MRI scans show different patterns of brain activity in children with math learning disabilities
Some children have difficulty with mathematics. Now, scientists have identified some specific thought processes and brain regions that might explain why math is a little more difficult for some than others.
In a new study, when presented with simple math problems, children with math learning disabilities were less careful in their responses and did not slow down after making mistakes compared to children with typical math skills. But these differences disappeared when these same children had problems with dots to represent numbers instead of Arabic numerical symbols, researchers report February 9 in the Journal of Neuroscience.
The idea that digital symbols can pose a challenge is not new. “There is a very consistent observation that it is the symbolic processing that is really the struggle of children in difficulty,” says Bert De Smedt, an educational neuroscientist at KU Leuven in Belgium, who was not involved in the study. But subtle differences in how children with learning disabilities in mathematics approach problems, such as not responding cautiously and not slowing down after mistakes, advance understanding of what underlies their difficulties with number symbolshe said.
In the new study, researchers tested second- and third-grade children with and without math learning disabilities by showing them two numbers from 1 to 9 and giving them a few seconds to choose the number they thought was larger. The researchers recorded how long it took the children to answer the questions and observed their brain activities using an MRI scanner. The team analyzed data on children’s performance and behavior during the test using complex mathematical analysis designed to find subtle behavioral patterns, such as how accurately the children responded throughout the experiment and how they changed their behavior after errors. They then compared these behaviors with brain activity.
“We weren’t necessarily interested in how well they performed this task, but how they might approach it differently between the two groups of children,” says Hyesang Chang, a cognitive neuroscientist at San Jose State University in California, who conducted the research at Stanford University.
Using MRI data, Chang and colleagues found that children with learning disabilities’ lack of caution in math when giving answers was associated with lower activity in the middle frontal gyrus, a region of the brain. associated with number processing as well as concentration, impulse control and adaptation to changing circumstances. Meanwhile, failing to slow down after errors was associated with lower activity in the anterior cingulate cortex, a brain region involved in error detection and performance monitoring.
When children were presented with similar problems with dots instead of numbers, these differences disappeared. Children with math learning disabilities had the same amount of activity in the two identified brain areas as children without these disabilities. Chang notes, however, that the analysis is exploratory and cannot show the cause-and-effect relationship between brain activity in these regions and these children’s mathematical abilities.
Identifying these brain regions suggests that explaining differences in math skills is more complex than finding a part of the brain that handles math and numbers. Instead, the study suggests that areas of the brain that process information and detect errors appear to be essential, says Marie Arsalidou, a cognitive developmental neuroscientist at York University in Toronto, who was not involved in the study. “We are learning that many regions are involved.”
According to Chang, one of the lessons of this new work is that “there are hidden mechanisms that differentiate students who may have difficulty learning mathematics.” Future interventions, she says, could include teaching children to think about how they solve problems and even teaching them different problem-solving strategies.
