Efficacy and Moderators of Virtual Reality for Cognitive Training in People with Dementia and Mild Cognitive Impairment: A Systematic Review and Meta-Analysis

Background: Mild cognitive impairment (MCI) and dementia result in cognitive decline which can negatively impact everyday functional abilities and quality of life. Virtual reality (VR) interventions could benefit the cognitive abilities of people with MCI and dementia, but evidence is inconclusive. Objective: To investigate the efficacy of VR training on global and domain-specific cognition, activities of daily living and quality of life. To explore the influence of priori moderators (e.g., immersion type, training type) on the effects of VR training. Adverse effects of VR training were also considered. Methods: A systematic literature search was conducted on all major databases for randomized control trial studies. Two separate meta-analyses were performed on studies with people with MCI and dementia. Results: Sixteen studies with people with MCI and four studies with people with dementia were included in each meta-analysis. Results showed moderate to large effects of VR training on global cognition, attention, memory, and construction and motor performance in people with MCI. Immersion and training type were found to be significant moderators of the effect of VR training on global cognition. For people with dementia, results showed moderate to large improvements after VR training on global cognition, memory, and executive function, but a subgroup analysis was not possible. Conclusion: Our findings suggest that VR training is an effective treatment for both people with MCI and dementia. These results contribute to the establishment of practical guidelines for VR interventions for patients with cognitive decline

