Introducing a new age-and-cognition-sensitive measurement for assessing spatial orientation using a landmark-less virtual reality navigational task

Applicability of an immersive virtual reality system to assess egocentric orientation of older adults

BACKGROUND

Spatial orientation is a cognitive domain frequently compromised in patients with Alzheimer disease (AD) and may be one of its first clinical manifestations. Some studies have shown that allocentric integration with egocentric spatial information seems to be impaired in this pathology. There is no consensus on how best to assess spatial orientation and traditional tests lack ecological validity, but, recently, virtual reality (VR) has provided new opportunities for this assessment.

OBJECTIVES

To analyze the applicability and stability of an immersive virtual task developed to assess spatial orientation, the Spatial Orientation in Immersive Virtual Environment Maze Test (SOIVET-Maze) in older adults with and without mild cognitive impairment.

METHODS

Forty-three older adults were included in the study, 24 without cognitive impairment and 19 with mild cognitive impairment. Applicability was assessed by the Witmer and Singer Sense of Presence Questionnaire and a questionnaire for adverse events of cybersickness. To assess stability, participants were assessed twice with an interval of 7 to 14 days, and the intraclass correlation coefficient was calculated between visits. The t test or the Mann-Whitney test was used to compare applicability and stability between groups.

RESULTS

There was no significant difference between the groups regarding applicability. A strong correlation between the first and second day of testing was found in the mild cognitive impairment group.

CONCLUSION

The SOIVET-Maze task showed excellent applicability and good stability, favoring its clinical application for the evaluation of spatial orientation in older adults.

Applicability of an immersive virtual reality system for assessing route learning in older adults

Spatial orientation is defined as the ability to find one’s way around an environment, follow familiar routes, recognize places, and learn new routes. Spatial disorientation is one of the early symptoms of Alzheimer’s disease (AD), and traditional cognitive evaluation lacks ecological validity. Therefore, new assessment methods are needed for the early identification of this cognitive impairment.

Egocentric spatial orientation differences between Alzheimer's disease at early stages and mild cognitive impairment: a diagnostic aid

Alzheimer's disease (AD) is a growing global crisis. Egocentric spatial orientation deteriorates with age and more significantly with AD. A simple and quick virtual reality (VR) localization and target finding technique is presented as a diagnostic aid to screen mild cognitive impairment (MCI) from AD. Spatial orientation data from 93 individuals (65 AD at a mild stage, 20 MCI, and 8 other dementia types) based on VR localization of a target on a landmark-less cubic 3-story building were analyzed. We hypothesize AD and MCI groups' performances are significantly different. AD and MCI spatial performances were statistically significantly (p < 0.001) different. These results plus the longitudinal tracking of three patients who developed AD over a period of 5 years suggest the proposed spatial tests may be used as a quick and simple clinical diagnostic aid to separate AD at early to mild stages from MCI.

Do Older and Young Adults Learn to Integrate Geometry While Navigating in an Environment of a Serious Game?

We evaluated the outcomes of an intervention using a serious game designed to be played on iPads for improving spatial reorientation by training users to integrate geometry of the environment, instead of relying solely on featural cues. Using data logged online through a clinical study of using this game, the effect of training among 16 older adults (69.3 ± 6.4 years, 4 males), who played the game repeatedly (self-administered) over a period of 8 weeks, was investigated. The game contains a hexagonal room with 3 objects, textured walls, and grids on the floor, which are removed one by one as the participant played the game. In each level, the room also rotates such that the viewpoint of the user is different from that of the previous level. Participants cannot play a higher level unless they make no mistake during the trials of the lower test level. In addition to data of older adults available from that clinical trial, we recruited 16 young adults (27.3 ± 5.6 years, 4 males) to play the game for 5 sessions and compared their results with those of the older adults. We evaluated the error type made in each test level and the scores for each session among older adults. Further, we compared the frequency of each error type between young and older adults during the test levels that a landmark adjacent to the target was removed over the first 5 sessions. The results of older adults’ performance suggest they learned to make fewer mistakes over the sessions. Also, both young and older adults learned to integrate the geometrical cues rather than relying on the landmark cue adjacent to the target to find the target. Overall, the results indicate the designed hexagonal room game can enhance spatial cognition among all age groups of adults.

A Novel Program to Improve Cognitive Function in Individuals With Dementia Using Transcranial Alternating Current Stimulation (tACS) and Tutored Cognitive Exercises

The effects of cognitive exercises on the healthy aging population is controversial. Transcranial alternating current stimulation (tACS) is considered a promising tool for modulating brain oscillation. Research is lacking on its long-lasting cognitive/therapeutic effect. This is the first pilot study to explore the effect of a regimen of cognitive exercises with and without tACS on older adults with dementia. The study groups were 28 individuals (age 56–83 years) enrolled into two groups: Exr Group, who received cognitive exercises only and the Exr + tACS Group who received tACS at 40 Hz simultaneously with cognitive exercises for a period of 4 consecutive weeks, 5 days/week, two 30 min-sessions/day; all the training sessions were tutored. The cognitive exercises were applied using the MindTriggers app. They were assessed at pre and post intervention and also one month after the end of trial (follow-up) with an independent assessment (WMS-IV) as the primary outcome measure. The results show significant cognitive improvement at post-intervention in both groups, while the Exr + tACS protocol lead to superior cognitive improvement at follow-up session. The most important outcomes of this study are: 1) The tutored repeated practice of the MindTriggers app exercises does significantly improve the cognitive functions of older adults with dementia and that that improvement lasts for at least one month after the end of the intervention, and 2) The application of tACS increases the positive effects of cognitive exercises with the positive effect lasting an even longer period of time than exercises alone; in other words we speculate that it may lead to long-term potentiation.

