An Impairment of Prospective Memory in Mild Alzheimer’s Disease: A Ride in a Virtual Town

Abstract

Objective: Research suggests that prospective memory (PM) is impaired from the very early stages of Alzheimer’s disease (AD). We sought to further characterize this impairment in patients with mild AD, using a virtual reality (VR) task to provide ecological assessment of PM. Methods: Fifteen cognitively normal older individuals (76.47 years old ± 4.14, MMSE: 28.80 ± 1.21), and 17 patients with mild AD (79.29 years old ± 4.45, MMSE: 22.82 ± 2.83) were asked to recall the prospective and retrospective components of seven intentions in a virtual town task. Six intentions were event-based, where the prospective cue was either highly (three intentions) or weakly (three intentions) associated with the retrospective component. The remaining intention was time-based. All participants completed a neuropsychological assessment of episodic memory, semantic memory and executive functioning. Non-parametric tests were used to compare the two groups on the different intentions types and components. Correlations between cognition and PM scores were then realized to further understand the cognitive correlates of the PM impairment in patients with AD. Results: Overall, patients with Alzheimer disease recalled fewer intentions than controls, with the retrospective component and time-based intentions being the most challenging for them. The strength of the association between the prospective and retrospective components, however, had no effect on their performance. Event-based PM impairment, as well as deficit in the recall of prospective component correlated with memory and executive functions performance. Conclusion: PM is impaired in AD. Both automatic and controlled processes of PM retrieval are disturbed. This study also confirms the reliability of VR for assessing complex cognitive functions such as PM.

Head-Mounted Display-Based Application for Cognitive Training

“…VR has been proven to provide fairer results with age, so assessments applied at different ages showed variations on the classical exams, but not on the memory VR exam [ 42 ]. VR has also been used to evaluate complex cognitive functions such as prospective memory, in the case of [ 43 ] authors confirmed the deterioration of this memory in the early stages of Alzheimer’s disease. In this way, VR has been inserted as a memory diagnosis and rehabilitation tool, but there are few IVR studies aimed at evaluating memory, which motivates the development of applications with different levels of immersion [ 44 ].…”

Being in the Past and Perform the Future in a Virtual World: VR Applications to Assess and Enhance Episodic and Prospective Memory in Normal and Pathological Aging

“…Link-EB produced better performance than noLink-EB and TB, highlighting the importance of the association processes between PC and RC for effective PM. Similarly, Lecouvey et al (2019) explored in VR the effects of mild AD on PM, showing that both the PM components are significantly compromised in AD patients, but RCs of intentions are altered before PCs. These data supported the hypothesis that early impairments of EM have a great impact on the execution of PM tasks in AD.…”

“…This VR approach is a more realistic tool that could help to better highlight planning processes, motivational aspects, time estimation, or eventual difficulties in dual-task processes in PM impairments in everyday life (Gonneaud et al, 2014 ; Lecouvey et al, 2019 ). Also, this approach could be useful to provide more efficient therapeutic interventions (Meijer et al, 2009 ) and a better measure of training effectiveness concerning less naturalistic performance.…”

A Fully-Immersive and Automated Virtual Reality System to Assess the Six Domains of Cognition: Protocol for a Feasibility Study

“…Without a three-dimensional environment, these VR systems are not be able to create a fully-immersive experience where the person has the sense of “being there,” thus being unable to simulate tasks that sufficiently mimic real life to assess a person's cognitive function (Strong, 2020 ). Moreover, these systems can only assess limited number of cognitive domains in one setting and lack language-domain assessment (Fernandez Montenegro and Argyriou, 2017 ; Seo et al, 2017 ; Lecouvey et al, 2019 ).…”