가상현실 내 정보 불일치를 활용한 인지기능 평가: 탐색적 고찰

학위논문(박사) -- 서울대학교대학원 : 인문대학 협동과정 인지과학전공, 2022.2. 이경민.본 박사논문의 목적은 가상현실 내에서 발생하는 정보불일치에 대해서 알아보고, 정보 불일치로 인한 인지적 반응을 인지기능 평가에 활용할 수 있는 방안을 고찰하고자 함이다. 가상현실 주방과제를 구현하여 과제 수행 중 나타나는 움직임과 인지작용의 특성을 알아보고자 하였다. 또한 VR에서 과제수행 시 나타나는 인지 부하의 요인을 탐색하였다. 특히, 감각운동 조절 측면에서 가상현실 내 발생하는 정보불일치로 인한 인지 과부하를 살펴보았다. 첫째, 가상현실과 실제환경에서 작동하는 인지과정이 어떻게 다른지 알아보기 위해 두 환경 간의 과제 수행 차이를 비교하였다. 젊은 성인 그룹에서는 어려운 주방과제 수행 시 가상현실과 실제환경 간의 수행시간에 유의한 차이가 있었지만 쉬운 주방 과제에서는 차이가 없었다. 반면 노인 집단에서는 과제의 난이도와 관계없이 두 환경 간의 수행 시간에 상당한 차이가 있었다. 노인의 경우 가상현실에서 감각운동 조절의 어려움을 보였다. 즉 노인의 경우 젊은 성인에 비해 가상현실 내에서의 감각운동 조절이 더 어렵기 때문에 이로 인한 인지적 부하가 과제 수행 자체의 인지적 부하에 가중되어 과제 난이도가 어려워지면 인지용량의 한계를 초과하게 된다. 둘째, 가상 주방과제 수행 시 인지기능이 저하됨에 따라 갑자기 휙 움직이는(jerky) 패턴을 보이는 것으로 나타났다. 이는 인지기능이 저하된 노인의 경우 환경에 대한 예측력이 저하되어 최소 저크운동 조절(minimal jerk movement control)에 어려움이 있음을 시사한다. 또한 인지기능이 높은 그룹보다 인지기능이 낮은 노인 그룹의 경우 과제가 완료될 때까지의 일련의 움직임 단계가 더 많았다. 인지기능이 저하됨에 따라 비효율적이고 분주한 움직임을 보인다고 할 수 있다. 또한 다중회귀분석 결과, 노인이 가상현실 주방과제를 효율적으로 수행함에 있어 연령 및 학력 보다는 인지기능이 가장 영향을 미치는 요인으로 나타났다. 즉 가상현실 기반 과제수행은 순수 인지기능만을 평가하는 새로운 대안으로 제시할 수 있다. 마지막으로 감각운동 피드백의 예측불가능성(unpredictability)이 가상현실에서 인지부하를 유발하는 방식을 알아보고자 하였다. 섭동의 예측 가능성에 따른 반응 시간과 이동 속도를 암묵적 5°와 명시적 15° 섭동 조건에서 각각 측정하였다. 그 결과 암묵적 운동 제어 시 섭동의 변화를 예측할 수 없을 때 움직임의 정확도를 높이기 위해 움직임이 느려지는 전략(accuracy and speed trade-off)을 사용하는 것으로 나타났다. 즉, 감각운동조절 과정 상에서 정보 불일치로 인한 예측 불가능성에 대해 우리의 뇌는 다른 인지전략을 취한다고 설명할 수 있다. 결론적으로 가상현실은 기술적 충실도(fidelity) 문제로 인해 감각 피드백이 예측 불가능하고 가변적이기 때문에 실제 환경보다 더 많은 인지 부하를 유발한다. 특히 가상현실에서의 감각운동 조절은 실제환경에서 인간의 운동 시스템이 적응된 방식과는 다르다고 볼 수 있다. 즉 가상현실 내에서는 감각운동 시스템이 예측할 수 없는 환경에 적응하기 위해 다른 인지 전략을 취하게 된다. 환경에 따른 효율적인 인지전략의 전환은 중앙 집행기능(central executive)과 관련 있으며, 이러한 특징을 활용한 가상현실기반 과제는 새로운 인지기능 평가의 대안으로 제시할 수 있다.The purpose of this dissertation was to investigate information mismatch in virtual reality (VR) and explore the possibility of using the cognitive reaction arising from information mismatch for cognitive evaluation. The virtual kitchen task was used to observe the subjects’ behaviors while performing the task, and to investigate the characteristics of movement and cognitive processes appearing during the performance of the virtual task. In addition, an attempt was made to explore the factors of cognitive overload in VR that determine the difference compared to a performance in the real environment. In particular, this study aimed to investigate how information mismatch occurring in VR causes cognitive overload in terms of sensorimotor control. First, it questioned how the cognitive process in VR differs from the real environment and also investigated the factors affecting the performance of tasks in VR. In the young adult group, while there was a significant difference between the execution time in VR and in the real environment in the difficult kitchen task, there was no such difference in the easy kitchen task. Meanwhile, among the elderly, there was a significant difference between the execution time in VR and in the real environment regardless of whether the task was difficult or easy. It was thought that cognitive load was caused due to difficulties in sensorimotor control in VR. It was found that the cognitive capacity is challenged when the task is difficult because the load of task performance itself and the load of sensorimotor control are doubling. Second, it was found that as the cognitive function decreased, an abrupt and jerky movement pattern was exhibited during the virtual kitchen task. The number of sequences in movement until the task was completed was also busier in the elderly group with lower cognitive function in contrast with those with higher cognitive function. In the case of the elderly with deteriorated cognitive function, it is suggested that there is difficulty in minimal jerk movement control because the predictive ability responding to environment is decreased. In addition, according to the results of multiple regression, cognitive function of the elderly is the most influential factor in performing VR tasks, other than age and educational background, which means that purely evaluating cognitive function may be suggested. Third, an attempt was made to verify how the unpredictability of sensorimotor feedback causes cognitive load in VR. The reaction time and speed of movement depending on the predictability of perturbation were measured in implicit 5 degrees and explicit 15 degrees perturbation. When the subject was unable to predict the variation of perturbation only in implicit motor control, reaching became slower and it took more time due to the accuracy and speed trade-off. In other words, unpredictability due to information mismatch leads to the use of different cognitive strategies in brain mechanisms. In conclusion, VR induces more cognitive load than the real environment because the sensory feedback is unpredictable and variable due to technical fidelity problems. The sensorimotor control in VR is challenged by the way the human motor system is adapted. Further, it was found that an unpredictable environment requires different cognitive strategies for the sensorimotor system to adapt to it. The manner in which effective cognitive strategies are taken represents an efficient central executive function. From this perspective, VR-based cognitive evaluation, using such attributes, is thought to be an alternative method for early screening of cognitive decline.Chapter 1. Introduction 7 1.1 Research motivation and introductory overview 7 1.2 Research goal and questions 7 1.2.1 Overall research goal 7 1.2.2 Research questions 8 1.2.3 Research contributions 8 1.3 Thesis structure 8 Chapter 2. Literature Review 10 2.1 Virtual Reality (VR) as ecological method for cognitive evaluation 10 2.2 Sub-types of VR based tasks according to target cognitive function 12 2.2.1. VR task for spatial navigation 13 2.2.2. VR task for memory 14 2.2.3. VR task for executive function 16 2.3 Factors affecting on VR performance 19 2.3.1. General 19 2.3.2. Age effects on VR performance 20 2.3.3. Cognitive challenges in VR 21 2.3.4. Feasibility of VR task for dementia 22 2.4 Cognitive load in VR 23 2.4.1. Immersive versus non-immersive VR 23 2.4.2. Sense of presence and situated cognition 26 2.4.3. Sensorimotor adaptation in VR 28 2.5 Sensorimotor control in VR 29 2.5.1 Predictive brain and internal model for motor control 29 2.5.2 Explicit and implicit process in motor control 31 2.5.3 Accuracy & speed tradeoff in cognitive control 31 2.6 Executive control for information mismatch in information processing 32 Chapter 3. Differences in Cognitive Load Between Real and VR Environment 34 3.1 Introduction 34 3.2 Method 37 3.3 Results 40 3.4 Discussion 45 Chapter 4. The Efficiency of Movement Trajectory and Sequence in VR According to Cognitive Function in the Elderly 50 4.1 Introduction 50 4.2 Method 52 4.3 Results 53 4.4 Discussion 56 Chapter 5. Factors that Affect the Performance of Immersive Virtual Kitchen Tasks in the Elderly 59 5.1 Introduction 59 5.2 Method 62 5.3 Results 64 5.4 Discussion 70 Chapter 6. Effect of Predictability of Sensorimotor Feedback on Cognitive Load in VR 74 6.1 Introduction 74 6.2 Method 77 6.3 Results 79 6.4 Discussion 84 Chapter 7. Conclusion 88 7.1 Summary of findings 88 7.2 Future direction of research 90 References 92박

