From the eigthies, memory disorders in Alzheimer’s disease (AD) led to a detailed cognitive analysis aimed at identifying specific processes. In addition, these studies contributed to the modelisation of human memory by the characterization of different memory systems and their relationships.
The first part of this paper is an overview of the memory deficits in AD and stresses particular cognitive phenomena. Several examples are developped in the domains of semantic memory (hyperpriming and hypopriming) and autobiographical memories. Recent results highligt the presence of severe autobiographical amnesia in all neurodegenerative, though with contrasting profiles: Ribot’s gradient in AD (showing that remote memories are better preserved than recent ones), reverse gradient in smantic dementia and no clear gradient in the frontal variant of fronto-temporal dementia.
The second part of the paper reports advances in cognitive neurosciences aiming at disclosing the cerebral substrates of the cognitive deficits in AD. Functional imaging techniques are the most informative. While showing dysfunctions in an extended network, they emphasize the selectivity of cerebral damages that are at the root of very specific cognitive dysfunctions, coming close to the concpts of of cognitive neuropsychology; Moreover, they unravel the existence of compensatory mechanisms, wich until recently were clearly missing in the studies of neurodegenerative diseases.
These researches lead to a wide conception of human memory, not limited to simple instrumental processes (encoding, storage, retrieval), but necessarily covering models of identity and continuity of the subject, which interact in a dynamic way with eminently changing memory representations.
© 2006 Elsevier Masson SAS. Tous droits réservés.