Using virtual reality to characterize episodic memory profiles in amnestic mild cognitive impairment and Alzheimer's disease: Influence of active and passive encoding

Unveiling the Evolution of Virtual Reality in Medicine: A Bibliometric Analysis of Research Hotspots and Trends over the Past 12 Years

BACKGROUND

Virtual reality (VR), widely used in the medical field, may affect future medical training and treatment. Therefore, this study examined VR's potential uses and research directions in medicine.

METHODS

Citation data were downloaded from the Web of Science Core Collection database (WoSCC) to evaluate VR in medicine in articles published between 1 January 2012 and 31 December 2023. These data were analyzed using CiteSpace 6.2. R2 software. Present limitations and future opportunities were summarized based on the data.

RESULTS

A total of 2143 related publications from 86 countries and regions were analyzed. The country with the highest number of publications is the USA, with 461 articles. The University of London has the most publications among institutions, with 43 articles. The burst keywords represent the research frontier from 2020 to 2023, such as "task analysis", "deep learning", and "machine learning".

CONCLUSION

The number of publications on VR applications in the medical field has been steadily increasing year by year. The USA is the leading country in this area, while the University of London stands out as the most published, and most influential institution. Currently, there is a strong focus on integrating VR and AI to address complex issues such as medical education and training, rehabilitation, and surgical navigation. Looking ahead, the future trend involves integrating VR, augmented reality (AR), and mixed reality (MR) with the Internet of Things (IoT), wireless sensor networks (WSNs), big data analysis (BDA), and cloud computing (CC) technologies to develop intelligent healthcare systems within hospitals or medical centers.

The use of virtual reality as a perspective-taking manipulation to improve self-awareness in Alzheimer's disease

Lack of awareness of symptoms or having a condition referred to as anosognosia is a common feature of individuals with Alzheimer's Disease (AD). Previous literature on AD reported difficulties in evaluating self-abilities, often showing underestimation of limitations. There is increasing evidence that the perspective through which information is presented may moderate the performance appraisal and that anosognosia in AD might be a consequence of a deficit in assuming a third-person perspective. In this context, some studies showed that subjects may better recognize self-and other-difficulties when exposed to a third-person perspective. Considering the variety of approaches aiming to investigate the lack of awareness, there is still a scarcity of methods that provide great ecological validity and consider more than one facet of awareness, thus failing to offer more accurate evaluations of daily experiences. The present paper primarily addresses the theme of the multidimensional character of awareness of abilities in AD and the effect of perspective-taking on its trajectories. The focus turns to virtual reality as a promising tool for a greater evaluation of perspective-taking and self-awareness. Particularly, these systems offer the possibility to involve users in cognitive and sensorimotor tasks that simulate daily life conditions within immersive and realistic environments, and a great sense of embodiment. We propose that virtual reality might allow a great level of complexity, veracity, and safety that is needed for individuals with AD to behave according to their actual abilities and enable to explore the liaison between the subject's viewpoint, performance, and self-evaluation. In addition, we suggest promising clinical implications of virtual reality-based methods for individualized assessments, investigating specific impacts on subjects' life and possible improvements in their awareness.

Mobile and wearable technologies for persons with disabilities: a bibliometric analysis (2000-2021)

PURPOSE

This study uses a bibliometric approach to analyse the patterns in research related to mobile and wearable technologies for persons with disabilities to evaluate the current state of relevant research.

MATERIALS AND METHODS

A systematic search was done using two strings covering "disability" and "mobile and wearable technologies" in the titles of publications in the Web of Science database. Two researchers independently screened the results for relevant publications. During this process, the inclusion and exclusion criteria were deliberated and refined. An independent researcher checked the screening results against the finalized inclusion and exclusion criteria to ensure that the screening was done consistently.

RESULTS

A total of 2012 out of the 5990 retrieved publications from 2000 to 2022 were included for further analysis. We observed that publications in this area grew exponentially since 2011, almost doubling every 2 years between 2011 and 2015. Universities in the USA were the most active and prominent in relevant publications. Autism is the most researched disability in relation to mobile and wearable technologies. The publications cover both hardware (engineering, electrical and electronic) and software (computer science, theory and methods) technologies used for improving quality of life for persons with disabilities (rehabilitation).

CONCLUSIONS

The majority of publications were from high income countries, indicating the need to study the digital divide among high-, low- and middle-income countries in adopting mobile and wearable technologies for persons with disabilities, especially ways of making these technologies more affordable and accessible to the under-privileged members of the community.

Unveiling the efficacy of the feedback concealed information test in collaborative crime detection

Collaborative crime poses severe social hazards. In collaborative crime scenarios, previous studies have indicated that perpetrators' collaborative encoding can impair the detection efficiency of P300-based complex trial protocols due to the collaborative encoding deficit. The feedback concealed information test (fCIT), a unique variation of the concealed information test, provides participants with feedback on how well they conceal information from memory. The fCIT, which has proven to be highly efficient, detects concealed information using recognition P300 along with feedback-related event-related potentials, and reflects the subject's motivation to conceal. However, no studies have examined the fCIT's effectiveness in identifying collaborative criminals. We propose that the fCIT's efficiency persists in cases of collaborative crime and test this hypothesis using a sample of 48 participants. The participants in the collaborative groups were instructed to have hushed conversations about theft to simulate the collaborative crime process. Subsequently, they completed the fCIT. The findings indicate a significant decline in recognition P300's detection efficiency when participants committed crimes collaboratively. Nevertheless, the detection efficiency of feedback P300 and feedback-related negativity remained high. This study's outcomes illustrate the capacity of the fCIT to detect perpetrators involved in collaborative crime.

Enhancing cognitive flexibility and working memory in individuals with mild cognitive impairment: Exploring the impact of virtual reality on daily life activities

Mild Cognitive Impairment (MCI) serving as a transitional stage between normal aging and dementia. This study aimed to explore the impact of virtual reality (VR) on enhancing cognitive flexibility, working memory, and daily life activities. Forty participants diagnosed with MCI were randomly assigned to either an intervention group (N = 20) or a control group (N = 20). Evaluations were at baseline, post-training, and three months post-training using various cognitive assessment tools. Results showed that the VR-based cognitive rehabilitation significantly improved instrumental activities of daily living performance, visual and verbal working memory, and reduced anxiety and depression symptoms. While cognitive flexibility did not exhibit significant improvement, these findings highlight VR interventions as a potential avenue for improving cognitive and functional aspects, and alleviating psychological symptoms in individuals with MCI. Further research with larger sample sizes and extended follow-up periods is recommended to establish the long-term effectiveness of such interventions.

Getting LOST: A conceptual framework for supporting and enhancing spatial navigation in aging

Spatial navigation is more difficult and effortful for older than younger individuals, a shift which occurs for a variety of neurological, physical, and cognitive reasons associated with aging. Despite a large body of evidence documenting age-related deficits in spatial navigation, comparatively less research addresses how to facilitate more effective navigation behavior for older adults. Since navigation challenges arise for a variety of reasons in old age, a one-size-fits-all solution is unlikely to work. Here, we introduce a framework for the variety of spatial navigation challenges faced in aging, which we call LOST-Location, Orientation, Spatial mapping, and Transit. The LOST framework builds on evidence from the cognitive neuroscience of spatial navigation, which reveals distinct components underpinning human wayfinding. We evaluate research on navigational aids-devices and depictions-which help people find their way around; and we reflect on how navigation aids solve (or fail to solve) specific wayfinding difficulties faced by older adults. In summary, we emphasize a bespoke approach to improving spatial navigation in aging, which focuses on tailoring navigation solutions to specific navigation challenges. Our hope is that by providing precise support to older navigators, navigation opportunities can facilitate independence and exploration, while minimizing the danger of becoming lost. We conclude by delineating critical knowledge gaps in how to improve older adults' spatial navigation capacities that the novel LOST framework could guide to address. This article is categorized under: Psychology > Development and Aging Neuroscience > Cognition Neuroscience > Behavior.

