Difficulties in working memory updating in individuals with intellectual disability

Background Despite the critical role attributed to working memory (WM) updating for executive functions and fluid intelligence, no research has yet been carried out on its specific role in the vital case of fluid intelligence weakness, represented by individuals with intellectual disability (ID). Furthermore, the relationship between updating and other WM functions has not been considered in depth. Method The current study examines these areas by proposing a battery ofWM tasks (varying in degree of active attentional control requested) and one updating task to groups of ID individuals and typically developing children, matched for fluid intelligence performance (on CPM: Coloured Progressive Matrices). Results Comparison between the group of ID individuals and a group of typically developing children showed that, despite being matched on the Raven test, the updating measure significantly differentiated the groups as well as theWM complex span. Furthermore, updating proved to be the task with the greatest power in discriminating between groups. Conclusions Our results confirm the critical importance of the demand for active attentional control in explaining the role ofWM in fluid intelligence performance, and in particular show that updating information inWM plays an important, specific role in the distinction between typically developing children and ID individuals.