System development guidelines from a review of motion-based technology for people with MCI or dementia

As the population ages and the number of people living with dementia or mild cognitive impairment (MCI) continues to increase, it is critical to identify creative and innovative ways to support and improve their quality of life. Motion-based technology has shown significant potential for people living with dementia or MCI by providing opportunities for cognitive stimulation, physical activity and participation in meaningful leisure activities, while simultaneously functioning as a useful tool for research and development of interventions. However, many of the current systems created using motion-based technology have not been designed specifically for people with dementia or MCI. Additionally, the usability and accessibility of these systems for these populations has not been thoroughly considered. This paper presents a set of system development guidelines derived from a review of the state of the art of motion-based technologies for people with dementia or MCI. These guidelines highlight three overarching domains of consideration for systems targeting people with dementia or MCI: (i) cognitive, (ii) physical, and (iii) social. We present the guidelines in terms of relevant design and use considerations within these domains and the emergent design themes within each domain. Our hope is that these guidelines will aid in designing motion-based software to meet the needs of people with dementia or MCI such that the potential of these technologies can be realized

Use of Immersive Virtual Reality in the Assessment and Treatment of Alzheimer’s Disease: A Systematic Review

Background: Immersive virtual reality (iVR) allows seamless interaction with simulated environments and is becoming an established tool in clinical research. It is unclear whether iVR is acceptable to people with Alzheimer’s disease (AD) dementia or useful in their care. We explore whether iVR is a viable research tool that may aid the detection and treatment of AD. Objectives: This review examines the use of iVR in people with AD or mild cognitive impairment (MCI). Methods: Medline, PsycINFO, Embase, CINAHL, and Web of Science databases were searched from inception. PRISMA guidelines were used with studies selected by at least two researchers. Results: Nine studies were eligible for inclusion. None reported any issues with iVR tolerability in participants with MCI and AD on assessment or treatment tasks. One study demonstrated capability for detecting prodromal AD and correlated with neuroanatomical substrates. Two studies showed iVR to have high accuracy in differentiating participants with AD from controls but were not hypothesis driven or with adequate controls measures. In a small validation study and two longitudinal case studies, iVR cognitive training was positively rated but did not demonstrate reliable benefit. Conclusion: iVR is emerging as a viable method of assessing older adults and people with AD. Strongest benefits were seen when closely integrated with theoretical models of neurodegeneration and existing screening methods. Further randomized controlled trials integrated with clinical populations are required. This will consolidate the power of iVR for assessment of MCI and clarify treatment efficacy beyond current applications in physical rehabilitation

Use of Immersive Virtual Reality in the Assessment and Treatment of Alzheimer's Disease: A Systematic Review.

