The development of autobiographical memory and links to speed of processing and working memory

It has been extensively documented that there is both age-related and individual variability in children's autobiographical memory abilities (i.e., ability to recount personal past events). Researchers have proposed many factors that could explain this variability, such as verbal ability, maternal conversational style and self concept. However, what is lacking in the literature is the closer examination of basic cognitive skills. This examination is important because social factors explain some but not all of the variance in autobiographical memory abilities. One possible source of variance is speed of processing, that is, the efficiency with which individuals execute cognitive processes. It was hypothesized that fast processors would be more efficient in both encoding and retrieving the details of the event compared to slow processors. Because children get faster in cognitive and perceptual tasks with age, speed of processing is one potential predictor of age-related changes in autobiographical memory abilities. There is also evidence that working memory, the amount of information one can temporarily hold in mind, mediates the relation between speed of processing and memory. In the present research, relations between measures of speed of processing and working-memory taken from Woodcock-Johnson Test of Cognitive Abilities and content of autobiographical narratives in 4-, 6-, and 8-year-old children were examined. Children were interviewed by an experimenter about events from their lives. From these narratives, several measures related to autobiographical memory were obtained. These measures included narrative length, amount and type information provided and quality (completeness or coherence) of the narratives. Results indicated that age-related differences were evident in measures of autobiographical memory, speed of processing and working memory. Speed of processing was a significant predictor of individual differences in the number of event details produced and narrative coherence in the 4-year-old group but not in the older groups. In addition, path analyses indicated that neither speed of processing nor working memory mediated age-related variance in autobiographical memory skills. The results of this study added to the literature on autobiographical memory development by examining the contribution of two basic cognitive mechanisms, and by supplementing the scant literature on autobiographical memory in school-age children.