Verifying simple arithmetic sums and products: Are the phonological loop and the central executive involved?

In two experiments, we investigated thr role of the phonological loop and t he central executive in tire verification of the complete set of one-digit addition (Experiment 1) and multiplication (Expt ri ment 2) problems. Tile focus of the present study was on the contradictory results concerning the contribution of the phonological loop in the verification of true problems (e.g., 8 + 4 = 12 or 4 x 6 = 24) re ported until now. The results revealed that this slave system is not involved in verifying simple arithmetic probl ems, in contrast to the central executive. Furthermore, our results indicat ed that the split effect is due to the use of two different arithmetic stra tegies.