Embodied Spatial Navigation Training in Mild Cognitive Impairment: A Proof-of-Concept Trial

Background

Egocentric and allocentric spatial memory impairments affect the navigation abilities of older adults with mild cognitive impairment (MCI). Embodied cognition research hints that specific aids can be implemented into virtual reality (VR) training to enhance spatial memory.

Objective

In this study, we preliminarily tested 'ANTaging', an embodied-based immersive VR training for egocentric and allocentric memory, compared to treatment as usual (TAU) spatial training in MCI.

Methods

MCI patients were recruited for this controlled trial. A cognitive battery was administered at pre-test, after ten sessions of ANTaging or TAU intervention, and at 3-month follow-up (FU). The primary outcomes were spatial cognition tests (Corsi supra-span, CSS; Manikin test, MT). VR egocentric and allocentric performance was also collected.

Results

We found that ANTaging significantly improved MT scores at FU compared to TAU. CSS slightly improved in both groups. Concerning secondary outcomes, auditory-verbal forgetting significantly improved at post-test in the ANTaging but not TAU group and significantly declined at FU in the TAU but not in the ANTaging group. Global cognition significantly improved at FU for TAU and remained stable for ANTaging. Other tests showed no improvement or deterioration. Clinical significance showed that ANTaging is effective for CSS. Virtual egocentric and allocentric memory performance improved across ANTaging sessions.

Conclusions

ANTaging holds the potential to be superior for improving spatial cognition in MCI compared to TAU. Embodied cognition research provides insights for designing effective spatial navigation rehabilitation in aging.

Bodily and Visual-Cognitive Navigation Aids to Enhance Spatial Recall in Mild Cognitive Impairment

Background

Individuals with mild cognitive impairment (MCI) syndrome often report navigation difficulties, accompanied by impairments in egocentric and allocentric spatial memory. However, studies have shown that both bodily (e.g., motor commands, proprioception, vestibular information) and visual-cognitive (e.g., maps, directional arrows, attentional markers) cues can support spatial memory in MCI.

Objective

We aimed to assess navigation cues for innovative spatial training in aging.

Methods

Fifteen MCI patients were recruited for this study. Their egocentric and allocentric memory recall performances were tested through a navigation task with five different virtual reality (VR) assistive encoding navigation procedures (bodily, vision only, interactive allocentric map, reduced executive load, free navigation without cues). Bodily condition consisted of an immersive VR setup to engage self-motion cues, vision only condition consisted of passive navigation without interaction, in the interactive allocentric map condition patients could use a bird-view map, in the reduced executive load condition directional cues and attentional markers were employed, and during free navigation no aid was implemented.

Results

Bodily condition improved spatial memory compared to vision only and free navigation without cues. In addition, the interactive allocentric map was superior to the free navigation without cues. Surprisingly, the reduced executive load was comparable to vison only condition. Moreover, a detrimental impact of free navigation was observed on allocentric memory across testing trials.

Conclusions

These findings challenge the notion of an amodal representation of space in aging, suggesting that spatial maps can be influenced by the modality in which the environment was originally encoded.

The effects of age on objective and subjective recollection after visiting a virtual apartment

While aging has been associated with decreased retrieval of episodic memory details, subjective ratings about memory quality seem to remain stable. This suggests that subjective memory judgments are based on different information according to age. Here, we tested the hypothesis that older people would rather base their subjective judgments on the retrieval of personal elements (such as emotions and thoughts), whereas younger people would rather base their judgments on the retrieval of event-related elements (such as time, place, and perceptual details). Sixty participants (20 to 79 years old) performed eight actions in a virtual apartment and were then asked to verbally recall each action with a maximum of associated elements and to rate the subjective quality of their memories. The elements reported were classified into "person-related" and "event-related" categories. Executive functions, memory performance on traditional memory tasks, and subjects' perception of memory functioning were also evaluated. Results revealed that aging was associated with reduced retrieval of event-related elements, which was explained by decreasing executive resources. However, age did not affect the retrieval of person-related elements, and the subjective memory judgments of older people were not based on these elements to a greater extent than those of younger people. Finally, our results highlight the value of virtual reality (VR) in memory evaluations since subjects' perception of memory functioning was associated with their performance in the VR task but not in traditional memory tasks.

The role of bodily self-consciousness in episodic memory of naturalistic events: an immersive virtual reality study

Recent studies suggest that the human body plays a critical role in episodic memory. Still, the precise relationship between bodily self-consciousness (BSC) and memory formation of specific events, especially in real-life contexts, remains a topic of ongoing research. The present study investigated the relationship between BSC and episodic memory (EM) using immersive virtual reality (VR) technology. Participants were immersed in an urban environment with naturalistic events, while their visuomotor feedback was manipulated in three within-subjects conditions: Synchronous, Asynchronous, and No-body. Our results show that asynchronous visuomotor feedback and not seeing one's body, compared to synchronous feedback, decrease the sense of self-identification, self-location and agency, and sense of presence. Moreover, navigating in the Asynchronous condition had a detrimental impact on incidental event memory, perceptual details, contextual association, subjective sense of remembering, and memory consolidation. In contrast, participants in the No-Body condition were only impaired in egocentric spatial memory and the sense of remembering at ten-day delay. We discuss these findings in relation to the role of bodily self-representation in space during event memory encoding. This study sheds light on the complex interplay between BSC, sense of presence, and episodic memory processes, and strengthens the potential of embodiment and VR technology in studying and enhancing human cognition.

The role of sense of presence in expressing cognitive abilities in a virtual reality task: an initial validation study

There is a raised interest in literature to use Virtual Reality (VR) technology as an assessment tool for cognitive domains. One of the essential advantages of transforming tests in an immersive virtual environment is the possibility of automatically calculating the test's score, a time-consuming process under natural conditions. Although the characteristics of VR can deliver different degrees of immersion in a virtual environment, the sense of presence could jeopardize the evolution of these practices. The sense of presence results from a complex interaction between human, contextual factors, and the VR environment. The present study has two aims: firstly, it contributes to the validation of a virtual version of the naturalistic action test (i.e., virtual reality action test); second, it aims to evaluate the role of sense of presence as a critical booster of the expression of cognitive abilities during virtual reality tasks. The study relies on healthy adults tested in virtual and real conditions in a cross-over research design. The study's results support the validity of the virtual reality action test. Furthermore, two structural equation models are tested to comprehend the role of sense of presence as a moderator in the relationship between cognitive abilities and virtual task performance.

Current development of biosensing technologies towards diagnosis of mental diseases

The biosensor is an instrument that converts the concentration of biomarkers into electrical signals for detection. Biosensing technology is non-invasive, lightweight, automated, and biocompatible in nature. These features have significantly advanced medical diagnosis, particularly in the diagnosis of mental disorder in recent years. The traditional method of diagnosing mental disorders is time-intensive, expensive, and subject to individual interpretation. It involves a combination of the clinical experience by the psychiatrist and the physical symptoms and self-reported scales provided by the patient. Biosensors on the other hand can objectively and continually detect disease states by monitoring abnormal data in biomarkers. Hence, this paper reviews the application of biosensors in the detection of mental diseases, and the diagnostic methods are divided into five sub-themes of biosensors based on vision, EEG signal, EOG signal, and multi-signal. A prospective application in clinical diagnosis is also discussed.

