Developmental aspects of working and associative memory.

Developmental differences between working and long-term associative memory were evaluated through a cross-sectional age difference study based on data from a memory battery's standardization sample. The scores of 856 children and adolescents ranging from 5 to 17 years of age were compared on memory subtests that assess verbal working and long-term memory. Data were examined using curve fitting and ANOVA procedures that evaluated age group and years of age differences. The major finding was that the developmental trajectories across age differed substantially between the two memory domains. The working memory trajectory was linear until age 11, whereas the long-term memory trajectory was curvilinear with an inflection point at age 8. Both trajectories plateaued after age 11. ANOVAs produced significant interactions between tests of working and associative memory with age, supporting the view that the age trajectories had differing courses. The results are discussed in terms of neurobiological implications for the two memory systems studied.