Individual differences in arithmetic skill reflected in event-related brain potentials

We used event-related brain potentials (ERP) to study the problem-size effect in individuals with high and low arithmetic skill. Participants were presented with a classic equality verification task, and problem size was manipulated by using small (e.g., 3 + 4), medium (e.g., 7 + 8) and large problems (e.g., 16 + 29). ERP analyses were time-locked to the onset of the second operand in order to address brain potentials during the production phase. High-skill individuals showed a positive slow wave when solving large problems and no differences in the ERP pattern when solving small and medium problems. In contrast, low-skill individuals showed a positive slow wave when solving medium and large problems. Given that differences between high and low skill individuals have been related to differences in calculation strategies, these results provide further support to the utility of using ERP as a signature of arithmetic strategy.

Research highlights
► Event-related brain potentials might be indicative for fact retrieval vs. procedures use.
► The influence of the problem-size on event-related brain potentials depends on the arithmetical ability.
► High-skill individuals do not show differences in the ERP pattern when they have to solve small and medium additions, but the amplitude is more positive when they have to solve large additions. This result suggests that they use different calculation strategies to solve large and small and medium problems.
► Low-skill individuals show larger ERP amplitude when they have to solve medium and large additions than when they have to solve small addition. This result suggests that they use different calculation strategies to solve small and medium and large problems.