Ethical issues when using digital biomarkers and artificial intelligence for the early detection of dementia

Dementia poses a growing challenge for health services but remains stigmatized and under-recognized. Digital technologies to aid the earlier detection of dementia are approaching market. These include traditional cognitive screening tools presented on mobile devices, smartphone native applications, passive data collection from wearable, in-home and in-car sensors, as well as machine learning techniques applied to clinic and imaging data. It has been suggested that earlier detection and diagnosis may help patients plan for their future, achieve a better quality of life, and access clinical trials and possible future disease modifying treatments. In this review, we explore whether digital tools for the early detection of dementia can or should be deployed, by assessing them against the principles of ethical screening programs. We conclude that while the importance of dementia as a health problem is unquestionable, significant challenges remain. There is no available treatment which improves the prognosis of diagnosed disease. Progression from early-stage disease to dementia is neither given nor currently predictable. Available technologies are generally not both minimally invasive and highly accurate. Digital deployment risks exacerbating health inequalities due to biased training data and inequity in digital access. Finally, the acceptability of early dementia detection is not established, and resources would be needed to ensure follow-up and support for those flagged by any new system. We conclude that early dementia detection deployed at scale via digital technologies does not meet standards for a screening program and we offer recommendations for moving toward an ethical mode of implementation. This article is categorized under:Application Areas > Health CareCommercial, Legal, and Ethical Issues > Ethical ConsiderationsTechnologies > Artificial Intelligence.

Encoding of everyday objects in older adults: Episodic memory assessment in virtual reality

Introduction

Age-related decline in episodic memory performance in otherwise healthy older adults is indisputably evident. Yet, it has been shown that under certain conditions episodic memory performance in healthy older adults’ barely deviates from those seen in young adults. Here we report on the quality of object encoding in an ecologically valid, virtual-reality based memory assessment in a sample of healthy older and younger adults with comparable memory performance.

Methods

We analyzed encoding by establishing both a serial and semantic clustering index and an object memory association network.

Results

As expected, semantic clustering was superior in older adults without need for additional allocation of executive resources whereas young adults tended more to rely on serial strategies. The association networks suggested a plethora of obvious but also less obvious memory organization principles, some of which indicated converging approaches between the groups as suggested by a subgraph analysis and some of which indicated diverging approaches as suggested by the respective network interconnectivity. A higher interconnectivity was observed in the older adults’ association networks.

Discussion

We interpreted this as a consequence of superior semantic memory organization (extent to which effective semantic strategies diverged within the group). In conclusion, these results might indicate a diminished need for compensatory cognitive effort in healthy older adults when encoding and recalling everyday objects under ecologically valid conditions. Due to an enhanced and multimodal encoding model, superior crystallized abilities might be sufficient to counteract an age-related decline in various other and specific cognitive domains. This approach might potentially elucidate age-related changes in memory performance in both healthy and pathological aging.

Usability of an Embodied CAVE System for Spatial Navigation Training in Mild Cognitive Impairment

Individuals with mild cognitive impairment (MCI) usually report navigation and spatial memory impairments. Spatial navigation is an embodied process that requires the active involvement of both physical (e.g., motor commands and proprioception) and cognitive (e.g., decision-making and mental rotation) information. Immersive virtual reality (IVR) is a valuable tool that employs this information as real-world navigation does. Given the crucial impact of spatial navigation on daily life, research should focus on ways to enhance it. Though they are still in their development, contemporary IVR methods for spatial navigation training in MCI seem promising. In this usability study, eight patients with MCI syndrome tested an IVR spatial navigation training demo and interacted with the CAVE using active stereo glasses, a foot-motion pad, and a joypad. During the demo, users were asked to report their impressions on the IVR training using the thinking-aloud procedure. Moreover, questionnaires regarding usability, presence and cybersickness were administered at the end of the experience. Our results show that the first version of this system is usable by the patients even if most of them did not have experience with PC/IVR. The system provided a moderate sense of spatial presence and limited negative effects. Issues found during the thinking-aloud procedure concerned the visual aspects, which affected the interaction user-system. Participants reported that they needed more practice with the foot-motion pad even though the overall experience was positively evaluated. Identifying these critical features was essential to develop an improved version of the current system.

Automatic Detection of Cognitive Impairment with Virtual Reality

Cognitive impairment features in neuropsychiatric conditions and when undiagnosed can have a severe impact on the affected individual's safety and ability to perform daily tasks. Virtual Reality (VR) systems are increasingly being explored for the recognition, diagnosis and treatment of cognitive impairment. In this paper, we describe novel VR-derived measures of cognitive performance and show their correspondence with clinically-validated cognitive performance measures. We use an immersive VR environment called VStore where participants complete a simulated supermarket shopping task. People with psychosis (k=26) and non-patient controls (k=128) participated in the study, spanning ages 20-79 years. The individuals were split into two cohorts, a homogeneous non-patient cohort (k=99 non-patient participants) and a heterogeneous cohort (k=26 patients, k=29 non-patient participants). Participants' spatio-temporal behaviour in VStore is used to extract four features, namely, route optimality score, proportional distance score, execution error score, and hesitation score using the Traveling Salesman Problem and explore-exploit decision mathematics. These extracted features are mapped to seven validated cognitive performance scores, via linear regression models. The most statistically important feature is found to be the hesitation score. When combined with the remaining extracted features, the multiple linear regression model resulted in statistically significant results with R2 = 0.369, F-Stat = 7.158, p(F-Stat) = 0.000128.

VR for Cognition and Memory

This chapter will provide a review of research into human cognition through the lens of VR-based paradigms for studying memory. Emphasis is placed on why VR increases the ecological validity of memory research and the implications of such enhancements.

Validity and diagnostic performance of a virtual reality-based supermarket application "MEMOSHOP" for assessing episodic memory in normal and pathological aging

Objective

MEMOSHOP is a virtual reality (VR)-based supermarket application for assessing episodic memory in aging. The aim of this study was to examine its construct validity against the gold standard paper-and-pencil neuropsychological test for clinical memory assessment in mild cognitive impairment (MCI) in older adults.

Methods

Patients with isolated subjective cognitive complaints (SCCs) or MCI were recruited in the Bordeaux Memory Clinic (MEMENTO cohort). Cognitively normal elderly controls were also recruited. MEMOSHOP allows a near-ecological evaluation of episodic memory during a usual daily life activity, i.e. shopping at the supermarket. MEMOSHOP and the gold standard Free and Cued Selective Reminding Test (FCSRT: French adaptation) were administered to all participants to assess episodic memory. Non-parametric tests and receiver operating characteristic curves were computed to compare their performances.

Results

Twenty-nine patients (21 females, age = 71 years ±7) and 29 matched controls were evaluated. The performance trends observed with MEMOSHOP and FCSRT on free and cued recall were associated (p < .01) and comparable (p < .0001), without any participants' groups interaction. Although easier than FCSRT in free recall for participants, MEMOSHOP demonstrated better diagnostic performance based on cued recall in isolated SCCs/MCI patients (p < .05).

Conclusion

MEMOSHOP demonstrated its reliability and validity for VR-based episodic memory assessment in the early stage of MCI and is potentially of interest for use in memory clinic settings.

Virtual reality in the diagnostic and therapy for mental disorders: A systematic review

BACKGROUND

Virtual reality (VR) technologies are playing an increasingly important role in the diagnostics and treatment of mental disorders.

OBJECTIVE

To systematically review the current evidence regarding the use of VR in the diagnostics and treatment of mental disorders.

DATA SOURCE

Systematic literature searches via PubMed (last literature update: 9^th of May 2022) were conducted for the following areas of psychopathology: Specific phobias, panic disorder and agoraphobia, social anxiety disorder, generalized anxiety disorder, posttraumatic stress disorder (PTSD), obsessive-compulsive disorder, eating disorders, dementia disorders, attention-deficit/hyperactivity disorder, depression, autism spectrum disorder, schizophrenia spectrum disorders, and addiction disorders.

ELIGIBILITY CRITERIA

To be eligible, studies had to be published in English, to be peer-reviewed, to report original research data, to be VR-related, and to deal with one of the above-mentioned areas of psychopathology.

STUDY EVALUATION

For each study included, various study characteristics (including interventions and conditions, comparators, major outcomes and study designs) were retrieved and a risk of bias score was calculated based on predefined study quality criteria.

