Monday, April 15, 2013

Searching for Genius in the Brain

Genius is a big concept to get one’s head around. I was surprised to find that no studies of this topic have ever been reported in the scientific literature. There exist numerous studies of intelligence, creativity, personality—some of the key ingredients—but none regarding the “big one.” Perhaps that is why such a diverse array of panelists were brought together to discuss genius at the World Science Festival’s Beautiful Minds: The Enigma of Genius—a physicist expert in string theory, a director, a mathematician, a psychologist, a neuroscientist, a neuropsychologist, and a composer. I know that one panelist is not a genius (myself), and suspect that at least two are (Julie TaymorPhilip Glass). If we were to design a study of genius, how would we go about it?
Measures of intelligence have been around since the turn of the last century, with the introduction of Alfred Binet’s test, in 1905, to help identify students who needed extra help in school. These tests have grown to be highly refined over the 20th century, with current measures being some of the most reliable and valid measures of human behavior in existence. If genius were merely the measurement of high intelligence, we could easily identify such individuals by their membership in societies such as Mensa (98th percentile), Glia (99.9th percentile), or Mega (99.9999999th percentile). Something like this happened with a researcher named Lewis Terman, who used IQ tests to select the brightest students (their average IQ was 151), and followed their life progress over time. These students did extraordinarily well, achieving great success in science and industry (2000 scientific publications and 70 “American Men of Science”). However, one man tested by Terman had an IQ that was too low to qualify for the study: Nobel Prize winner for physics William Shockley, co-inventor of the transistor and certifiable genius. Oh.
So, unusually high creative capacity is another distinguishing characteristic important to genius. But it is nearly impossible to get access to folks like Julie Taymor or Phillip Glass (on the one hand) and, having pulled them into an MRI scanner, tell them to “create!” Rather, our field tries to break this big thing (creativity) down into parts that are reliably measured in the laboratory. One such measure, relied upon too heavily over the last 50 years, is of so-called “divergent thinking,” which asks people to think of as many different/creative ways they can to use a common object such as a brick. Research subjects give answers ranging from “to throw through a window” (less creative) to “cufflinks for the jolly green giant” (more creative). They also are asked to draw as many figures using four lines (straight line, curvy line, dot, all count as 1 line) as possible in a certain amount of time. These measures of verbal and non-verbal divergent thinking are commonly scored in terms of “fluency” (number of items produced), “flexibility” (number of different categories produced), and “originality” (the unusual or low frequency of the response). There are similar methods to measure insight (Remote Associates Test), flow, convergent thinking, persistence, openness to experience, and other pieces of the big puzzle of creativity. We link all of these measures to what we see in terms of brain structure and function to make inferences about creativity writ large.
But what does this look like in the brain? During the panel discussion, I brought up the notion of “transient hypofrontality” on several occasions. This is not just some neuroscience jargon, but represents my best attempt at a model for how one aspect of creativity (divergent thinking) works in the brain. I must give credit to Arne Dietrich, a big thinker in the creativity field, who coined the term and with whom I have had several discussions about the subject. What we found in our research was surprising: in individuals with higher divergent thinking ability, lower measures of brain integrity were also found (whether measured by biochemistry, white matter fidelity, or cortical thickness), particularly within the frontal lobes (at its most basic, the part of the brain that inhibits us from doing things we should not do, and organizes our behavior). We believe that this “disinhibitory” capacity of lower organization, in our normal young cohort, allows them to spin out more (think fluency) and unusual (think originality) ideas during divergent thinking tests. To use a poor metaphor, they have their foot off the brakes and more on the accelerator when performing these tests of divergent thinking by virtue of their frontal lobe organization. Now, they will need their frontal lobes later to push their unusual ideas forward to an unforgiving world, so the “transient” is important in “hypofrontality.”
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