Intraindividual Variability and Level of Performance in Four Visuo-Spatial Working Memory Tasks

Intraindividual variability and level of performance in accuracy of four visuo-spatial working memory tasks were examined in sixty-two young adults. The objective was to study the relationships between intraindividual variability and level of performance and to assess whether intraindividual variability is a useful marker of cognitive functioning. Correlational and factor analyses were performed. Confirmatory factor analyses rejected a two-factor representation, with a first factor representing level of performance and a second factor representing intraindividual variability. The best fitting model specified one factor per task and estimated significant within-task correlations of intraindividual variability residual scores. Overall, these findings are consistent with the view that performance variability provides valuable information independent of level of performance and different from noise.