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.

Exploring the Remediation of Behavioral Disturbances of Spatial Cognition in Community-Dwelling Senior Citizens with Mild Cognitive Impairment via Innovative Technological Apparatus (BDSC-MCI Project): Protocol for a Prospective, Multi-Center Observational Study.

Spatial navigation (SN) has been reported to be one of the first cognitive domains to be affected in Alzheimer's disease (AD), which occurs as a result of progressive neuropathology involving specific brain areas. Moreover, the epsilon 4 isoform of apolipoprotein-E (APOE-ε4) has been associated with both sporadic and familial late-onset AD, and patients with mild cognitive impairment (MCI) due to AD are more likely to progressively deteriorate. Spatial navigation performance will be examined on a sample of 76 community-dwelling senior citizens (25 healthy controls; 25 individuals with subjective cognitive decline (SCD); and 26 patients with MCI due to AD) via a virtual computer-based task (i.e., the AppleGame) and a naturalistic task (i.e., the Detour Navigation Test-modified version) for which a wearable device with sensors will be used for recording gait data and revealing physiological parameters that may be associated with spatial disorientation. We expect that patients with MCI due to AD and APOE-ε4 carriers will show altered SN performances compared to individuals with SCD and healthy controls in the experimental tasks, and that VR testing may predict ecological performance. Impaired SN performances in people at increased risk of developing AD may inform future cognitive rehabilitation protocols for counteracting spatial disorientation that may occur during elders' traveling to unfamiliar locations. The research protocol has been approved by the Ethics Committee of the Istituto Auxologico Italiano. Findings will be published in peer-reviewed medical journals and discussed in national and international congresses.

The multisensory mind: a systematic review of multisensory integration processing in Anorexia and Bulimia Nervosa.

Individuals with Anorexia Nervosa and Bulimia Nervosa present alterations in the way they experience their bodies. Body experience results from a multisensory integration process in which information from different sensory domains and spatial reference frames is combined into a coherent percept. Given the critical role of the body in the onset and maintenance of both Anorexia Nervosa and Bulimia Nervosa, we conducted a systematic review to examine multisensory integration abilities of individuals affected by these two conditions and investigate whether they exhibit impairments in crossmodal integration. We searched for studies evaluating crossmodal integration in individuals with a current diagnosis of Anorexia Nervosa and Bulimia Nervosa as compared to healthy individuals from both behavioral and neurobiological perspectives. A search of PubMed, PsycINFO, and Web of Sciences databases was performed to extract relevant articles. Of the 2348 studies retrieved, 911 were unique articles. After the screening, 13 articles were included. Studies revealed multisensory integration abnormalities in patients affected by Anorexia Nervosa; only one included individuals with Bulimia Nervosa and observed less severe impairments compared to healthy controls. Overall, results seemed to support the presence of multisensory deficits in Anorexia Nervosa, especially when integrating interoceptive and exteroceptive information. We proposed the Predictive Coding framework for understanding our findings and suggested future lines of investigation.

Diagnoses of Anorexia Nervosa and Bulimia Nervosa have increased dramatically in recent years, taking on the characteristics of a mental health emergency. More research is therefore needed to better understand these conditions, especially given their complex and multifaceted nature. Patients affected by these conditions report significant alterations in body-self experience. Body experience results from a cross-modal integration process in which information from different sensory modalities and spatial frames is combined. Therefore, we systematically reviewed studies that focused on multisensory integration in patients affected by Anorexia Nervosa and Bulimia Nervosa, as it may play a key role in the onset and maintenance of these pathologies. Studies in this review found multisensory integration difficulties in patients with Anorexia Nervosa, but not enough studies were retrieved to draw conclusions regarding Bulimia Nervosa. We discussed findings trying to link behavioral, neuropsychological, and neuroscientific evidence in light of the predictive coding framework to provide a different perspective on patients' distorted body experiences. This may lead to new insights to refine our understanding of these complex and poorly understood disorders.

Ecological Meanings: A Consensus Paper on Individual Differences and Contextual Influences in Embodied Language.

