MEMORY DISORDERS IN ALZHEIMERS-DISEASE AND THE ORGANIZATION OF HUMAN-MEMORY

The Squire and Zola-Morgan parallel organization model of the memory a nd the Tulving hierarchical model were developed mainly through the st udy of amnesic patients. The predictions of these two models are diffe rent, the first being more open to double dissociations and less restr ictive than the second. Alzheimer's Disease is characterized by a diff erential impairment of the memory systems and by an interindividual va riability which may take the form of dissociations between preserved a nd disturbed abilities in some patients. The objective of this study w as to use the memory dysfunctions of patients with AD to test the vali dity of the two models. Analysis of the group data provided an average profile of memory disturbance consistent both with much of the data g iven in AD literature and with the two models. Using a multiple single -case strategy, we demonstrated several simple dissociations which are for the greater part compatible with the two models. Two of the disso ciations underline the limits of the Tulving model, which otherwise ac counts for a lot of results. The study supports the relevance of AD fo r the understanding of the cognitive architecture of the human memory.