The aging of memory: A method for the assessment of qualitative changes

Age associated memory changes are traditionally described in terms of quantity of recall. Evidence of qualitative changes associated with aging could lead to a modification of this approach. The primacy and recency effects in serial learning provide a good model to evaluate these qualitative modifications. Our study was designed to investigate modifications of the serial effects in serial learning related to age and modality. We have comparatively investigated, with 120 normal subjects of both sexes, the influence of age and a latent semantic structure, consisting on four taxonomic categories, on the occurrence of primacy and recency effects in a list of verbal stimuli. The presence of a latent structure in the list of stimuli interacted with age in a relearning trial causing the recency effect to disappear more evidently in younger subjects. The same structure did not affect the primacy effect which, on the contrary, was influenced by age only. These results suggest a differential role across age of the automatic processing of working memory versus the role of the semantic-lexical processing of the central processing unit within working memory. They also, demonstrate the importance of age in influencing memory resources which change the quality and quantity of working memory proficiency.