Embodied theories of cognition consider many aspects of language and other cognitive domains as the result of sensory and motor processes. In this view, the appraisal and the use of concepts are based on mechanisms of simulation grounded on prior sensorimotor experiences. Even though these theories continue receiving attention and support, increasing evidence indicates the need to consider the flexible nature of the simulation process, and to accordingly refine embodied accounts. In this consensus paper, we discuss two potential sources of variability in experimental studies on embodiment of language: individual differences and context. Specifically, we show how factors contributing to individual differences may explain inconsistent findings in embodied language phenomena. These factors include sensorimotor or cultural experiences, imagery, context-related factors, and cognitive strategies. We also analyze the different contextual modulations, from single words to sentences and narratives, as well as the top-down and bottom-up influences. Similarly, we review recent efforts to include cultural and language diversity, aging, neurodegenerative diseases, and brain disorders, as well as bilingual evidence into the embodiment framework. We address the importance of considering individual differences and context in clinical studies to drive translational research more efficiently, and we indicate recommendations on how to correctly address these issues in future research. Systematically investigating individual differences and context may contribute to understanding the dynamic nature of simulation in language processes, refining embodied theories of cognition, and ultimately filling the gap between cognition in artificial experimental settings and cognition in the wild (i.e., in everyday life).

Correction: Technology-Assisted Cognitive Motor Dual-Task Rehabilitation in Chronic Age-Related Conditions: Systematic Review.

[This corrects the article DOI: 10.2196/44484.].

Prognostic relevance of gait-related cognitive functions for dementia conversion in amnestic mild cognitive impairment.

BACKGROUND: Increasing research suggests that gait abnormalities can be a risk factor for Alzheimer's Disease (AD). Notably, there is growing evidence highlighting this risk factor in individuals with amnestic Mild Cognitive Impairment (aMCI), however further studies are needed. The aim of this study is to analyze cognitive tests results and brain-related measures over time in aMCI and examine how the presence of gait abnormalities (neurological or orthopedic) or normal gait affects these trends. Additionally, we sought to assess the significance of gait and gait-related measures as prognostic indicators for the progression from aMCI to AD dementia, comparing those who converted to AD with those who remained with a stable aMCI diagnosis during the follow-up. METHODS: Four hundred two individuals with aMCI from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database were included. Robust linear mixed-effects models were used to study the impact of gait abnormalities on a comprehensive neuropsychological battery over 36 months while controlling for relevant medical variables at baseline. The impact of gait on brain measures was also investigated. Lastly, the Cox proportional-hazards model was used to explore the prognostic relevance of abnormal gait and neuropsychological associated tests. RESULTS: While controlling for relevant covariates, we found that gait abnormalities led to a greater decline over time in attention (DSST) and global cognition (MMSE). Intriguingly, psychomotor speed (TMT-A) and divided attention (TMT-B) declined uniquely in the abnormal gait group. Conversely, specific AD global cognition tests (ADAS-13) and auditory-verbal memory (RAVLT immediate recall) declined over time independently of gait profile. All the other cognitive tests were not significantly affected by time or by gait profile. In addition, we found that ventricles size increased faster in the abnormal gait group compared to the normal gait group. In terms of prognosis, abnormal gait (HR = 1.7), MMSE (HR = 1.09), and DSST (HR = 1.03) covariates showed a higher impact on AD dementia conversion. CONCLUSIONS: The importance of the link between gait and related cognitive functions in terms of diagnosis, prognosis, and rehabilitation in aMCI is critical. We showed that in aMCI gait abnormalities lead to executive functions/attention deterioration and conversion to AD dementia.

Technologies for frailty, comorbidity, and multimorbidity in older adults: a systematic review of research designs.

