Children's Higher Order Cognitive Abilities and the Development of Secondary Memory
De Alwis, Duneesha, Myerson, Joel, Hershey, Tamara, Hale, Sandra, Psychonomic Bulletin & Review
The relations between higher cognitive abilities and immediate and delayed recall were studied in 57 children (6-16 years of age). The participants were tested repeatedly on free recall of a supraspan list (Children's Memory Scale), and their fluid ability was also assessed (Woodcock-Johnson III Spatial Relations). Consistent with Unsworth and Engle's (2007) account of the relation between memory and higher order cognition, the children's fluid ability was significantly correlated with retrieval from secondary memory, regardless of whether it was measured using immediate or delayed recall. Multiple regression analyses provided further support for this view, revealing that measures of immediate and delayed retrieval from secondary memory accounted for the same variance in the children's fluid ability.
Children's memory and higher order cognitive abilities both improve with age, but the nature of the relation between these two developmental trends is not yet well understood. Much recent research on higher order cognitive abilities in adults has been focused on working memory's contribution to these abilities, and developmental researchers have also pursued this approach (e.g., Bayliss, Jarrold, Baddeley, & Gunn, 2005; Kail, 2007). Working memory tasks (e.g., reading span, operation span), sometimes termed complex span tasks, require processing, as well as short-term storage of information. This processing requirement distinguishes complex span tasks from simple span tasks, which require only storage. Complex span tasks have been reported to be better predictors of higher order abilities than are simple span tasks (e.g., Engle, Tuholski, Laughlin, & Conway, 1999; Swanson & Howell, 2001). However, recent research with both children (e.g., Bayliss et al., 2005) and adults (e.g., Colom, Shih, Flores-Mendoza, & Quiroga, 2006) has raised questions regarding this distinction.
Unsworth and Engle (2007) recently proposed a twocomponent theory that takes a new approach to this issue. According to Unsworth and Engle (2007), both simple and complex span tasks involve maintaining items in primary memory and retrieving them from secondary memory, but they differ in the relative contributions made by these two processes. They suggest that retrieval from secondary memory becomes important to working memory performance under two conditions: (1) when processing that is interleaved between the encoding of successive memory items displaces those items from primary memory (as on complex span tasks) and (2) when the number of items exceeds the capacity of primary memory, even if the task involves only storage (as in recall of supraspan lists). Although both primary and secondary memory are hypothesized to play a role in the correlation between working memory and higher order cognition, Unsworth and Engle (2007) presented data showing that primary and secondary memory abilities are largely independent of each other and that the unique contribution of secondary memory to higher order cognition is roughly twice that of primary memory.
If Unsworth and Engle (2007) are correct, developmental and individual differences in children's higher order cognitive abilities should be more strongly related to their secondary memory than to their primary memory abilities. In the present study, we tested this hypothesis. To measure children's primary and secondary memory, we made use of the long-standing idea (reiterated by Unsworth and Engle, 2007) that in immediate free recall, items from the beginning of a supraspan list are retrieved from secondary memory, whereas items from the end tend to be retrieved from primary memory (Waugh & Norman, 1965; for recent neuroimaging evidence, see Talmi, Grady, Goshen-Gottstein, & Moscovitch, 2005). Unsworth and Engle (2007) also assumed that the capacity of primary memory is approximately four items (Cowan, 2001) and that secondary memory involvement in simple storage tasks depends on the extent to which list length exceeds that number. …