Identifying neurodevelopmental stages of memory from childhood through adolescence with cluster analysis

Abstract

Cluster analysis can be used to interpret large datasets, though there are numerous theoretical and methodological issues to consider first. This chapter walks the reader through a step-by-step example by interpreting a memory dataset to establish developmental patterns and relationships of memory in a sample of youth who completed a nationally representative memory battery. Confirmatory factor analysis supported the presence of verbal and nonverbal long-term, as well as short-term and working memory, factors in the sample. Special note is made of how the results of a cluster analysis were used to interpret the dataset and its strengths and limitations of findings. Results from the analyses identified three age stages (5-8, 9-11, 12-19 years) with distinct trajectories of memory development. Comparisons of the age groups on factors identified interaction effects between factors and developmental stages. Post hoc analyses further indicated that short-term, working, and long-term nonverbal memories develop in a linear fashion, while verbal memory is lower in younger children compared to the other factors and higher in the middle children. No differences among the factors were identified in the older group. These results provide additional insight concerning the development stages of memory and support evidence of differential trajectories among components and demonstrate to the reader an empirical way to use cluster analysis within a neuropsychological dataset.