BACKGROUND: Frailty, neurodegeneration and geriatric syndromes cause a significant impact at the clinical, social, and economic level, mainly in the context of the aging world. Recently, Information and Communication Technologies (ICTs), virtual reality tools, and machine learning models have been increasingly applied to the care of older patients to improve diagnosis, prognosis, and interventions. However, so far, the methodological limitations of studies in this field have prevented to generalize data to real-word. This review systematically overviews the research designs used by studies applying technologies for the assessment and treatment of aging-related syndromes in older people. METHODS: Following the PRISMA guidelines, records from PubMed, EMBASE, and Web of Science were systematically screened to select original articles in which interventional or observational designs were used to study technologies' applications in samples of frail, comorbid, or multimorbid patients. RESULTS: Thirty-four articles met the inclusion criteria. Most of the studies used diagnostic accuracy designs to test assessment procedures or retrospective cohort designs to build predictive models. A minority were randomized or non-randomized interventional studies. Quality evaluation revealed a high risk of bias for observational studies, while a low risk of bias for interventional studies. CONCLUSIONS: The majority of the reviewed articles use an observational design mainly to study diagnostic procedures and suffer from a high risk of bias. The scarce presence of methodologically robust interventional studies may suggest that the field is in its infancy. Methodological considerations will be presented on how to standardize procedures and research quality in this field.

A predictive coding approach to psychedelic virtual-induced hallucinations and creative cognition in aging.

Recent research has investigated the potential of psychedelic substances in treating various neurological and psychiatric disorders. In particular, there has been a growth in studies concerning the intersection of psychedelics, Virtual Reality (VR), and Cognitive Flexibility (CF). Indeed, the use of immersive technology allows the simulation of the perceptual and cognitive effects of psychedelic substances without the potential risks associated with them. CF is strongly associated with creative cognition, a complex cognitive mechanism involved in creative thinking and associated with the prefrontal cortex and the neural networks supporting executive functions, memory, attention, and spontaneous modes of thought. The Bayesian brain approach, which is rooted in predictive coding, has emerged as a promising framework for understanding the effects of psychedelic hallucinations on cognitive functioning. Psychedelic substances may enhance creativity by inducing a state of CF, allowing for a wider range of associations and possibilities to be explored and increasing openness to experience. A decline in cognitive abilities, including creative processing and divergent thinking, is observed during the aging process. In particular, studies on Mild Cognitive Impairment (MCI) show poorer performance in executive functions, including CF. The present paper suggests that psychedelic hallucinations induced by VR may help optimize the balance between top-down expectations and bottom-up sensory information. Therefore, enhanced CF and creativity may be crucial during the aging process for maintaining cognitive functions and preventing pathological conditions.

Phonological similarity between words is represented in declarative memory as spatial distance.

Space can be used as a metaphor to describe semantic and perceptual similarity. Research has shown that similarity and spatial information can influence each other. On the one hand, similarity entails spatial closeness; on the other hand, proximity leads to similarity judgment. This spatial information can be stored in declarative memory and measured later on. However, it is unknown if phonological similarity/dissimilarity between words is represented as spatial closeness/distance in declarative memory. In this study, 61 young adults were tested on a remember-know (RK) spatial distance task. Participants learned noun pairs on the PC screen that were manipulated concerning their phonological similarity (similar vs. dissimilar) and reciprocal spatial distance (near vs. far). In the recognition phase, old-new, RK, and spatial distance judgments were asked. We found that for hit responses in both R and K judgments, phonologically similar word pairs were remembered closer compared to phonologically dissimilar pairs. This was also true for false alarms after K judgments. Lastly, the actual spatial distance at encoding was only retained for hit R responses. Results suggest that phonological similarity/dissimilarity is represented respectively with spatial closeness/distance and that this information is stored in the neurocognitive system of declarative memory.

The interaction between motor simulation and spatial perspective-taking in action language: a cross-cultural study.

