The modeling of temporary storage and its effect on fluid intelligence: Evidence from both Brown–Peterson and complex span tasks

The aim of the current study was to achieve a purified representation of the capacity for the temporary storage of information and to examine its relationship with fluid intelligence by means of a novel approach combining experimental manipulations and statistical modeling. A sample of 221 university students completed versions of the Brown–Peterson task and of the complex span task. In each task we manipulated the demands to storage capacity by including three treatment levels in the storage subtask. The distractor subtask was also manipulated. The fixed-links modeling approach was applied to separate the core process representing temporary storage from the auxiliary processes and to link them to measures of fluid intelligence. The results revealed a high correlation between the temporary-storage latent variables of the two tasks. The correlation between fluid intelligence and temporary storage was substantial for both storage tasks. A general temporary-storage latent variable extracted from the two storage tasks accounted for over a quarter of the variance of fluid intelligence. In contrast, the effect of the distractor subtask on memory performance proved to be independent of fluid intelligence. These results suggest that temporary storage is a relevant cognitive process regarding fluid intelligence, whereas coping with distraction is not.