RESULTS

Across all areas of psychopathology, k = 9315 studies were inspected, of which k = 721 studies met the eligibility criteria. From these studies, 43.97% were considered assessment-related, 55.48% therapy-related, and 0.55% were mixed. The highest research activity was found for VR exposure therapy in anxiety disorders, PTSD and addiction disorders, where the most convincing evidence was found, as well as for cognitive trainings in dementia and social skill trainings in autism spectrum disorder.

CONCLUSION

While VR exposure therapy will likely find its way successively into regular patient care, there are also many other promising approaches, but most are not yet mature enough for clinical application.

REVIEW REGISTRATION

PROSPERO register CRD42020188436.

FUNDING

The review was funded by budgets from the University of Bonn. No third party funding was involved.

Application of virtual reality for dementia management

Age is recognized as the major factors of dementia, especially in for Alzheimer’s disease (AD). Given to the aged population, the increased number of demented population has been receiving a great impact in our society. Unfortunately, so far, no cured medicines have been demonstrated to provide effective treatment in AD. The combination of pharmacological and non-pharmacological interventions has been proposed to manage dementia with potential benefits especially in decreasing caregiver’s burden and behavior, as well as psychological problems of demented patients. Recently, giving to the glorious development in digital technologies, the virtual reality, one of the non-pharmacological interventions has been used extensively in dementia managements for its strengths which can be adapted in accordance with the heterogeneous needs from demented patients and their caregivers. However, various study designs and other reasons made these results difficult to be interpreted. In this review our goal is to provide a better understanding for these points.

The challenge of neuropsychological assessment of visual/visuo-spatial memory: A critical, historical review, and lessons for the present and future

A proliferation of tests exists for the assessment of auditory-verbal memory processes. However, from a clinical practice perspective, the situation is less clear when it comes to the ready availability of reliable and valid tests for the evaluation of visual/visuo-spatial memory processes. While, at face value, there appear to be a wide range of available tests of visual/visuo-spatial memory, utilizing different types of materials and assessment strategies, a number of criticisms have been, and arguably should be, leveled at the majority of these tests. The criticisms that have been directed toward what are typically considered to be visual/visuo-spatial memory tests, such as (1) the potential for verbal mediation, (2) over-abstraction of stimuli, (3) the requirement of a drawing response, and (4) the lack of sensitivity to unilateral brain lesions, mean that, in reality, the number of readily available valid tests of visual/visuo-spatial memory is, at best, limited. This article offers a critical, historical review on the existing measures and resources for the neuropsychological assessment of visual/visuo-spatial memory, and it showcases some examples of newer tests that have aimed to overcome the challenges of assessing these important aspects of memory. The article also identifies new trends and examples of how technological advances such as virtual reality may add value to overcome previous obstacles to assessment, thereby offering professionals more reliable, accurate means to evaluate visual/visuo-spatial memory in clinical practice.

Can the Virtual Reality-Based Spatial Memory Test Better Discriminate Mild Cognitive Impairment than Neuropsychological Assessment?

Neuropsychological screening tools for mild cognitive impairment (MCI) have been widely used. However, to date, their sensitivity and specificity still remain unsatisfied. This study aims to investigate whether spatial memory can discriminate MCI better than neuropsychological screening tools. A total of 56 healthy older adults and 36 older adults with MCI participated in this study; they performed a spatial cognitive task based on virtual reality (SCT-VR), the Korean version of the Montreal Cognitive Assessment (MoCA-K), and the Wechsler Adult Intelligence Scale-Revised Block Design Test (WAIS-BDT). The discriminant power was compared between the SCT-VR and the MoCA-K, and the reliability and validity of the SCT-VR were analyzed. The spatial memory, assessed by the SCT-VR, showed better sensitivity and specificity (sensitivity: 0.944; specificity: 0.964) than the MoCA-K (sensitivity: 0.857; specificity: 0.746). The test-retest reliability of the SCT-VR was relatively high (ICCs: 0.982, p < 0.001) and the concurrent validity of the SCT-VR with the MoCA-K (r = −0.587, p < 0.001) and the WAIS-BDT (r = −0.594, p < 0.001) was statistically significant. These findings shed light on the importance of spatial memory as a behavioral marker of MCI. The ecologically validated spatial memory tasks based on VR need to be investigated by neuroscientific studies in the future.

Older Adults Get Lost in Virtual Reality: Visuospatial Disorder Detection in Dementia Using a Voting Approach Based on Machine Learning Algorithms

As the age of an individual progresses, they are prone to more diseases; dementia is one of these age-related diseases. Regarding the detection of dementia, traditional cognitive testing is currently one of the most accurate tests. Nevertheless, it has many disadvantages, e.g., it does not measure the extent of the brain damage and does not take the patient’s intelligence into consideration. In addition, traditional assessment does not measure dementia under real-world conditions and in daily tasks. It is therefore advisable to investigate the newest, more powerful applications that combine cognitive techniques with computerized techniques. Virtual reality worlds are one example, and allow patients to immerse themselves in a controlled environment. This study created the Medical Visuospatial Dementia Test (referred to as the “MVD Test”) as a non-invasive, semi-immersive, and cognitive computerized test. It uses a 3D virtual environment platform based on medical tasks combined with AI algorithms. The objective is to evaluate two cognitive domains: visuospatial assessment and memory assessment. Using multiple machine learning algorithms (MLAs), based on different voting approaches, a 3D system classifies patients into three classes: patients with normal cognition, patients with mild cognitive impairment (MCI), and patients with severe cognitive impairment (dementia). The model with the highest performance was derived from voting approach named Ensemble Vote, where accuracy was 97.22%. Cross-validation accuracy of Extra Tree and Random Forest classifiers, which was greater than 99%, indicated a greater discriminate capacity than that of other classes.

Multisensory GPS impact on spatial representation in an immersive virtual reality driving game

Individuals are increasingly relying on GPS devices to orient and find their way in their environment and research has pointed to a negative impact of navigational systems on spatial memory. We used immersive virtual reality to examine whether an audio–visual navigational aid can counteract the negative impact of visual only or auditory only GPS systems. We also examined the effect of spatial representation preferences and abilities when using different GPS systems. Thirty-four participants completed an IVR driving game including 4 GPS conditions (No GPS; audio GPS; visual GPS; audio–visual GPS). After driving one of the routes in one of the 4 GPS conditions, participants were asked to drive to a target landmark they had previously encountered. The audio–visual GPS condition returned more accurate performance than the visual and no GPS condition. General orientation ability predicted the distance to the target landmark for the visual and the audio–visual GPS conditions, while landmark preference predicted performance in the audio GPS condition. Finally, the variability in end distance to the target landmark was significantly reduced in the audio–visual GPS condition when compared to the visual and audio GPS conditions. These findings support theories of spatial cognition and inform the optimisation of GPS designs.

Two Immersive Virtual Reality Tasks for the Assessment of Spatial Orientation in Older Adults with and Without Cognitive Impairment: Concurrent Validity, Group Comparison, and Accuracy Results

OBJECTIVE

Spatial disorientation is common in Alzheimer's disease (AD), Mild Cognitive Impairment (MCI), and preclinical individuals with AD biomarkers. However, traditional neuropsychological tests lack ecological validity for the assessment of spatial orientation and to date, there is still no gold standard. The current study aimed to determine the validity and accuracy of two virtual reality tasks for the assessment of spatial orientation.

METHODS

We adapted two spatial orientation tasks to immersive virtual environments: a "survey to route" task in which participants had to transfer information from a map to their body position within a maze [Spatial Orientation in Immersive Virtual Environment Test (SOIVET) Maze], and an allocentric-type, route learning task, with well-established topographic landmarks (SOIVET Route). A total of 19 MCI patients and 29 cognitively healthy older adults aged 61-92 participated in this study. Regular neuropsychological assessments were used for correlation analysis and participant performances were compared between groups. Receiver Operating Characteristic (ROC) curve analysis was performed for accuracy.