Growing evidence has revealed the crucial role of motor simulation and spatial perspective-taking in action language. However, there is still a lack of understanding of how motor and spatial processes interact when there are multiple actors involved, and if embodied processes are consistent across different cultures. To address this gap, we examined the interaction between motor simulation and spatial perspective-taking in action-sentences comprehension, along with the consistency of embodied processes across cultures. We collected data from Italian and US English speakers using an online sentence-picture verification task. The participants completed four conditions: two congruent (i.e., the participant is the agent in the sentence and the photo; the agent is someone else interacting with the participant in both the sentence and the picture) and two incongruent (i.e., the agents of the sentence and the picture do not match). The results show that when the perspective of the picture matched that described in the sentence-processing reaction times (RTs) were faster than in the incongruent conditions. In the congruent conditions where the agent is someone else, RTs were slower compared to the condition where the participant is the agent. This has been interpreted as claiming that motor simulation and perspective-taking are independent processes interacting during sentence comprehension (e.g., motor simulation is always run in the role of the agent, but we can adopt multiple perspectives depending on the pronouns and the contextual cues). Furthermore, Bayesian analysis provided evidence that embodied processing of action language entwines a common mechanism, suggesting cross-cultural consistency of embodied processes.

Technology-Assisted Cognitive Motor Dual-Task Rehabilitation in Chronic Age-Related Conditions: Systematic Review.

BACKGROUND: Cognitive-motor dual-task (CMDT) is defined as the parallel processing of motor (eg, gait) and cognitive (eg, executive functions) activities and is an essential ability in daily life. Older adults living with frailty, chronic conditions (eg, neurodegenerative diseases), or multimorbidity pay high costs during CMDT. This can have serious consequences on the health and safety of older adults with chronic age-related conditions. However, CMDT rehabilitation can provide useful and effective therapies for these patients, particularly if delivered through technological devices. OBJECTIVE: This review aims to describe the current technological applications, CMDT rehabilitative procedures, target populations, condition assessment, and efficacy and effectiveness of technology-assisted CMDT rehabilitation in chronic age-related conditions. METHODS: We performed this systematic review, following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, on 3 databases (Web of Science, Embase, and PubMed). Original articles that were published in English; involved older adults (>65 years) with ≥1 chronic condition and/or frailty; and tested, with a clinical trial, a technology-assisted CMDT rehabilitation against a control condition were included. Risk of bias (Cochrane tool) and the RITES (Rating of Included Trials on the Efficacy-Effectiveness Spectrum) tool were used to evaluate the included studies. RESULTS: A total of 1097 papers were screened, and 8 (0.73%) studies met the predefined inclusion criteria for this review. The target conditions for technology-assisted CMDT rehabilitation included Parkinson disease and dementia. However, little information regarding multimorbidity, chronicity, or frailty status is available. The primary outcomes included falls, balance, gait parameters, dual-task performance, and executive functions and attention. CMDT technology mainly consists of a motion-tracking system combined with virtual reality. CMDT rehabilitation involves different types of tasks (eg, obstacle negotiation and CMDT exercises). Compared with control conditions, CMDT training was found to be pleasant, safe, and effective particularly for dual-task performances, falls, gait, and cognition, and the effects were maintained at midterm follow-up. CONCLUSIONS: Despite further research being mandatory, technology-assisted CMDT rehabilitation is a promising method to enhance motor-cognitive functions in older adults with chronic conditions.

A Self-Help Virtual Therapeutic Experience Intervention for Overcoming Psychological Distress Related to the COVID-19 Pandemic: Results From the European Multicentric COVID Feel Good Trial.

OBJECTIVE: The general objective of the current study was to investigate the efficacy of a novel self-help virtual therapeutic experience (specifically, the COVID Feel Good intervention) in lowering the psychological burden experienced during the COVID-19 lockdowns in four European countries. METHODS: We focused on participants recruited from June 2020 to May 2021 in the context of a European multicenter project including four university/academic sites. The total number of participants in the longitudinal studies was 107 (study 1, N = 40; study 2, N = 29; study 3, N = 38). The randomized controlled trial (study 4) included 31 participants in total, 16 in the intervention group and 15 in the control group. Primary outcome measures were depression, anxiety, stress symptoms, perceived stress level, and perceived hopelessness. The secondary outcome was experienced social connectedness. RESULTS: Using separate linear mixed-effects models, the most consistent result across countries was a reduction in perceived stress after the participation in the COVID Feel Good intervention. By pooling the results of the models using a random-effects meta-analysis, we found that after the COVID Feel Good intervention, participants reported a decrease in perceived general distress (mean standardized effect size for general distress in the treatment groups compared with the control conditions was -0.52 [ p = .008, 95% confidence interval = -0.89 to -0.14]) and an increase in the perceived social connection (mean standardized effect size for social connection using COVID Feel Good compared with the control conditions was 0.50 [ p ≤ .001, 95% confidence interval = 0.25 to 0.76]). CONCLUSIONS: Findings of this study indicate that a virtual self-help intervention is effective in reducing psychological distress. These results contribute to the growing literature supporting the use of digital psychological therapies to relieve psychological distress among the general population during the COVID-19 pandemic.Trial Registration : ISRCTN63887521.

