ARTICLE IN BRIEF
The death of Kim Peek, the man who inspired the character with savant syndrome in the 1988 movie, “Rain Man,” elicits discussion about advances in the understanding of the condition.
In the 1988 movie, “Rain Man,” Charlie Babbitt, a slick operator and user of people, tells his autistic brother Raymond he will see him again in two weeks. “How many days is that Raymond?”
“Fourteen days,” Raymond says. “336 hours. Course that's 20,166 minutes. 1,290,600 seconds.”
It is the kind of spectacular feat—like instantly calculating the number of toothpicks that have fallen on the floor, or counting cards in a Las Vegas gambling casino—that was made for the movies. However, Raymond Babbitt was not a fabrication of Hollywood scriptwriters, but was inspired by Kim Peek, who died of a heart attack at the age of 58 on Dec. 19, 2009.
Peek was a human rarity. Born with macrocephaly and congenital brain abnormalities, he was not autistic but had social and other disabilities as a result of those abnormalities that were similar to autism. But to say that he “suffered” from his condition is to misread the extraordinary implications of the special variant of autism—known as savant syndrome (the term has replaced the archaic “idiot savant”)—that was his condition in life.
The story of Kim Peek, and of savant syndrome generally, is a story of the brain's extraordinary neuroplasticity, and the ways in which that plasticity allows for humans to compensate for their disabilities with wondrous and spectacular abilities. From an early age, Peek had a prodigious memory and as an adult he was able to read and memorize whole books, as well as vast amounts of information about far-flung topics. And like many savants, he possessed an extraordinary “calendar memory”—the ability to match days with dates many years past. With his father, he travelled widely and spoke about his condition in the wake of the notoriety that came with “Rain Main.”
NEW UNDERSTANDING: SAVANT SYNDROME
Of special interest to neurologists today is a variant of savant syndrome, acquired savant syndrome, in which individuals develop remarkable artistic or creative talents after suffering a debilitating brain trauma.
“More has happened to understand savant syndrome in the 20 years since ‘Rain Man’ than in the 120 years since it was first described in 1887 by Dr. J. Langdon Down,” psychiatrist Darold Treffert, MD, told Neurology Today.
Dr. Treffert has become a leading expert on savant syndrome since he started a Children's Unit at a psychiatric hospital in Wisconsin following his residency. There he encountered such oddities as an autistic child who had memorized the entire Milwaukee bus system and another child who was totally mute, but could put together a 250-piece jigsaw puzzle in minutes.
According to a Web site maintained by Dr. Treffert — www.savantsyndrome.com —approximately one in 10 people with autistic disorder have some savant skills. In other forms of development disability, mental retardation or brain injury, savant skills occur in less than 1 percent of these people. These other forms are more common than autistic disorder; however, approximately 50 percent of those with savant syndrome have autistic disorder, and the other 50 percent have some other form of developmental disability, mental retardation or brain injury or disease. Not all savants are autistic, and not all autistic persons are savants.
Dr. Treffert explained that there is a notable uniformity about savants and that the unique skills they display are almost always in five general areas: art, music, calendar counting, mechanical ability, and “lightning calculation.”
“Those tend to be right brain skills,” Dr. Treffert said. “Most savants are very deficient in language which is a left hemisphere skill but are very prolific in right brain skills.”
This strongly suggests to Dr. Treffert and others who have studied the condition is that savant syndrome is a phenomenon of left brain damage and right brain recruitment or compensation. The other ubiquitous clinical observation about savants that is neurologically suggestive is their prodigious memory— called “memory without reckoning,” meaning that they typically possess a mechanical ability to reproduce their memories but without any meaning or content.
“This is because there is injury to the higher cortico-limbic circuit for semantic or cognitive memory and compensation by the lower level cortico-striatal circuit for the more primitive habit memory,” Dr. Treffert suggested.
ACQUIRED SAVANT SYNDROME
Complementing this is the phenomenon of acquired savant syndrome, which has emerged very recently as an area of research interest. Neurologist L. Bruce Miller, MD, clinical director of the Memory and Aging Center at the University of California-San Francisco, has documented cases of patients with damage to the frontal cortex, resulting in progressive aphasia and degeneration of language capacities, who have developed striking visual creative abilities.
“In the setting of severe language deficiencies these patients sometimes become prolific and wonderful painters, often with little or no training,” Dr. Miller told Neurology Today. “These patients do not have Alzheimer disease; they have a disorder that affects the front part of the brain, but that spares the posterior section of the brain involved with visual perception.”
Experts believe that savant syndrome is a phenomenon of left brain damage and right brain recruitment or compensation.
In a 2008 article in Brain, Dr. Miller and colleagues described a patient with progressive aphasia who developed an intense desire to produce visual art. The patient was especially fascinated with the French composer Maurice Ravel, and strove to render Ravel's masterpiece, “Bolero,” into a visual form.
“Later paintings, achieved when [the patient] was nearly mute, moved towards increasing photographic realism, perhaps because visual representations came to dominate [her] mental landscape during this phase of her illness,” the authors stated. “Neuroimaging analyses revealed that, despite severe degeneration of left inferior frontal-insular, temporal and striatal regions, [the patient] showed increased grey matter volume and hyperperfusion in right posterior neocortical areas implicated in heteromodal and polysensory integration.”
Dr. Miller said the artistic abilities of acquired savantism do not bloom suddenly, but emerge slowly as a consequence of the brain's nearly obsessive need to compensate for its disability. “For someone who has never trained as an artist to become visually fluent, they have to practice,” he said. “But they often become very obsessed, painting or drawing the same picture over and over again until it becomes perfected.”
And yet, in the case of the acquired condition, there is also a shadow that hovers in the background of the creativity. “Eventually, the degeneration overwhelms the compensatory capacities,” Dr. Miller said. “It's sad because it seems the creativity is heralding the onset of degeneration.”
As much as has been learned in the past two decades about savant syndrome, it remains a wonder about which much is still speculative. For instance, one of the most baffling phenomena common to congenital savants is that of calendar counting—a skill that would seem to have no functional utility.
Dr. Treffert believes that it may be a remnant of “genetic memory,” retrieved by the savant from a time when for humankind the calendar was a matter of survival. If true, it confirms that the human brain does not come into the world waiting to be wired.
Savants seem to know things they never learned, Dr. Treffert noted. “We didn't start with a blank disc, but with all kinds of stuff installed,” he said.
For clinicians treating patients of all kinds with neurological disabilities or trauma, the phenomenon of savant syndrome underscores the importance of playing to a patient's strengths—what Dr. Treffert calls “training the talent.”
Dr. Miller agrees. “It's taught me to think about patients' strengths as well as their weaknesses,” he said. “Neurologically, its all about what system in the brain is degenerating and which system is compensating.”