in his paintings. Likewise, the power of a Rembrandt self-portrait is not an accident: The Old Masters knew how to captivate the eye and the mind, which is why we still gaze at their canvases in museums. Scientists can learn about the mind by reverse-engineering art.
The artist is, in a sense, a neuroscientist, exploring the potentials and capacities of the brain, though with different tools,
Artists have learned to exploit other features of the visual system, too. The brain is an evolved machine, subject to all sorts of biological constraints. All of our color perception, for example, is wrangled from the responses of three different photoreceptors in the eye. Great art manages to translate these "limitations" into riveting creations.
When Mark Rothko painted an entire canvas in three shades of maroon, or Josef Albers painted his intensely colorful Homage to the Square in five slightly different shades of yellow, these abstract artists were tickling the parts of our visual cortex concerned with the processing of color. The visual cortex excels at perceiving contrasts between different colors, such as blue and yellow, but these paintings deliberately avoided sharp contrasts of color. The result is that the subtly distinct shades seem to shimmer and shift before our very eyes. We are riveted by these stimuli we can't understand.
The strategy of taking advantage of the brain's imperfections isn't confined to modern art. Consider Leonardo da Vinci's portrait of the Mona Lisa, perhaps the most famous painting in the world. The smile is notoriously enigmatic, a precise summary of an ambiguous emotion. But what is it about those slyly upturned lips that make the portrait so intriguing?
Margaret Livingstone, a neuroscientist at Harvard and author of Vision and Art, argues that da Vinci exploits the peculiar structure of the retina. The facial expression of the Mona Lisa fluctuates depending on which part of our retina we are using to look at her mouth, she explains. When we first look at the painting, our eyes are automatically drawn to her eyes, which means our peripheral vision perceives her smile. This part of the retina naturally focuses on the shadows cast by her cheekbones, which serve to exaggerate the curvature of her lips. As a result, our peripheral vision concludes that the Mona Lisa is smiling. Livingstone demonstrated this by blurring the entire painting with Adobe Photoshop to replicate what we would see if we were relying solely on peripheral vision. The end result: a much happier Mona Lisa.
But when we focus on her mouth, the retina ignores the shadows—the blurriness disappears. Instead, we fixate on the lips of the Mona Lisa, which are virtually expressionless. All of a sudden, she is no longer happy: The painting has literally changed before our eyes. This ambiguity is intriguing, Livingstone argues, as we keep staring at the painting to figure out what she's actually feeling. "I do not mean to take away the mystery of Leonardo," Livingstone told the New York Times. "It took the rest of us 500 years to figure out what he was up to."
PEAK SHIFT: We find deliberate distortions of a stimulus even more exciting than the stimulus itself—which is why cartoon caricatures grab our attention.
GROUPING: It feels nice when the distinct parts of a picture can be grouped into a pattern or form. The brain likes to find the signal amid the noise.
BALANCE: Successful art makes use of its entire representational space, and spreads its information across the entire canvas.
CONTRAST: Because of how the visual cortex works, it's particularly pleasing for the brain to gaze at images rich in contrast, like thick black outlines or sharp angles—or, as in the geometric art of Mondrian, both at once.
ISOLATION: Sometimes less is more. By reducing reality to its most essential features—think a Matisse that's all bright color and sharp silhouettes—artists amplify the sensory signals we normally have to search for.
PERCEPTUAL PROBLEM SOLVING: Just as we love solving crossword puzzles, we love to "solve" abstract paintings such as cubist still lifes or Cézanne landscapes.
SYMMETRY: Symmetrical things, from human faces to Roman arches, are more attractive than asymmetrical ones.
REPETITION, RHYTHM, ORDERLINESS: Beauty is inseparable from the appearance of order. Consider the garden paintings of Monet. Pictures filled with patterns, be it subtle color repetitions or formal rhythms, appear more elegant and composed.
GENERIC PERSPECTIVE: We prefer things that can be observed from multiple viewpoints, such as still lifes and pastoral landscapes, to the fragmentary perspective of a single person. They contain more information, making it easier for the brain to deduce what's going on.
METAPHOR: Metaphor encourages us to see the world in a new way: Two unrelated objects are directly compared, giving birth to a new idea. Picasso did this all the time—he portrayed the bombing of Guernica, for example, with the imagery of a bull, a horse, and a lightbulb.