Neuroscientists have confirmed what any kid knows: Third grade changes everything. Compared to kids just out of second grade, recent third-grade graduates use their brains in an entirely different way when solving math problems, a study in an upcomingNeuroImage finds.
“I think this is really fascinating,” says cognitive neuroscientist Daniel Ansari of the University of Western Ontario in London, Canada. “Anybody who doesn’t believe that development is important needs to read this paper, because it really shows how dynamically the brain changes as we learn.”
Cognitive neuroscientist Vinod Menon of the Stanford University School of Medicine and his colleagues recruited 90 children, aged 7 to 9, who had just completed either second or third grade.
The youngsters calculated easy (3 + 1 = 4) or more complex (8 + 5 = 13) addition problems while Menon and his team scanned the children’s brains using functional MRI.
Third-graders’ brains behaved very differently than second-graders’, the team found. “It’s not a minor change,” Menon says. “At this point, what’s clear is that the brain and brain function is undergoing major changes.”
Overall, second-graders’ brains tackled the easy and hard problems about the same way. Third-graders’ brains responded very differently to the easy and the hard questions. This may reflect a cognitive strategy shift as third-graders grow more adept at handling the easy problems.
Third-graders showed heightened activity in a brain region important for working memory, which keeps relevant info handy. Earlier studies of older children found that this region, the left dorsolateral prefrontal cortex, was less active with age while doing math, so the new results may reflect an age-specific approach to math that later gives way to something else, the authors suggest.
It is important to understand the development of the brain when considering how we teach kids in different grades.