Factor structure of standard attention tests for children: a distinction between perceptual speed and working memory.

From the many tests developed to identify attentional deficits, only a small number is commonly used in practice. The present study aimed at determining the structure of a set of common attention tests, such as a cancellation test, the Stroop and the Digit Span test, in a sample of 390 elementary school children of 9 years old. As attention and reading deficits often co-occur in children, some tests associated with reading ability were added so that a distinction could be made between factors that are indicative for either deficit. A second aim of the study was to investigate the stability of the structure of the set of tests across subpopulations of boys and girls, and across subpopulations that differed according to the order of administration of the tests. Confirmatory factor analyses showed that the structure of the tests could be adequately described by four correlated factors. In addition, the structure appeared to be highly stable across the subpopulations. The attention tests had their major loadings on three factors, namely Naming Speed, Visual Search and Memory Span. The reading tests generally loaded on Naming Speed and Verbal Learning. As Naming Speed and Visual Search were highly correlated, the major conclusion of the study is that the general capabilities measured by common attention tests are either speed or memory span.