Forward and backward span for verbal and visuo-spatial data: standardization and normative data from an Italian adult population

The Digit span and Corsi span tasks are frequently used to assess verbal and visuo-spatial short-term memory. Forward versions of these tasks, in which sequences of items of increasing length have to be reproduced in the order they were presented, are believed to primarily evaluate the functioning of the working memory material-specific slave systems (i.e. the phonological loop and the visuo-spatial sketchpad for verbal and visuo-spatial data, respectively). The backward versions of both tasks, in which sequences of items have to be reproduced in the reverse order, are believed to primarily tax Central Executive resources. Here, we report normative data on the forward and backward versions of the Digit span and Corsi span tasks that was collected from 362 healthy Italians ranging in age from 20 to 90 years. The results show a decremental effect of age on performance in all tasks and an ameliorative effect of education in all tasks except the Corsi span backwards. We provide correction grids for age and literacy that derive from results of the regression analyses.