The origins of autism are thought to lie in early brain development. During the first three years of life, the brain grows at a tremendous rate. In autistic children neurons seem to connect haphazardly, causing widespread abnormalities, especially in the cerebellum, which integrates thinking and movement, and in the limbic region, which integrates experience with specific emotions. Abnormalities in these regions seem to stunt interest in one’s environment and in social interaction. Autistic children have narrowed fields of attention and a poor ability to recognize faces. They are more likely to view a face, for example, as individual components rather than as a whole. Imaging studies have shown that when autistic children see a familiar face, their pattern of brain activation is different from that of normal children.
That narrowed focus may explain the autistic child’s ability to concentrate endlessly on a single repetitive activity, such as rocking in a chair or watching clothes tumble in a dryer. Only one out of 10 autistic children shows special skills.
In a 1999 paper, Snyder and his colleague John Mitchell challenged the compulsive-learning explanation for savant abilities, arguing that the same skills are biologically latent in all of us. “Everyone in the world was skeptical,” says V. S. Ramachandran, director of the Center for Brain and Cognition at the University of California at San Diego. “Snyder deserves credit for making it clear that savant abilities might be extremely important for understanding aspects of human nature and creativity.”
Snyder’s office at the University of Sydney is in a Gothic building complete with pointed towers and notched battlements. Inside, Nadia’s drawings of horses adorn the walls; artwork by other savants hangs in nearby rooms.
Snyder’s interest in autism evolved from his studies of light and vision. Trained as a physicist, he spent several years studying fiber optics. At one time he was interested in studying the natural fiber optics in insects’ eyes. The question that carried him from vision research to autism had to do with what happens after light hits the human retina: How are the incoming signals transformed into data that are ultimately processed as images in the brain? Snyder was fascinated by the processing power required to accomplish such a feat.
During a sabbatical at the University of Cambridge in 1987, Snyder devoured Ramachandran’s careful studies of perception and optical illusions. One showed how the brain derives an object’s three-dimensional shape: Falling light creates a shadow pattern on the object, and by interpreting the shading, the brain grasps the object’s shape. “You’re not aware how your mind comes to those conclusions,” Snyder says. “When you look at a ball, you don’t know why you see it as a ball and not a circle. The reason is your brain is extracting the shape from the subtle shading around the ball’s surface.” Every brain possesses that innate ability, yet only artists can do it backward, using shading to portray volume.
“Then,” Snyder says, speaking slowly for emphasis, “I asked the question that put me on a 10-year quest.” How can we bypass the mind’s conceptual thinking and gain conscious access to the raw, uninterpreted information of our basic perceptions? Can we shed the assumptions built into our visual processing system?
A few years later, he read about Nadia and other savant artists in Oliver Sacks’s The Man Who Mistook His Wife for a Hat and Other Clinical Tales. As he sat in his Sydney apartment one afternoon with the book in hand, an idea surfaced. Perhaps someone like Nadia who lacked the ability to organize sensory input into concepts might provide a window into the fundamental features of perception.
Snyder’s theory began with art, but he came to believe that all savant skills, whether in music, calculation, or spatial relationships, derive from a lightning-fast processor in the brain that divides things—time, space, or an object—into equal parts. Dividing time might allow a savant child to know the exact time when he’s awakened, and it might help Eric find the sweet spot in a room by allowing him to sense millisecond differences in the sounds hitting his ears. Dividing space might allow Nadia to place a disembodied hoof and mane on a page precisely where they belong. It might also allow savant twins to instantaneously count matches spilled on the floor (one said “111”; the other said “37, 37, 37”). Meanwhile, splitting numbers might allow math savants to factor 10-digit numbers or easily identify large prime numbers, which are impossible to split.
Compulsive practice might enhance these skills over time, but Snyder contends that practice alone cannot explain the phenomenon. As evidence, he cites rare cases of sudden-onset savantism. Orlando Serrell, for example, was hit on the head by a baseball at the age of 10. A few months later he began recalling an endless barrage of license-plate numbers, song lyrics, and weather reports.
If someone can become an instant savant, Snyder thought, doesn’t that suggest we all have the potential locked away in our brains? “Snyder’s ideas sound very New Age. This is why people are skeptical,” Ramachandran says. “But I have a more open mind than many of my colleagues simply because I’ve seen [sudden-onset cases] happen.”
Bruce Miller, a neurologist at the University of California at San Francisco, has seen similar transformations in patients with frontotemporal dementia, a degenerative brain disease that strikes people in their fifties and sixties. Some of these patients, he says, spontaneously develop both interest and skill in art and music. Brain-imaging studies have shown that most patients with frontotemporal dementia who develop skills have abnormally low blood flow or low metabolic activity in their left temporal lobe. Because language ability is concentrated in the left side of the brain, these people gradually lose the ability to speak, read, and write. They also lose face recognition. Meanwhile, the right side of the brain, which supports visual and spatial processing, is better preserved.
“They really do lose the linguistic meaning of things,” says Miller, who believes Snyder’s ideas about latent abilities complement his own observations about frontotemporal dementia. “There’s a loss of higher-order processing that goes on in the anterior temporal lobe.” In particular, frontotemporal dementia damages the ventral stream, a brain region that is associated with naming objects. Patients with damage in this area can’t name what they’re looking at, but they can often paint it beautifully.
Miller has also seen physiological similarities in the brains of autistic savants and patients with frontotemporal dementia. When he performed brain-imaging studies on an autistic savant artist who started drawing horses at 18 months, he saw abnormalities similar to those of artists with frontotemporal dementia: decreased blood flow and slowed neuronal firing in the left temporal lobe.