RESULTS

The SOIVET Maze correlated with measures of visuoperception, mental rotation, and planning, and was not related to age, educational level, or technology use profile. The SOIVET Route immediate correlated with measures of mental rotation, memory, and visuoconstruction, and was influenced only by education. Both tasks significantly differentiated MCI and control groups, and demonstrated moderate accuracy for the MCI diagnosis.

CONCLUSION

Traditional neuropsychological assessment presents limitations and immersive environments allow for the reproduction of complex cognitive processes. The two immersive virtual reality tasks are valid tools for the assessment of spatial orientation and should be considered for cognitive assessments of older adults.

A Virtual Navigation Training Promotes the Remapping of Space in Allocentric Coordinates: Evidence From Behavioral and Neuroimaging Data

Allocentric space representations demonstrated to be crucial to improve visuo-spatial skills, pivotal in every-day life activities and for the development and maintenance of other cognitive abilities, such as memory and reasoning. Here, we present a series of three different experiments: Experiment 1, Discovery sample (23 young male participants); Experiment 2, Neuroimaging and replicating sample (23 young male participants); and Experiment 3 (14 young male participants). In the experiments, we investigated whether virtual navigation stimulates the ability to form spatial allocentric representations. With this aim, we used a novel 3D videogame (MindTheCity!), focused on the navigation of a virtual town. We verified whether playing at MindTheCity! enhanced the performance on spatial representational tasks (pointing to a specific location in space) and on a spatial memory test (asking participant to remember the location of specific objects). Furthermore, to uncover the neural mechanisms underlying the observed effects, we performed a preliminary fMRI investigation before and after the training with MindTheCity!. Results show that our virtual training enhances the ability to form allocentric representations and spatial memory (Experiment 1). Experiments 2 and 3 confirmed the behavioral results of Experiment 1. Furthermore, our preliminary neuroimaging and behavioral results suggest that the training activates brain circuits involved in higher-order mechanisms of information encoding, triggering the activation of broader cognitive processes and reducing the working load on memory circuits (Experiments 2 and 3).

Application of Real and Virtual Radial Arm Maze Task in Human

Virtual Reality (VR) emerges as a promising technology capable of creating different scenarios in which the body, environment, and brain are closely related, proving enhancements in the diagnosis and treatment of several spatial memory deficits. In recent years, human spatial navigation has increasingly been studied in interactive virtual environments. However, navigational tasks are still not completely adapted in immersive 3D VR systems. We stipulate that an immersive Radial Arm Maze (RAM) is an excellent instrument, allowing the participants to be physically active within the maze exactly as in the walking RAM version in reality modality. RAM is a behavioral ecological task that allows the analyses of different facets of spatial memory, distinguishing declarative components from procedural ones. In addition to describing the characteristics of RAM, we will also analyze studies in which RAM has been used in virtual modality to provide suggestions into RAM building in immersive modality.

Virtual Reality Technology in Cognitive Rehabilitation Application: A Bibliometric Analysis (Preprint)

Background

In recent years, with the development of computer science and medical science, virtual reality (VR) technology has become a promising tool for improving cognitive function. Research on VR-based cognitive training has garnered increasing attention.

Objective

This study aimed to investigate the application status, research hot spots, and emerging trends of VR in cognitive rehabilitation over the past 20 years.

Methods

Articles on VR-based cognitive rehabilitation from 2001 to 2021 were retrieved from the Web of Science Core Collection. CiteSpace software was used for the visual analysis of authors and countries or regions, and Scimago Graphica software was used for the geographic visualization of published countries or regions. Keywords were clustered using the gCLUTO software.

Results

A total of 1259 papers were included. In recent years, research on the application of VR in cognitive rehabilitation has been widely conducted, and the annual publication of relevant literature has shown a positive trend. The main research areas include neuroscience and neurology, psychology, computer science, and rehabilitation. The United States ranked first with 328 papers, and Italy ranked second with 140 papers. Giuseppe Riva, an Italian academic, was the most prolific author with 29 publications. The most frequently cited reference was “Using Reality to Characterize Episodic Memory Profiles in Amnestic Mild Cognitive Impairment and Alzheimer’s Disease: Influence of Active and Passive Encoding.” The most common keywords used by researchers include “virtual reality,” “cognition,” “rehabilitation,” “performance,” and “older adult.” The largest source of research funding is from the public sector in the United States.

Conclusions

The bibliometric analysis provided an overview of the application of VR in cognitive rehabilitation. VR-based cognitive rehabilitation can be integrated into multiple disciplines. We conclude that, in the context of the COVID-19 pandemic, the development of VR-based telerehabilitation is crucial, and there are still many problems that need to be addressed, such as the lack of consensus on treatment methods and the existence of safety hazards.

Does the virtual shopping training improve executive function and instrumental activities of daily living of patients with mild cognitive impairment?

To date, ecological validity of virtual shopping training for patients with mild cognitive impairment (MCI) has not been confirmed yet. Main objective of this study was to investigate effects of virtual shopping training on executive function and instrumental activities of daily living (IADL) in patients with MCI. 32 patients with MCI were randomly assigned to the experimental group that received virtual shopping training or the waitlist control group for a total of 16 sessions. To examine effects of virtual shopping training on executive function and IADL, Korean version of the Executive Function Performance Test (EFPT-K) and Korean Instrumental Activities of Daily living (K-IADL) were conducted. After the 16 sessions, the experimental group showed greater improvement in the EFPT-K (p < 0.001) and the K-IADL (p < 0.001) compared to the control group. These results suggest that virtual shopping training might be clinically beneficial to enhance executive function and IADL in patients with MCI.

Virtual reality and mental health in older adults: a systematic review

IMPORTANCE

Virtual reality (VR) is a promising tool with the potential to enhance care of cognitive and affective disorders in the aging population. VR has been implemented in clinical settings with adolescents and children; however, it has been less studied in the geriatric population.

OBJECTIVE

The objective of this study is to determine the existing levels of evidence for VR use in clinical settings and identify areas where more evidence may guide translation of existing VR interventions for older adults.

DESIGN AND MEASUREMENTS

We conducted a systematic review in PubMed and Web of Science in November 2019 for peer-reviewed journal articles on VR technology and its applications in older adults. We reviewed article content and extracted the number of study participants, study population, goal of the investigation, the level of evidence, and categorized articles based on the indication of the VR technology and the study population.

RESULTS

The database search yielded 1554 total results, and 55 articles were included in the final synthesis. The most represented study design was cross-sectional, and the most common study population was subjects with cognitive impairment. Articles fell into three categories for VR Indication: Testing, Training, and Screening. There was a wide variety of VR environments used across studies.

CONCLUSIONS

Existing evidence offers support for VR as a screening and training tool for cognitive impairment in older adults. VR-based tasks demonstrated validity comparable to some paper-based assessments of cognition, though more work is needed to refine diagnostic specificity. The variety of VR environments used shows a need for standardization before comparisons can be made across VR simulations. Future studies should address key issues such as usability, data privacy, and confidentiality. Since most literature was generated from high-income countries (HICs), it remains unclear how this may be translated to other parts of the world.

Effects of virtual reality-based spatial cognitive training on hippocampal function of older adults with mild cognitive impairment

BACKGROUND

To date, there is a controversy on effects of cognitive intervention to maintain or improve hippocampal function for older adults with mild cognitive impairment (MCI).

OBJECTIVE

The main objective of this study was to exam effects of virtual reality-based spatial cognitive training (VR-SCT) using VR on hippocampal function of older adults with MCI.

METHOD

Fifty-six older adults with MCI were randomly allocated to the experimental group (EG) that received the VR-SCT or the waitlist control group (CG) for a total of 24 sessions. To investigate effects of the VR-SCT on spatial cognition and episodic memory, the Weschsler Adult Intelligence Scale-Revised Block Design Test (WAIS-BDT) and the Seoul Verbal Learning Test (SVLT) were used.

