Long-Term Retention Deficit Involvement in Prodromal Alzheimer’s Disease

Since episodic memory impairments have been pointed out as the first symptom to occur in Alzheimer’s disease (AD), what have we learned about the nature of those impairments? There is still no consensus regarding the cognitive substrates of the inaugural memory disorder. Encoding, storage as well as retrieval or recognition had all been pointed out, but a compound deficit has also been suggested [1]. We can point out several reasons. First, research has mainly focused on memory measures that could predict incident dementia, therefore study designs generally do not allow inference about the cognitive processes engaged in the tasks used (e.g. [2]). Secondly, concepts of encoding, storage, retrieval are quite rarely defined in literature, leading to conceptual and operational overlaps between so-called “learning, acquisition, encoding, storage, consolidation, etc.”. Nonetheless, given the importance of memory deficit for diagnosis, a detailed knowledge of underlying cognitive features of the memory deficit is required [3]. How to improve such process dissociation? The first method consists in the development of specific paradigms. Free and Cued Selective Reminding Test [4] was developed to target genuine memory deficits in dementia, and it is the most popular screening tool in French memory clinics. Unfortunately, studies using FCSRT did not achieve any clear consensus. Noteworthy, coordination between encoding and