Mental health meets computational neuroscience: A predictive Bayesian account of the relationship between interoception and multisensory bodily illusions in anorexia nervosa.

Mental health disorders pose a significant challenge to society. The Bayesian perspective on the mind offers unique insights and tools that may help address a variety of mental health conditions. Psychopathological dysfunctions are often connected to altered predictive and active inference processes, in which cognitive and physiological pathogenic beliefs shape the clinical condition and its symptoms. However, there is a lack of general empirical models that integrate cognitive beliefs, physiological experience, and symptoms in healthy and clinical populations. In this study, we examined the relationship between altered predictive mechanisms, interoception, and pathological bodily distortions in healty individuals and in individuals suffering from anorexia nervosa (AN). AN patients (N=15) completed a Virtual Reality Full-Body Illusion along with interoceptive tasks twice: at hospital admission during an acute symptomatological phase (Time 1) and after a 12-week outpatient clinical weight-restoring rehabilitative program (Time 2). Results were compared to a healthy control group. Our findings indicated that higher levels of interoceptive metacognitive awareness were associated with a greater embodiment. However, unlike in healthy participants, AN patients' interoceptive metacognition was linked to embodiment even in multisensory mismatching (asynchronous) conditions. In addition, unlike in healthy participants, higher interoceptive metacognition in AN patients was related to prior abnormal bodily distortions during the acute symptomatology phase. Prediction errors in bodily estimates predicted posterior bodily estimate distortions after the illusion, but while this relationship was only significant in the synchronous condition in healthy participants, there was no significant difference between synchronous and asynchronous conditions in AN patients. Despite the success of the rehabilitation program in restoring some dysfunctional patterns in the AN group, prediction errors and posterior estimate distortions were present at hospital discharge. Our findings suggest that individuals with AN prioritize interoceptive metacognitive processes (i.e., confidence in their own perceived sensations rather than their actual perceptions), disregarding bottom-up bodily inputs in favour of their prior altered top-down beliefs. Moreover, even if the rehabilitative program partially mitigated these alterations, the pathological condition impaired the patients' ability to coherently update their prior erroneous expectations with real-time multisensory bottom-up bodily information, possibly locking the patients in the experience of a distorted prior top-down belief. These results suggest new therapeutic perspectives and introduce the framework of regenerative virtual therapy (RVT), which aims at utilizing technology-based somatic modification techniques to restructure the maladaptive priors underlying a pathological condition.

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.

Effectiveness of a Virtual-Reality-Based Self-Help Intervention for Lowering the Psychological Burden during the COVID-19 Pandemic: Results from a Randomized Controlled Trial in Iran.

BACKGROUND: The COVID-19 pandemic. In this framework, digital self-help interventions have the potential to provide flexible and scalable solutions for delivering evidence-based treatments that do not necessitate face-to-face meetings. OBJECTIVE: as part of a multicentric project, the purpose of the current randomized controlled trial was to evaluate the efficacy of a Virtual-Reality-based self-help intervention (namely, COVID Feel Good) in lowering the psychological distress experienced during the COVID-19 pandemic in Iran. METHODS: 60 participants were randomly assigned to the experimental (COVID Feel Good intervention group) or the control (no-treatment control group) condition. At the beginning of the intervention (Day 0), at the end of the intervention (Day 7), and after a 2-week follow-up (Day 21), measurements of depressive and anxiety levels, general distress, perceived levels of stress, hopelessness (primary outcome measures), perceived interpersonal closeness with the social world, and fear of COVID-19 (secondary outcome measure) were collected. The protocol consists of two integrated parts: the first part includes a relaxing 10-min three-hundred-sixty-degree (360°) video, while the second one includes social tasks with specified objectives. RESULTS: In terms of the primary outcomes, participants in the COVID Feel Good intervention group improved in depression, stress, anxiety, and perceived stress but not hopelessness. Secondary outcome results showed an improvement in perceived social connectedness and a substantial decrease in fear of COVID-19. CONCLUSIONS: these findings on the efficacy of COVID Feel Good training add to the growing body of evidence demonstrating the feasibility of digital self-help interventions in promoting well-being during this unique period.

