Adult Age Differences in the Forgetting of Verbal Material Over Extended Time Intervals
Sophie de Selliers Dissertation 2009.doc (679Kb)
de Selliers, Sophie
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It is widely accepted that older participants do not perform as well as their younger counterparts on tasks of memory. Yet while the research on forgetting is extensive, the literature is inconclusive with regards to forgetting and increasing age. The goal of the present study was to clarify the existence of age-related differences in forgetting. Using semantically related and un-related word lists in a verbal free recall memory task, this study examined the forgetting rates of older and younger participants over extended time intervals, in an attempt to determine whether older participants demonstrate an increased rate of forgetting compared to their younger counterparts, or whether deficits in performance are actually due to deficits in acquisition. The role of semantic organization on forgetting rates was also examined. Rate of forgetting was measured as a percentage of words initially recalled, at time intervals of 30 minutes, 24 hours, and seven days. Results showed that older participants forgot more words than the younger participants, with a critical period for forgetting in the elderly appearing between 30 minutes and 24 hours. Although older participants demonstrated a mild acquisition deficit, this did not account for the deficit in memory performance. Semantic organization was also found to have no differential age effect. The increased forgetting demonstrated by older participants in the first 24 hours is indicative of an impairment in the consolidation process of the elderly, which manifests itself as a 24 hour “critical period” of consolidation. The need for further investigation is highlighted, with a focus on the role of retrieval processes and a closer analysis of semantic organization, as well as more incremental and extended time periods.