False memories refer to the idea that individuals recall events they have never experienced or episodes that have really occurred but with altered proceedings (Roediger & McDermott, 1995). An increase of false memories produced is observed in normal aging and in Alzheimer’s disease.
Several studies have examined the role of the inhibitor system in the generation of false memories; Inhibition can be altered within normal aging and can sometimes be affected very early in the AD (Ergis, Gely-Nargeot, & Van der Linden, 2005). Among these studies, we found the one of Lövdén (2003) who postulated the existence of an indirect influence of the decline of the inhibitor system on the production of false memories, by accentuating the alteration of episodic memory in healthy elderly people. El Haj and Allain (2012) and El Haj, Fasotti and Allain (2012) were more specifically interested in a process of the episodic memory system, named source monitoring. They emphasized that the decline in source monitoring is related tothe alteration of inhibition in normal aging and AD. Following this discovery, they suggested that the deterioration of source monitoring could be implicatedin the production of false memories.
As a part of our research, we have therefore been interested in the possible indirect influence of inhibition on the production of false memories, particularly through the performance in source monitoring of elderly subjects and patients with an Alzheimer’s disease. We also found that no previous research had been based on a cognitive inhibition model to investigate the link between this inhibitor process and the production of false memories. We have therefore used the model developed by Lustig, Hasher, and Zacks (2007) to determine which inhibitory function, among the access, deletion, and restraint functions, is more particularly involved in the indirect influence of inhibition on generation of false memories in patients with AD and in healthy older adults. At the same time, we explored the effect of normal cognitive aging and AD on the three inhibitory functions, the source monitoring and the production of false memories.
Our study was conducted with seven patients diagnosed with AD, ten healthy seniors and ten young adults. We evaluated thethree cognitive functions with different tests based on the protocol proposed by Kefi (2000). The deletion function was evaluated with TMT A and B, the access function with the reading task in the presence of distractors, and the restraint function was apprehended with the Hayling Test. The three types of source monitoring, namely internal control, external control and reality control, were apprehended using the source monitoring task developed by El Haj and Allain (2012). Finally, the production of DRM was estimated with the version of the DRM paradigm proposed by Evrard, Gilet, Colombel, Dufermont and Corson (2018).
We observed an effect of normal ageing on all inhibitory functions, but we found that only the access and deletion functions were impacted by the AD. For source monitoring, older participants were more altered than young person during external control, and patients with AD were more disturbed than older participants during internal control. Finally, an increase of the production of false memories was observed with the advance of age. However, the production of false memories of the subjects with AD didn’t differ from those of the elderly. Moreover, our data did not allow us to highlight an indirect influence of the three inhibitory functions on the production of false memories, through the performance in source monitoring, and this in the elderly, patients Alzheimer’s and young adults. However, a direct link between the access function and the production of false memories was found in healthy seniors and participants with an AD. We also found a direct influence of the restraint function on the production of false memories of young adults. This therefore suggests rather a direct that an indirect influence of inhibition on the generation of false memories.
We can emphasize that correlation scores tending to a significative effect has been obtained between the deletion function and internal control, as well as between this type of control and the production of false memories in healthy elderly. This leads in the direction of our hypothesis, suggesting an indirect influence of inhibition on the production of false memories. It would therefore be interesting to duplicate this research with larger samples in order to see if we could obtain significant and not trend links between these processes. In addition, reproducing this research with larger samples in each of our groups would make our statistical analyses more powerful, and would allow us to confirm or disprove the results of this study.
Keywords:
– Alzheimer’s disease : Maladie d’Alzheimer
– Normal cognitive aging: Vieillissement cognitif normal
– Cognitive inhibition: Inhibition cognitive
– Source monitoring: Contrôle de la source
– False memories: Faux souvenirs
Words I have learned:
– the access function : la fonction d’accès
– the deletion function : la fonction de suppression
– the restraint functions: la fonction de freinage
Bibliography:
El Haj, M., & Allain, P. (2012). Relations entre contrôle de la source en mémoire épisodique et fonctionnement exécutif dans le vieillissement normal.Gériatrie et Psychologie Neuropsychiatrie du Vieillissement, 10(2),197–205. https://doi.org/10.1684/pnv.2012.0342
El Haj, M., Fasotti, L., &Allain, P. (2012). Source monitoring in Alzheimer’s Disease. Brain and Cognition, 80(2), 185–191. https://doi.org/10.1016/j.bandc.2012.06.004
Ergis, A.-M., Gely-Nargeot, M.-C., & Van der Linden, M. (2005). Les troubles de la mémoire dans la maladie d’Alzheimer. Marseille : Solal.
Evrard, C., Gilet, A. L.,Colombel, F., Dufermont, E., & Corson, Y. (2018). Now you make false memories; now you do not: the order of presentation of words in DRM lists influences the production ofthe critical lure in Alzheimer’s disease. Psychological research, 82(2), 429-438.
Kefi, M.Z. (2000). Etude des fonctions de l’inhibitioncognitive chez des patients frontaux. (Mémoire de Diplôme d’EtudesApprofondies en Neuropsychologie non publié). Université Paul-Sabatier,Toulouse III.
Lövdén, M. (2003). Theepisodic memory and inhibition accounts of age-related increases in falsememories: A consistency check. Journal of Memory and Language, 49(2),268–283. https://doi.org/10.1016/S0749-596X(03)00069-X
Lustig, C., Hasher, L., & Zacks, R. T. (2007). Inhibitory deficit theory: Recent developments in a « new view ». Inhibition in cognition, 17, 145-162.
Roediger, H., & McDermott, K. (1995).Creating False Memories: Remembering words not presented in lists. Journalof Experimental Psychology: Learning, Memory, and Cognition, 21(4), 803‑814. https://doi.org/10.1037/0278-7393.21.4.803
Anaïs RAUD – M2 PPCECC