BACKGROUND: Immersive virtual reality (iVR) allows seamless interaction with simulated environments and is becoming an established tool in clinical research. It is unclear whether iVR is acceptable to people with Alzheimer's disease (AD) dementia or useful in their care. We explore whether iVR is a viable research tool that may aid the detection and treatment of AD. OBJECTIVES: This review examines the use of iVR in people with AD or mild cognitive impairment (MCI). METHODS: Medline, PsycINFO, Embase, CINAHL, and Web of Science databases were searched from inception. PRISMA guidelines were used with studies selected by at least two researchers. RESULTS: Nine studies were eligible for inclusion. None reported any issues with iVR tolerability in participants with MCI and AD on assessment or treatment tasks. One study demonstrated capability for detecting prodromal AD and correlated with neuroanatomical substrates. Two studies showed iVR to have high accuracy in differentiating participants with AD from controls but were not hypothesis driven or with adequate controls measures. In a small validation study and two longitudinal case studies, iVR cognitive training was positively rated but did not demonstrate reliable benefit. CONCLUSION: iVR is emerging as a viable method of assessing older adults and people with AD. Strongest benefits were seen when closely integrated with theoretical models of neurodegeneration and existing screening methods. Further randomized controlled trials integrated with clinical populations are required. This will consolidate the power of iVR for assessment of MCI and clarify treatment efficacy beyond current applications in physical rehabilitation

Measuring Memory in an Alzheimer's Treatment Trial Using a Visual Search Task

Alzheimer’s Disease (AD) is characterized by episodic memory deficits attributed to damage to the hippocampal formation. AD therapies specifically targeting hippocampal function may be best evaluated through the use of selective hippocampal tasks. I used a nonverbal hippocampal-dependent target-in-scene detection task to determine if task performance shows age-related decline and/or AD-related impairments. Participants located objects (‘targets’) that appeared/disappeared in flickering natural scenes, yielding faster search times for remembered targets than for forgotten ones. AD patients took longer and required more fixations to detect targets, indicating impaired memory. Furthermore, the AD and aged populations exhibited slower pupillary responses. As part of a clinical trial, I next asked whether deep-brain stimulation of the extended hippocampal circuit would modify memory performance in patients with early AD. The double-blind treatment trial is still underway, thus treatment efficacy is yet to be evaluated, however, trial participants showed a measurable, progressive memory impairment in this task

Cognitive stimulation and cognitive results in older adults: A systematic review and meta-analysis

Background and Purpose The lack of cognitive activity accelerates age cognitive decline. Cognitive stimulation (CS) tries to enhance cognitive functioning. The purpose of this systematic review and meta-analysis was to evaluate the effects of CS on cognitive outcomes (general cognitive functioning and specific cognitive domains) in older adults (aged 65 years or older, cognitively healthy participants, or with mild cognitive impairment, or dementia). Methods PubMed, Scopus and Web of Science databases were examined from inception to October 2021. A total of 1,997 studies were identified in these databases, and. 33 studies were finally included in the systematic review and the meta-analysis. Raw means and standard deviations were used for continuous outcomes. Publication bias was examined by Egger's Regression Test for Funnel Plot Asymmetry and the quality assessment tools from the National Institutes of Health. Results CS significantly improves general cognitive functioning (mean difference=MD = 1.536, 95%CI, 0.832 to 2.240), memory (MD = 0.365, 95%CI, 0.300 to 0.430), orientation (MD = 0.428, 95%CI, 0.306 to 0.550), praxis (MD = 0.278, 95%CI, 0.094 to 0.462) and calculation (MD = 0.228, 95%CI, 0.112 to 0.343). Conclusion CS seems to increase general cognitive functioning, memory, orientation, praxis, and calculation in older adults