Measures of visuospatial short-term memory: the Knox Cube Imitation Test and the Corsi Blocks Test compared.

The present investigation analyzes the characteristics of two tasks that have been considered as a measure of visuospatial abilities: The Knox Cube Imitation Test and the Corsi Blocks Test. The former was originally devised by Knox (1913) to diagnose mental retardation in potential immigrants to the United States, while the latter has been specifically designed to be used in neuropsychological practice by Corsi (1972). Although both tasks have been widely used in the past, there is little empirical research investigating the characteristics of these tasks from a theoretical point of view. In order to do so, we carried out two parallel experiments in which both tasks were presented in a baseline condition as well as in association with three different concurrent tasks (i.e., articulatory suppression, spatial tapping, and random generation) supposed to tap the various components of working memory. Results showed that neither of the tasks can be considered as a pure measure of visuospatial processing and that, at the same time, it is necessary to reconsider the architecture of working memory in order to suggest a more integrated functioning of the system.