Adding up

Why is it that some students find math easy, while others struggle with it throughout their school years? And what explains those rare students, one in 10,000 or fewer, who can master advanced mathematics at an early age and with little training?

These are age-old questions, and attempts to answer them in terms of pure and simple biology are just as unsatisfying as explanations in terms of the environment alone, say many researchers.

But a new study suggests that, whatever their ultimate cause, differences in brain activity between mathematically gifted and nongifted students do exist, even at a relatively young age. The study, published in Neuropsychology (Vol. 18, No. 2), was authored by cognitive psychologists Harnam Singh, PhD, a researcher at the U.S. Army Research Institute for the Behavioral and Social Sciences in Fort Benning, Ga., and Michael O'Boyle, PhD, a psychology professor at the University of Melbourne.

Singh and O'Boyle used functional magnetic resonance imaging to measure the brain activity of 36 adolescents of either high mathematical ability--as identified through a gifted and talented program at Iowa State University--or average ability. They focused on 13- and 14-year-old students, rather than older teenagers or adults, to reduce the effect of training as much as possible, says O'Boyle.

The researchers' results indicate that mathematically gifted students are unusually adept at coordinating the activity of the two cerebral hemispheres, which may make it easier for them to learn complex mathematics. Such students found it easier to combine information from the left and right visual fields than nongifted students, and they also engaged the two halves of the brain more equally, including areas associated with attention and planning.

The experimental task itself was not numbers-focused. Instead, students were asked to compare letters presented to the right and left visual fields using either local or global criteria. The ability to carry out this kind of spatial comparison is correlated with mathematical giftedness, says O'Boyle.

"For a hundred years, psychometrics have done a great job of identifying high ability in many domains, but we haven't spent as much time identifying underlying mechanisms responsible for why people test this way," says O'Boyle. "I think we've gone one step further."

Limitations

The study's findings are provocative but not conclusive, say researchers on brain lateralization, giftedness and mathematics education.

For one thing, it is not clear that mathematically gifted adolescents are the only ones who have enhanced interhemispheric interaction, says Michael Peters, PhD, a neuropsychologist at the University of Guelph in Canada. If the study had included a control group gifted in some other domain, such as music or language, it could have provided stronger evidence for that claim, Peters says. Furthermore, participants in the study only performed one sort of task, so generalizing to interhemispheric interaction in general is a big leap, says Robert J. Sternberg, PhD, APA past-president and head of Yale University's Center for the Psychology of Abilities, Competencies and Expertise.

Finally, the study only identifies a correlation--not a causal relationship--between mathematical giftedness and interhemispheric coordination, notes Art Baroody, PhD, an educational psychologist at the University of Illinois at Urbana-Champaign. Some research has found that mathematically gifted children are more likely to suffer from myopia, but that doesn't mean that poor eyesight is a cause of mathematical talent, he says.

O'Boyle notes that the study wasn't designed to answer questions about the ultimate cause of the difference between mathematically gifted and nongifted students.

"We don't know whether their brain organization is a byproduct of their biology or whether it's the product of some learning opportunity they've been exposed to," says O'Boyle.

Applications

Researchers agree that practical applications of this kind of research, even if corroborated by other studies, are a long way off. But O'Boyle speculates that brain imaging might eventually be used, together with more traditional tests, to tailor teaching strategies to individual students.

"We may be able to use images of people's brains, just like we use psychometric tests, to identify the capacity for learning certain types of skills," says O'Boyle.

At this point, however, research on giftedness and the brain is still in its infancy, and any application to real-world education would be premature, cautions Camilla Benbow, EdD, a professor of psychology at Vanderbilt University engaged in a long-term study of mathematically gifted youth.

And not everyone agrees that brain imaging would add much to the kinds of psychometric and behavioral tests that already exist.

"All that matters is if a kid wants to do the work and can do the work," says Ellen Winner, PhD, a psychologist at Boston College who is studying biological correlates of musical giftedness. "I don't think we need these subtle measures of brain activity. It's a lot easier to do behaviorally."

Nonetheless, even if such research doesn't help target specific kinds of teaching to individual children, it could help researchers understand the process of math learning in general--not just for gifted children, but also for children of average ability, says O'Boyle.

"Right now these findings are at such an early stage of development, the applications are hard to see," says Benbow, who has collaborated with O'Boyle in the past. "But we're hoping down the line that this type of knowledge will help us create better educational approaches for teaching these kids."