Effects of training on the arithmetic problem-size effect: an event-related potential study

This study uses event-related brain potentials to examine the extent to which training in arithmetic calculation increases problem-solution associative strength and reduces the problem-size effect. Participants were presented with a classic equality verification task in two sessions. The problem size was manipulated by using small, medium and large problems. Since the problem-size effect has been related to a modulation of a late positive slow wave and explained in terms of differential frequency of use with problems, practice was expected to modify the amplitude of this positive component. Results showed that the amplitude of the positive slow wave increased with problem size and decreased with practice, suggesting that practice is an important determinant of the problem-size effect.