Increased activity in the hippocampus, a brain region implicated in memory, marks the change in strategy as children grow, moving from solving arithmetic problems by counting, to a more efficient strategy of using their memory, reports a paper published this week in Nature Neuroscience.
Shaozheng Qin and colleagues used functional magnetic brain imaging to track activity in the hippocampus and prefrontal frontal cortex of children, adolescents and young adults as they solved mathematical problems. They recorded brain activity and mathematics strategy twice, approximately a year apart, and found that as children grew older, they were more likely to use a memory based strategy to solve problems, such as knowing common sums (e.g. 4+6 = 10), without having to count it out.
Qin and colleagues report that in comparison to the first session, a year later there was greater activity in the hippocampus, and less activity in the prefrontal and parietal cortex while solving mathematical problems. The prefrontal and parietal cortex are thought to be involved in effortful counting strategies, and this change in the pattern of brain activity as the children grew older parallels the switch to using a memory-based approach. Furthermore, they found that this transition to memory-based problem solving continued into adolescence and adulthood.
These results are important because the use of memory-based approaches to solve problems is known to predict later achievement in mathematics, and children with dyscalculia (a specific developmental disorder that affects arithmetical ability) do not fully transition to memory-based strategies even as they grow older.