Alzheimer’s: when you don’t know that you know…
Alzheimer’s patients generally have a propensity to overestimate the strength of their episodic memory which is a category of memory that enables an individual to store and be aware of personally experienced events. A study conducted by researchers in the Cyclotron Research Center of the University of Liege, which was recently published in the magazine Cortex, found that the opposite was true in fact. In addition, they showed that the more the patients had a tendency to make inappropriate judgments, the less grey matter was contained in a particular region of their brain.
Unknown people and celebrities
Numerous works have shown that, in the case of Alzheimer’s, episodic memory is generally altered at an early stage, while semantic memory is preserved for a longer time. The reason for this is that episodic memory involves conscious and controlled processes which are underpinned by a large number of brain regions, while semantic memory is supported by more automatic processes. The question raised by the recent article in Cortex was: how do Alzheimer patients judge their memory processes? Sarah Genon dealt with this question by examining the way in which patients, who in this case were in the early stages of the disease, predicted their own memory performance in terms of their episodic or semantic memory. “We wanted to compare the processes of metacognition for these two types of memory by means of an identical task while using the same type of material”, explains Sarah Genon. This had never been done before. Moreover, the researchers wanted to use a relatively environmental task, one that resembled daily life as much as possible.
(1) Genon S, Simon J, Bahri MA, Collette F, Souchay C, Jaspar M, Bastin C, Salmon E, Relating pessimistic memory predictions to Alzheimer's disease brain structure, Cortex 2016. Pii: S0010-9452(16)30261-1. Doi: 10.1016/j.cortex.2016.09.014.