Enhancing spatial navigation skills in mild cognitive impairment patients: a usability study of a new version of ANTaging software.

Introduction: Mild Cognitive Impairment (MCI) often presents challenges related to spatial navigation and retention of spatial information. Navigating space involves intricate integration of bodily and environmental cues. Spatial memory is dependent on two distinct frame of reference systems for organizing this information: egocentric and allocentric frames of reference. Virtual Reality (VR) has emerged as a promising technology for enhancing spatial navigation skills and spatial memory by facilitating the manipulation of bodily, environmental, and cognitive cues. Methods: This usability study was based on a fully within-subjects design in which seven MCI patients underwent two kinds of VR conditions: participants were required to complete the ANTaging demo both in Oculus Rift S (immersive condition) and in Samsung UHD 4K monitor (semi-immersive condition). Participants were seated and they had to use a foot-motion pad to navigate and explore the environment to collect and relocate some objects in the virtual environment. Post-interaction, users provided feedback on their experiences. Additionally, usability, potential side effects, data analysis feasibility, and user preferences with immersive and semi-immersive technologies were assessed through questionnaires. Results: Results indicated higher usability ratings for the semi-immersive setup, with fewer negative effects reported compared to the immersive counterpart. According to qualitative analyses of the interviews, patients do seem to like both VR apparatuses even though the semi-immersive condition was perceived as the most suitable choice because of the size of the screen. Patients generally found it difficult to remember object locations. Participants expressed the need for more practice with the foot-motion pad, despite an overall positive experience. They generally would like to use this system to improve their memory. Discussion: Identifying these key aspects was crucial for refining the system before the upcoming clinical trial. This study sheds light on the potential of semi-immersive VR in aiding individuals with MCI, paving the way for enhanced spatial navigation interventions.

Predictive power of gait and gait-related cognitive measures in amnestic mild cognitive impairment: a machine learning analysis.

Introduction: Gait disorders and gait-related cognitive tests were recently linked to future Alzheimer's Disease (AD) dementia diagnosis in amnestic Mild Cognitive Impairment (aMCI). This study aimed to evaluate the predictive power of gait disorders and gait-related neuropsychological performances for future AD diagnosis in aMCI through machine learning (ML). Methods: A sample of 253 aMCI (stable, converter) individuals were included. We explored the predictive accuracy of four predictors (gait profile plus MMSE, DSST, and TMT-B) previously identified as critical for the conversion from aMCI to AD within a 36-month follow-up. Supervised ML algorithms (Support Vector Machine [SVM], Logistic Regression, and k-Nearest Neighbors) were trained on 70% of the dataset, and feature importance was evaluated for the best algorithm. Results: The SVM algorithm achieved the best performance. The optimized training set performance achieved an accuracy of 0.67 (sensitivity = 0.72; specificity = 0.60), improving to 0.70 on the test set (sensitivity = 0.79; specificity = 0.52). Feature importance revealed MMSE as the most important predictor in both training and testing, while gait type was important in the testing phase. Discussion: We created a predictive ML model that is capable of identifying aMCI at high risk of AD dementia within 36 months. Our ML model could be used to quickly identify individuals at higher risk of AD, facilitating secondary prevention (e.g., cognitive and/or physical training), and serving as screening for more expansive and invasive tests. Lastly, our results point toward theoretically and practically sound evidence of mind and body interaction in AD.