Entraînement de la mémoire chez les personnes âgées ayant une plainte mnésique : contribution de la réalité virtuelle au transfert et rôle de l’attention

The prodromal stages of Alzheimer’s disease offer a critical window of opportunity for interventions aiming to optimize cognition through cognitive training, thus potentially limiting cognitive impairment. However, the transfer effects of cognitive interventions remain uncertain. The work of this thesis focuses on the improvement of the ecological validity of memory training in order to foster its transfer effects, either through the use of immersive virtual reality (VR), or by adding an inhibition task involving ambient verbal noise. The first study (Chapter II) aimed to design and evaluate the feasibility and validity of the Virtual Shop (i.e., La boutique virtuelle). First, a VR task was designed to evaluate memory in a context similar to everyday life. Twenty young adults and 19 older adults completed the task with sufficient variability in the results, thus supporting its feasibility. The performance of the young adults was higher than that of the older adults. Second, in 35 older individuals with subjective cognitive decline, the scores obtained in VR were correlated with those obtained on a measure of episodic memory and on a self-reported measure of daily memory. These results support the construct validity and ecological validity of the Virtual Shop. The second study (Chapter III) aimed to examine the transfer effects of memory training, using VR as a tool for promoting and measuring context transfer, and exploring the relationship between dose and response. The transfer effects in VR were compared to those obtained on a self-reported questionnaire. Forty individuals with memory complaints completed six training sessions on the method of loci. Half of the participants also practiced the method in the Virtual Shop, while the others performed an exercise of visual detection. Following training, the performance of both groups improved in the VR tasks, but not on the questionnaire. These effects suggest a transfer of the benefits of training to everyday tasks, and that VR is sensitive to these transfer effects. Adding VR exercises or increasing the training dose does not appear to increase the transfer effects. The third study (Chapter IV) aimed to assess whether memory training could be more effective when combined with exercises in the context of auditory inhibition. Forty older adults with memory complaints completed six training sessions on the method of loci. Participants learned the method of loci during sessions 1-3. In sessions 4-6, half of the participants completed exercises in the presence of verbal noise, of which the level of distractibility gradually varied. Following training, everyone showed improvement in word recall, in both the silent and noisy conditions, until eliminating the deleterious effect of noise. The results suggest that training in the method of loci is sufficient to improve memory performance in the context of verbal noise. Training in noisy environments does not seem to lead to more benefits. This thesis helped support the feasibility and validity of the use of VR in the context of memory evaluation in young and older adults and to put forth the transfer effects following memory training. However, it also highlights the challenges inherent in improving intervention protocols.

Keyphrases: attention, inhibition, cognitive training, memory, attention, inhibition, noise, virtual reality, method of loci, transfer, aging, memory complaint