What's a "thinking cap" -- and could it make me a genius?

­Snyder's work is predicated on the idea that all humans have the ability to produce works of both creative and scientific genius. Our ability to do so is ironically "impaired" by normal brain functioning. The researcher, who directs the Centre for the Mind in Sydney, Australia, is primarily involved with studying autistic savants, people who are mentally deficient in some areas but excel in other, more specialized areas, like mathematics or music. Snyder theorizes that we're all potential savants, and this idea is supported by cases of people who've suffered brain damage but gain an extraordinary ability. Upon investigation, he found these people had all suffered damage to the left side of their brains [source: Phillips]. To test his theories, Snyder turned to transcranial magnetic stimulation, the "thinking cap."

Brain function remains largely a mystery to science, but neurologists have come to believe the right hemisphere is concerned with evaluating the big picture, or "the forest," while the detail-oriented left hemisphere evaluates "the trees" [source: Brown]. This division of responsibilities is called the lateralization of brain function. Snyder hypothesizes that those with properly functioning left brain hemispheres possess the ability to create what he calls mindsets -- personal, mental definitions based on experience [source: Phillips]. These mindsets are created through our interaction with the world. When we encounter a new experience, like seeing an animal for the first time, the brain categorizes and stores our perception of that animal. Is it dangerous? Does it have fur? All of this is packaged and available for recall so we don't have to relearn our initial perception of the animal each time we encounter it [source: Phillips].

Snyder believes that the savant traits he's trying to replicate in people with normal brain functions results from a loss of the ability to create mindsets. Therefore, each experience is fresh and untainted by past encounters. This "raw data" would allow a savant -- and apparently a person under TMS -- to produce a drawing or edit text unencumbered by any previous notions about the subject.

It's impossible to say whether Snyder's hypothesis is correct. Although his tests using TMS support his theories, science doesn't have a firm enough grasp on the human brain to prove or disprove them. It wasn't until the late 1990s that neurologists came to accept the lateral divisions of brain function concept [source: Brown].

­Snyder's theories are supported by demonstrated effects for another use for TMS -- treating mental illness by disrupting brain function. Although it has emerged in Israel and Canada as an alternative to electroconvulsive therapy (ECT -- more commonly known as shock therapy), it has yet to receive FDA approval for widespread use in the United States [source: NAMI]. It's been widely shown that TMS can be used to treat conditions like schizophrenia; the effectiveness of TMS in treating mental illness, coupled with Snyder's results, show what could be a blurring of the line between insanity and creative genius.

­Medicine has suspected a link between madness and creativity for centuries. Artist Vincent Van Gogh provided ample anecdotal evidence when he lopped off the lower lobe of his left ear in 1888 and gift wrapped it for a prostitute he loved. Author Ernest Hemingway, long plagued by depression, may have done the same when he took his own life with a shotgun in 1961. These cases provide insight into the dynamic relationship between mental illness and creativity, but no rational explanation.

The explanation may lie in a condition shared by highly creative people and those with hallucinatory mental illnesses like schizophrenia -- low latent inhibition (LI). Each of us is constantly assaulted with sensory information; that raw data which Snyder believes autistic savant have trouble converting into mindsets. Humans and other primates have evolved enough to weed through this information and consider only what we need to survive, to perform a necessary task or to consider data we haven't already catalogued. The other information is unconsciously discarded, filtered through the process of latent inhibition. It's why we tend not to latch onto the constant buzzing of fluorescent lights overhead or compile snippets of conversations in crowded restaurants into a senseless whole.

A low level of latent inhibition has been shown in schizophrenics [source: Weickert, et al]. Because they can't distinguish between external and internal stimuli (for example, voices), schizophrenics attach meaning to the sensory input people with normal latent inhibition unconsciously ignore [source: Carson].

Harvard psychologist Dr. Shelley Carson found that highly creative people also experience a lower LI threshold. What creative people do with the additional stimuli appears to be the separation between creativity and insanity. In a 2004 study, Carson found that test subjects with low latent inhibition coupled with a relatively high IQ (120 to 130) also had creative abilities. Carson postulated that people with high intellects aren't assaulted by the additional information allowed into their consciousnesses through low LI like schizophrenics are. Instead, they make creative use of it: "Intelligence allows you to manipulate the additional stimuli in novel ways without being overwhelmed by them" [source: Carson].

The implication of this is, of course, that schizophrenics simply have lower intellects than highly creative people. Each group teeters on opposite sides of the same raging river of information and stimuli, holding ground only through their respective intelligence levels. While this may be an obvious conclusion, the exception that disproves the rule (schizophrenics who maintain a high intellect) doesn't support it. Studies have found a decline in intellect among some schizophrenics; but others show no decline -- remaining either at the same high or low intelligence quotient they possessed prior to developing the mental disorder (which appears on average at age 16 for males and 20 for females) [source: Weickert, et al, Carson].

­If it isn't intellect that separates genius from insanity in the human brain, then what does? Science simply doesn't know yet; what constitutes that blurry line remains a mystery. Perhaps it will be Snyder's forays into the skulls of his test participants using the thinking cap that will finally force the brain to give up its secrets.