MRIs show different brain activity patterns for kids with math learning disabilities
When kids with math learning disabilities solve a math problem with number symbols, they approach and process it differently than typical kids. But differences disappear when numbers are shown as dots.
Matt Chinworth
Some kids struggle with math. Now, scientists have pinpointed some of the specific thinking processes and brain regions that might explain why math is a little harder for some than others.
When given simple math problems, kids with math learning disabilities in a new study were less cautious about giving their answers and did not slow down after making errors compared with kids with typical math skills. But these differences disappeared when those same kids were given problems with dots to represent numbers instead of Arabic number symbols, researchers report February 9 in the Journal of Neuroscience.
The idea that number symbols can be a challenge is not new. “There’s a very consistent observation that it’s the symbolic processing that is really the struggle for children with difficulties,” says Bert De Smedt, an educational neuroscientist at KU Leuven in Belgium who was not involved in the study. But the subtle differences in how kids with math learning disabilities approach problems, like not answering cautiously and not slowing down after errors, advance understanding of what underlies their difficulties with number symbols, he says.
In the new study, researchers tested second- and third-grade kids with and without math learning disabilities by showing them two numbers from 1 to 9 and giving the kids a few seconds to pick which number they thought was larger. The researchers recorded how long it took kids to answer questions and observed kids’ brain activities using an MRI scanner. The team analyzed the data about the kids’ performance and behavior during the test using a complex mathematical analysis designed to find subtle patterns in behavior, like how carefully children answered throughout the experiment and how they changed their behavior after mistakes. They then compared those behavior patterns with brain activity.
“We weren’t necessarily interested in the performance of this task but how they may approach this task differently between the two groups of children,” says Hyesang Chang, a cognitive neuroscientist at San José State University in California, who did the research while at Stanford University.
From the MRI data, Chang and colleagues found that the lack of caution in kids with math learning disabilities when giving answers was associated with lower activity in the middle frontal gyrus, a brain region associated with processing numbers as well as focus, impulse control and adapting to changing circumstances. Meanwhile, not slowing down after errors was associated with lower activity in the anterior cingulate cortex, a brain region involved in detecting errors and monitoring performance.
When kids were given similar problems with dots instead of numbers, those differences went away. Children with math learning disabilities had the same amount of activity in the two identified brain areas as kids without those disabilities. Chang notes, however, that the analysis is exploratory and cannot show cause and effect between brain activity in these regions and the math abilities of these children.
Identifying these brain regions suggests that explaining differences in math skills is more complex than finding one part of the brain that handles math and numbers. Instead, the study suggests that brain areas that process information and find errors seem to be key, says Marie Arsalidou, a developmental cognitive neuroscientist at York University in Toronto, who was not involved in the study. “We’re learning that there’s many regions involved.”
One insight of the new work, Chang says, is that “there are hidden mechanisms that differentiate students who may potentially have math learning difficulties.” Future interventions, she says, could involve teaching kids to think about how they are solving problems and even teaching them different problem-solving strategies.