RESULTS

During the sessions, the training performances gradually increased (p < .001). After the intervention, the EG showed significant greater improvements in the WAIS-BDT (p < .001, η2 = .667) and recall of the SVLT (p < .05, η2 =.094) compared to the CG but in recognition of the SVLT (p > .05, η2 =.001).

CONCLUSION

These results suggest that the VR-SCT might be clinically beneficial to enhance spatial cognition and episodic memory of older adults with MCI.

Virtual reality-based monitoring test for MCI: A multicenter feasibility study

OBJECTIVES

As the significance of the early diagnosis of mild cognitive impairment (MCI) has emerged, it is necessary to develop corresponding screening tools with high ecological validity and feasible biomarkers. Virtual reality (VR)-based cognitive assessment program, which is close to the daily life of the older adults, can be suitable screening tools for MCI with ecological validity and accessibility. Meanwhile, dehydroepiandrosterone (DHEA) has been observed at a low concentration in the older adults with dementia or cognitive decline, indicating its potential as a biomarker of MCI. This study aimed to determine the efficacy and usability of a VR cognitive assessment program and salivary DHEA for screening MCI.

METHODS

The VR cognitive assessment program and the traditional Montreal Cognitive Assessment (MOCA) test were performed on 12 patients with MCI and 108 healthy older adults. The VR program operates in a situation of caring for a grandchild, and evaluates the memory, attention, visuospatial, and executive functions. An analysis of covariance (ANCOVA), a partial correlation analysis, and receiving operating characteristic (ROC) curve analysis were conducted for statistical analysis.

RESULTS

According to the ANCOVA, no significant difference in MOCA scores was found between the normal and MCI groups (F = 2.36, p = 0.127). However, the VR total score of the MCI group was significantly lower than that of the normal group (F = 8.674, p = 0.004). There was a significant correlation between the MOCA and VR scores in the total and matched subdomain scores. The ROC curve analysis also showed a larger area under the curve (AUC) for the VR test (0.765) than for the MOCA test (0.598), and the sensitivity and specificity of the VR program were 0.833 and 0.722, respectively. Salivary DHEA was correlated with VR total (R ² = 0.082, p = 0.01) and attention scores (R ² = 0.086, p = 0.009).

CONCLUSION

The VR cognitive test was as effective as the traditional MOCA test in the MCI classification and safe enough for older adults to perform, indicating its potential as a diagnostic tool. It has also been shown that salivary DHEA can be used as a biomarker for MCI.

Study of virtual reality for mild cognitive impairment: A bibliometric analysis using CiteSpace

Objectives

Non-invasive and low-cost virtual reality (VR) technology is important for early evaluation and intervention in mild cognitive impairment (MCI). This study aimed to demonstrate the current status of overseas and domestic research as well as the focus and frontier of VR technology among individuals with MCI through a bibliometric analysis.

Methods

Studies from the core collection of Web of Science™ between 1995 and 2020 were used; furthermore, CiteSpace 5.7 R3 was utilized to analyse information on authors/cited authors, keywords, burst words, and cited references.

Results

In total, 230 publications were identified. Most studies were published in the USA (45 publications) and Italy (41 publications), where Guiseppe Riva ranks first (14 publications), and Tarnanas I is the author with the highest centrality (0.44). The hot topics in VR applications in the MCI population are ‘physical activity,’ ‘people,’ ‘single-blind,’ ‘disease,’ ‘walking,’ ‘technology,’ ‘working memory,’ and ‘risk’ in recent years. The keyword ‘mild cognitive impairment’ has attracted extensive attention since 2012, showing the strongest citation outbreak (8.28). The clustering results of the literature show the research types and emerging trends, including ‘exergame,’ ‘serious games,’ ‘spatial navigation,’ ‘activities of daily living,’ ‘exercise,’ ‘enriched environment’ and ‘wayfinding.‘

Conclusions

Cognitive assessment and nonpharmacological intervention research on patients with MCI have become the focus of dementia prevention in recent years. Virtual technology, combined with traditional methods such as exercise therapy, provides new ideas for innovative cognitive evaluation and cognitive intervention.

In search of a naturalistic neuroimaging approach: Exploration of general feasibility through the case of VR-fMRI and application in the domain of episodic memory

Virtual Reality (VR) is an increasingly widespread tool for research as it allows the creation of experiments taking place in multimodal and daily-life-like environments, while keeping a strong experimental control. Adding neuroimaging to VR leads to a better understanding of the underlying brain networks activated during a naturalistic task, whether for research purposes or rehabilitation. The present paper focuses on the specific use of concurrent VR and fMRI and its technical challenges and feasibility, with a brief examination of the general existing solutions. Following the PRISMA guidelines, the review investigates the particular case of how VR-fMRI has explored episodic memory so far, with a comparison of object- and place-based episodic memory. This review confirms the involvement of cerebral regions well-known to be implicated in episodic memory and unravels other regions devoted to bodily and narrative aspects of the self, promoting new avenues of research in the domain of naturalistic episodic memory. Future studies should develop more immersive and interactive virtual neuroimaging features to increase ecological and embodied neurocognition aspects.

How rich are false memories in a naturalistic context in healthy aging?

The recall of factual and contextual information is a core characteristic of episodic memory sensitive to aging effects. The innovative aim of the present study was to assess in a naturalistic context the quantity and quality of correct and false free recalls among younger and older adults considering feature binding (What-Where-When-Details) and recollection (Remembering vs. Knowing). Thanks to virtual reality, we designed a multimodal environment simulating a lively town in which we implemented a variant of a DRM task rich in sets of semantically related items (e.g., fruits on a market stall). We asked 30 young and 30 older participants to navigate in the virtual environment, paying attention to the items, and then recall as many items and as much contextual information as possible and indicate the presence of recollection. As expected, older adults produced fewer correct recall but more intrusions than younger adults, and their correct recall was more deficient in binding and recollection. In both age groups, false recall was associated with the correct context inferred from a related set of items. However, the intrusions produced by older adults were highly recollected compared to those of the younger adults, and they were associated with false item-related contextual information.

The role of semantic memory in prospective memory and episodic future thinking: new insights from a case of semantic dementia

Prospective memory (PM), the ability to remember to execute planned actions, and episodic future thinking (EFT), the ability to imagine future personal events, are two core aspects of future-oriented cognition. The present study aimed for the first time at examining the role of semantic memory loss in PM and EFT in a single case patient (SL) at the early stage of semantic dementia.First, we investigated various types of PM as well as episodic memory of new events using a validated ecological assessment via virtual reality. Second, we examined EFT using a temporally extended version of the TEMPau task, which measures episodic aspects of remembering the past and imagining the future taking temporal distance into account.Patient SL was deficient in semantically linked event-based PM and was unable to provide any EFT for the most distant period but was preserved in other types of PM and near and intermediate EFT.These findings provide new evidence on the role of semantic memory in PM depending on the type of intention and in EFT depending on the temporal distance mirroring autobiographical memory. Finally, they point out a specific link between PM and near EFT in future-oriented cognition.

Building Embodied Spaces for Spatial Memory Neurorehabilitation with Virtual Reality in Normal and Pathological Aging

Along with deficits in spatial cognition, a decline in body-related information is observed in aging and is thought to contribute to impairments in navigation, memory, and space perception. According to the embodied cognition theories, bodily and environmental information play a crucial role in defining cognitive representations. Thanks to the possibility to involve body-related information, manipulate environmental stimuli, and add multisensory cues, virtual reality is one of the best candidates for spatial memory rehabilitation in aging for its embodied potential. However, current virtual neurorehabilitation solutions for aging and neurodegenerative diseases are in their infancy. Here, we discuss three concepts that could be used to improve embodied representations of the space with virtual reality. The virtual bodily representation is the combination of idiothetic information involved during virtual navigation thanks to input/output devices; the spatial affordances are environmental or symbolic elements used by the individual to act in the virtual environment; finally, the virtual enactment effect is the enhancement on spatial memory provided by actively (cognitively and/or bodily) interacting with the virtual space and its elements. Theoretical and empirical findings will be presented to propose innovative rehabilitative solutions in aging for spatial memory and navigation.

