The Neuroscience of Op Art
Artists, like neuroscientists, are masters of visual systems. Through experimentation and observation, artists have developed innovative methods for fooling the eye, enabling flat canvases to appear three-dimensional, for instance. Neuroscience—and more recently the subfield of neuroaesthetics—can help to explain the biology behind these visual tricks, many of which were first discovered by artists. “I often go to art to figure out questions to ask about science,” says Margaret Livingstone, Takeda Professor of Neurobiology at Harvard Medical School. “Artists may not study the neuroscience per se, but they’re experimentalists.”
During the 1960s, Museum of Modern Art announced this international artistic trend in 1965 in a seminal exhibition titled “The Responsive Eye.” Since then, neuroscientists have continued to probe the mechanisms by which the human eye responds to these mind-bending works.
The notion that eyes are drawn to areas of contrast is foundational to visual neuroscience. Hard-edged boundaries between light and dark attract attention and become exaggerated through visual perception. A black circle on a white background, for example, will appear darker than the same black circle on a gray background—to scientists, this phenomenon is known as “center/surround antagonism.” A similar effect occurs in Hermann’s Grid, first discovered by the physiologist Ludimar Hermann in 1870, in which “ghostlike” gray squares flicker at the intersections of black-and-white matrices.
A comparative effect results from color contrasts. Stare at a blue-and-white-striped square for a few seconds, and chances are a yellow halo will appear in your visual field. “Yet there is no yellow in this work, none at all,” the Venezuelan Op artist explained. “You see yellow because, when the blue hits the black, that is the effect on the retina. It’s an optical effect known as simultaneous contrast.”
Simultaneous contrast—the visual phenomenon behind the viral striped dress that appeared black and blue or white and gold depending on the viewer—is the principle that the perception of a color is dependent on what other colors surround it. Bright colors cast a shadow of their complementary (or opposite) color—blue contrasts yellow, red contrasts green—which is why the area surrounding the blue square takes on a golden hue.
While illusions such as these are hard-wired in the human visual system, others emerge through lived experiences. By observing the natural world, the eye learns to interpret areas of low contrast (like clouds) as a transparent overlay atop areas of higher contrast (like the sky). American painter
The appearance of motion in Op Art continues to drive research in neuroscience today. In 1957, Donald M. MacKay discovered that artists have used this mind-bending technique for centuries. One explanation for this effect lies in small, involuntary rapid-eye movements, called “microsaccades.” When presented with heavily patterned, high-contrast images, the eye (which is drawn to contrast) can’t focus its attention.
“My paintings are multifocal,” the British Op artist
While Op artists studied the science of perception, scientists have in turn looked to Op Art to ask questions about visual processes. Though their experimental techniques differ radically, their conclusions are often the same: The human visual system is not a mirror for the outside world. Rather, it is capable of seeing far beyond what is actually there.