No abstract

The present study replicated the investigations of Lemaire, Abdi, and Fayol with some modi®cations: the random time interval generation (RIG) task was used and the stimuli were created in another way. The results provide additional evidence for the crucial role of the central executive in the speed of solving both true and false sums and for the role of the phonological loop in solving false sums. However, the ®ndings concerning the role of this slave system in solving true sums were dierent. Possible explanations and limitations of these results are discussed.

In two experiments, we investigated the role of the phonological loop and the central executive in the verification of the complete set of one-digit addition (Experiment 1) and multiplication (Experiment 2) problems. The 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 3 6 = 24) reported until now. The results revealed that this slave system is not involved in verifying simple arithmetic problems, in contrast to the central executive. Furthermore, our results indicated that the split effect is due to the use of two different arithmetic strategies.