Test-retest reliability and practice effects of the virtual environment grocery store (VEGS)

INTRODUCTION

The use of virtual reality (VR) technology has been suggested as a method to increase ecological validity in neuropsychological assessments. Although validity has been a focus in VR research, little attention has been paid to other psychometric properties such as test-retest reliability and practice effects. Practice effects are common on traditional neuropsychological tests and can be impacted by novelty. Because VR is not widely used it was expected that participants would demonstrate higher practice effects on VR as compared to paper-and-pencil testing.

METHOD

To compare test-retest reliability and practice effects in VR and traditional paper-and-pencil testing, the Virtual Environment Grocery Store (VEGS) and California Verbal Learning Test - Second Edition (CVLT-II) were used in healthy adults (n = 44). Participants received follow-up testing approximately 2 weeks after the initial visit.

RESULTS

Significant practice effects of similar magnitude were seen on memory scores (i.e., total learning, long-delay free recall, and long-delay cued recall) on the VEGS and the CVLT-II. The VEGS and CVLT-II memory scores also demonstrated strong test-retest reliability (r's > .71). Lastly, total learning scores (d = .32) and long-delay cued recall (d = .70) scores were significantly higher on the CVLT-II compared to the VEGS (p's < .01).

CONCLUSIONS

Results suggested similar test-retest reliability and practice effects of the VEGS and CVLT-II, although the VEGS has the benefit of being an immersive technology that simulates an everyday activity. The study replicated past findings that the VEGS is more difficult than the CVLT-II which may be a useful property for clinical assessment.

Improving autobiographical memory in Alzheimer's disease by transcranial alternating current stimulation

We review the latest evidence from animal models, studies in humans using electrophysiology, experimental memory paradigms, and non-invasive brain stimulation (NIBS), in the form of transcranial alternating current stimulation (tACS), suggesting that the altered activity in networks that contribute to the autobiographical memory (ABM) deficits may be modifiable. ABM involves a specific brain network of interacting regions that store and retrieve life experiences. Deficits in ABM are early symptoms in patients with Alzheimer's disease (AD), and serve as relevant predictors of disease progression. The possibility to modify the neural substrates of ABM opens exciting avenues for the development of therapeutic approaches. Beyond a summary of the causal role of brain oscillations in ABM, we propose a new approach of modulating brain oscillations using personalized tACS with the possibility of reducing ABM deficits. We suggest that human experimental studies using cognitive tasks, EEG, and tACS can have future translational clinical implications.

Smart Health System to Detect Dementia Disorders Using Virtual Reality

Smart health technology includes physical sensors, intelligent sensors, and output advice to help monitor patients’ health and adjust their behavior. Virtual reality (VR) plays an increasingly larger role to improve health outcomes, being used in a variety of medical specialties including robotic surgery, diagnosis of some difficult diseases, and virtual reality pain distraction for severe burn patients. Smart VR health technology acts as a decision support system in the diseases diagnostic test of patients as they perform real world tasks in virtual reality (e.g., navigation). In this study, a non-invasive, cognitive computerized test based on 3D virtual environments for detecting the main symptoms of dementia (memory loss, visuospatial defects, and spatial navigation) is proposed. In a recent study, the system was tested on 115 real patients of which thirty had a dementia, sixty-five were cognitively healthy, and twenty had a mild cognitive impairment (MCI). The performance of the VR system was compared with Mini-Cog test, where the latter is used to measure cognitive impaired patients in the traditional diagnosis system at the clinic. It was observed that visuospatial and memory recall scores in both clinical diagnosis and VR system of dementia patients were less than those of MCI patients, and the scores of MCI patients were less than those of the control group. Furthermore, there is a perfect agreement between the standard methods in functional evaluation and navigational ability in our system where P-value in weighted Kappa statistic= 100% and between Mini-Cog-clinical diagnosis vs. VR scores where P-value in weighted Kappa statistic= 93%.

Sex Differences in Spatial Memory: Comparison of Three Tasks Using the Same Virtual Context

Spatial memory has been studied through different instruments and tools with different modalities of administration. The cognitive load varies depending on the measure used and it should be taken into account to correctly interpret results. The aim of this research was to analyze how men and women perform three different spatial memory tasks with the same spatial context but with different cognitive demands. A total of 287 undergraduate students from the University of Almeria (Spain) and the University of L'Aquila (Italy) participated in the study. They were divided into three groups balanced by sex according to the spatial memory test they performed: the Walking Space Boxes Room Task (WSBRT), the Almeria Spatial Memory Recognition Test (ASMRT) and the Non-Walking Space Boxes Room Task (NWSBRT). Time spent and number of errors/correct answers were registered for analysis. In relation to the WSBRT and the ASMRT, men were faster and reached the optimal level of performance before women. In the three tests, familiarity with the spatial context helped to reduce the number of errors, regardless of the level of difficulty. In conclusion, sex differences were determined by the familiarity with the spatial context, the difficulty level of the task, the active or passive role of the participant and the amount of visual information provided in each screen shot.

Differentiating Real-World Autobiographical Experiences without Recourse to Behaviour

Investigating human consciousness based on brain activity alone is a key challenge in cognitive neuroscience. One of its central facets, the ability to form autobiographical memories, has been investigated through several fMRI studies that have revealed a pattern of activity across a network of frontal, parietal, and medial temporal lobe regions when participants view personal photographs, as opposed to when they view photographs from someone else's life. Here, our goal was to attempt to decode when participants were re-experiencing an entire event, captured on video from a first-person perspective, relative to a very similar event experienced by someone else. Participants were asked to sit passively in a wheelchair while a researcher pushed them around a local mall. A small wearable camera was mounted on each participant, in order to capture autobiographical videos of the visit from a first-person perspective. One week later, participants were scanned while they passively viewed different categories of videos; some were autobiographical, while others were not. A machine-learning model was able to successfully classify the video categories above chance, both within and across participants, suggesting that there is a shared mechanism differentiating autobiographical experiences from non-autobiographical ones. Moreover, the classifier brain maps revealed that the fronto-parietal network, mid-temporal regions and extrastriate cortex were critical for differentiating between autobiographical and non-autobiographical memories. We argue that this novel paradigm captures the true nature of autobiographical memories, and is well suited to patients (e.g., with brain injuries) who may be unable to respond reliably to traditional experimental stimuli.

The Smart Aging Platform for Assessing Early Phases of Cognitive Impairment in Patients With Neurodegenerative Diseases

Background: Smart Aging is a serious game (SG) platform that generates a 3D virtual reality environment in which users perform a set of screening tasks designed to allow evaluation of global cognition. Each task replicates activities of daily living performed in a familiar environment. The main goal of the present study was to ascertain whether Smart Aging could differentiate between different types and levels of cognitive impairment in patients with neurodegenerative disease.

Methods: Ninety-one subjects (mean age = 70.29 ± 7.70 years)—healthy older adults (HCs, n = 23), patients with single-domain amnesic mild cognitive impairment (aMCI, n = 23), patients with single-domain executive Parkinson's disease MCI (PD-MCI, n = 20), and patients with mild Alzheimer's disease (mild AD, n = 25)—were enrolled in the study. All participants underwent cognitive evaluations performed using both traditional neuropsychological assessment tools, including the Mini-Mental State Examination (MMSE), Montreal Overall Cognitive Assessment (MoCA), and the Smart Aging platform. We analyzed global scores on Smart Aging indices (i.e., accuracy, time, distance) as well as the Smart Aging total score, looking for differences between the four groups.

Results: The findings revealed significant between-group differences in all the Smart Aging indices: accuracy (p < 0.001), time (p < 0.001), distance (p < 0.001), and total Smart Aging score (p < 0.001). The HCs outperformed the mild AD, aMCI, and PD-MCI patients in terms of accuracy, time, distance, and Smart Aging total score. In addition, the mild AD group was outperformed both by the HCs and by the aMCI and PD-MCI patients on accuracy and distance. No significant differences were found between aMCI and PD-MCI patients. Finally, the Smart Aging scores significantly correlated with the results of the neuropsychological assessments used.

Conclusion: These findings, although preliminary due to the small sample size, suggest the validity of Smart Aging as a screening tool for the detection of cognitive impairment in patients with neurodegenerative diseases.

The production of false recognition and the associated state of consciousness following encoding in a naturalistic context in aging

Using virtual reality, we implemented a naturalistic variant of the DRM paradigm in young and older adults to evaluate false recall and false recognition. We distinguished false recognition related to the highest semantic association (the critical lures), semantic similarity (i.e. items that belong to the same semantic category), and perceptual similarity (i.e. items that are similar, but not identical in terms of shape or color). The data revealed that younger adults recalled and recognized more correct elements than older adults did while the older adults intruded more critical items than younger adults. Both age groups produced false recognition related to the critical items, followed by perceptually and then semantically related items. False recognitions were highly recollective as they were mainly associated with a sense of remembering, even more so in older adults than in young adults. The decline of executive functions and working memory predicted age-related increases in false memories.

The Role of Virtual Reality in Screening, Diagnosing, and Rehabilitating Spatial Memory Deficits

Impairment of spatial memory, including an inability to recall previous locations and navigate the world, is often one of the first signs of functional disability on the road to cognitive impairment. While there are many screening and diagnostic tools which attempt to measure spatial memory ability, they are often not representative of real-life situations and can therefore lack applicability. One potential solution to this problem involves the use of virtual reality (VR), which immerses individuals in a virtually-simulated environment, allowing for scenarios more representative of real-life without any of the associated risks. Here, we review the evidence surrounding the use of VR for the screening and diagnosis of spatial memory impairments, including potential limitations and how it compares to standard neuropsychological tests. We will also discuss the evidence regarding the potential use of VR in the rehabilitation of spatial memory deficits, which has not been well studied, but which could be game-changing if proven successful.

Ego- and allo-network disconnection underlying spatial disorientation in subjective cognitive decline

Patients with Alzheimer's disease (AD) related dementia and mild cognitive impairment experience difficulties with spatial navigation (SN). However, SN has rarely been investigated in individuals with subjective cognitive decline (SCD), a preclinical stage with elevated progression rate to symptomatic AD. In this study, 30 SCD subjects and 30 controls underwent cognitive scale (CS) evaluation, a 2D computerized SN test, and resting-state functional magnetic resonance imaging scanning. Two SN brain networks (ego-network and allo-network), each with 10 selected spherical regions, were defined. We calculated the average network functional connectivity (FC) and region-to-region FC within the two networks and evaluated correlations with SN performance. Compared with the controls, the SCD group performed worse in the SN test and showed decreased FC between the right retrosplenial and right prefrontal cortices in the ego-network, and between the right retrosplenial cortex and right hippocampus in the allo-network. The logistic regression model based on SN and FC measures revealed a high area under the curve of .880 in differentiating SCD individuals from controls. These results suggest that SN network disconnection contributes to spatial deficits in SCD, and SN and FC measures could benefit the preclinical detection of subjects with incipient AD dementia.

The Fragility of Temporal Memory in Alzheimer's Disease

BACKGROUND

Although episodic memory impairment is one of the hallmarks of Alzheimer's disease (AD), the relative decline in the components of episodic memory (What, Where, and When) and the effects of cognitive training on each of them are still unknown.

OBJECTIVE

We aimed to independently assess the impairment in each component of episodic memory in early to moderate AD and address whether it can be enhanced through active, spatiotemporal episodic training.

METHODS

A non-verbal scene-based episodic memory task was developed to assess the ability to remember What, Where, and When information. Experiment 1 tested whether this task can differentiate AD subjects (N = 16) from healthy controls (N = 16). In Experiment 2, 13 AD subjects underwent 16 training sessions, followed by a re-administration of the scene-based memory task. Experiment 3 tested 42 healthy older adults and 51 younger adults on the same task to investigate the effects of normal aging.

RESULTS

Of the three components, When memory had the highest predictive power in distinguishing AD from normal aging. Following training of AD subjects, only Where memory improved. Only What memory revealed a significant decline in healthy subjects from 65-85 years of age.

CONCLUSION

These findings shed new light on the importance of the temporal component of episodic memory as a behavioral marker of AD. The selective improvement of spatial but not temporal memory through training further demonstrates the fragility of temporal memory even in early AD. Neuroscientific research is needed to distinguish whether the Where component was enhanced by improvements in hippocampal spatial representation or by other compensatory mechanisms.

Egocentric and Allocentric Spatial Memory in Mild Cognitive Impairment with Real-World and Virtual Navigation Tasks: A Systematic Review

BACKGROUND

Spatial navigation is the ability to estimate one's position on the basis of environmental and self-motion cues. Spatial memory is the cognitive substrate underlying navigation and relies on two different reference frames: egocentric and allocentric. These spatial frames are prone to decline with aging and impairment is even more pronounced in Alzheimer's disease (AD) or in mild cognitive impairment (MCI).

OBJECTIVE

To conduct a systematic review of experimental studies investigating which MCI population and tasks are used to evaluate spatial memory and how allocentric and egocentric deficits are impaired in MCI after navigation.

METHODS

PRISMA and PICO guidelines were applied to carry out the systematic search. Down and Black checklist was used to assess methodological quality.

RESULTS

Our results showed that amnestic MCI and AD pathology are the most investigated typologies; both egocentric and allocentric memory are impaired in MCI individuals, and MCI due to AD biomarkers has specific encoding and retrieval impairments; secondly, spatial navigation is principally investigated with the hidden goal task (virtual and real-world version), and among studies involving virtual reality, the privileged setting consists of non-immersive technology; thirdly, despite subtle differences, real-world and virtual versions showed good overlap for the assessment of MCI spatial memory.

CONCLUSION

Considering that MCI is a subclinical entity with potential risk for conversion to dementia, investigating spatial memory deficits with navigation tasks might be crucial to make accurate diagnosis and rehabilitation.

Using Posterior EEG Theta Band to Assess the Effects of Architectural Designs on Landmark Recognition in an Urban Setting

The process of urban landmark-based navigation has proven to be difficult to study in a rigorous fashion, primarily due to confounding variables and the problem of obtaining reliable data in real-world contexts. The development of high-resolution, immersive virtual reality technologies has opened exciting new possibilities for gathering data on human wayfinding that could not otherwise be readily obtained. We developed a research platform using a virtual environment and electroencephalography (EEG) to better understand the neural processes associated with landmark usage and recognition during urban navigation tasks. By adjusting the architectural parameters of different buildings in this virtual environment, we isolated and tested specific design features to determine whether or not they served as a target for landmarking. EEG theta band (4-7 Hz) event-related synchronization/desynchronization over posterior scalp areas was evaluated at the time when participants observed each target building along a predetermined self-paced route. A multi-level linear model was used to investigate the effects of salient architectural features on posterior scalp areas. Our results support the conclusion that highly salient architectural features-those that contrast sharply with the surrounding environment-are more likely to attract visual attention, remain in short-term memory, and activate brain regions associated with wayfinding compared with non-salient buildings. After establishing this main aggregate effect, we evaluated specific salient architectural features and neural correlates of navigation processing. The buildings that most strongly associated extended gaze time, location recall accuracy, and changes in theta-band neural patterns with landmarking in our study were those that incorporated rotational twist designs and natural elements such as trees and gardens. Other building features, such as unusual façade patterns or building heights, were to a lesser extent also associated with landmarking.