Does Practicing with a Virtual Reality Driving Simulator Improve Spatial Cognition in Older Adults? A Pilot Study

Memory, cognition, executive functioning, and spatial cognition loss are prevalent in the normal aging process, but these impairments are observed more extensively in individuals with dementia, specifically Alzheimer’s disease. To improve the impaired functions, serious games targeting the lost functions are commonly developed and used in training programs. In this study, we designed a virtual reality driving simulator (VRDS) as a serious game with different difficulty levels for improving the spatial cognition; we evaluated it on 11 participants with different levels of dementia for two weeks, every day except weekends (10 sessions of practice in total) and 30 min/day. We assessed the participants’ spatial cognition before and after the intervention by an independent assessment (the VR replica of Morris Water test) and also by their performance playing the VRDS during the intervention. We also assessed the participants’ mood by a standard depression scale as well as their plausible experience of simulation sickness. The results showed significant improvement in Morris water test. The participants’ normalized correct trajectory (to find the target) was improved significantly by 44.4% at post-intervention with respect to baseline. Furthermore, on average, the participants progressed to higher (more challenging) levels of the game, and their spatial learning score increased throughout the sessions. Their mood also showed improvement with respect to baseline. Overall, the results hold promise for the designed VRDS as a mood-lifting and enhancing spatial skills serious game for older adults if it is played regularly.

Trial Registry name: Investigating the Effect of Training with a Virtual Reality Driving Simulator

URL: https://clinicaltrials.gov/ct2/show/NCT04074655

Clinical Trials.gov ID: NCT04074655

Spatial orientation tasks show moderate to high accuracy for the diagnosis of mild cognitive impairment: a systematic literature review

Abstract Spatial disorientation has been observed in mild cognitive impairment (MCI) and is associated with a higher risk of progression to Alzheimer's disease (AD). However, there is no gold standard assessment for spatial orientation and paper-and-pencil tests lack ecological validity. Recently, there has been an increasing number of studies demonstrating the role of spatial disorientation as a cognitive marker of pathological decline, shedding new light on its importance for MCI. This systematic review aimed to investigate the accuracy of spatial orientation tasks for the diagnosis of MCI by comparison with cognitively healthy elderly. The search was conducted in the databases Medical Literature Analysis and Retrieval System Online (MEDLINE/PubMed), Web of Science, Scopus, Excerpta Medica Database (Embase), Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs) and Scientific Electronic Library Online (SciELO). Only original studies reporting spatial orientation assessment in MCI patients compared to a healthy control group were included. Studies were excluded if the MCI classification did not follow well described criteria and/or if accuracy results of spatial orientation assessment were not provided. Seven studies met the eligibility criteria, describing a variety of spatial orientation assessments including questionnaires, paper-and-pencil, office-based route learning, and computer-based and virtual reality tasks. Spatial orientation tasks demonstrated moderate to high accuracy in detecting elderly with MCI compared to cognitively healthy elderly, with areas under the curve (AUC) ranging from 0.77 to 0.99. However, important methodological issues were found in the selected studies which should be considered when interpreting results. Although the inclusion of spatial orientation assessments in MCI evaluations seems to have significant value, further studies are needed to clarify their true capacity to distinguish pathological from non-pathological aging.

Older Adults Show Less Flexible Spatial Cue Use When Navigating in a Virtual Reality Environment Compared With Younger Adults

Daily life requires accurate navigation, and thus better understanding of aging on navigational abilities is critical. Importantly, the use of spatial properties by older and younger adults remains unclear. During this study, younger and older human adults were presented with a virtual environment in which they had to navigate a series of hallways. The hallways provided 2 general types of spatial information: geometric, which included distance and directional turns along a learned route, and featural, which included landmarks situated along the route. To investigate how participants used these different cue types, geometric and/or landmark information was manipulated during testing trials. Data from 40 younger (20 women) and 40 older (20 women) adults were analyzed. Our findings suggest that (1) both younger and older adults relied mostly on landmarks to find their way, and (2) younger adults were better able to adapt to spatial changes to the environment compared with older adults.

Effects of virtual reality technology locomotive multi-sensory motion stimuli on a user simulator sickness and controller intuitiveness during a navigation task

Simulator sickness of users and intuitiveness of controllers contribute to a user's acceptance or rejection of a virtual reality (VR) experiment. However, few studies investigated the effects of different VR locomotive controllers and potential gender effects. Hence, we investigated the effects of different motion stimuli combinations and a user's range of neck motion via two experiments in a gender balanced group. Thus, through separate sessions, young adult participants utilized four common VR locomotive controllers (TiltChair, omni-directional treadmill, VRNChair and joystick) with a head-mounted display to execute the same VR navigation task as we measured simulator sickness by the simulator sickness questionnaire and postural sway. Also, we measured intuitiveness through total traversed distance and execution times. As expected, simulator sickness severity increased with VR exposure time. However, participants had significantly shorter traversed distances and execution times when they utilized the TiltChair and joystick respectively; while, participants had significantly longer execution times when they utilized the omni-directional treadmill. Additionally, female participants easily utilized the TiltChair and omni-directional treadmill because they traversed shorter distances than male participants. Therefore, a VR locomotive controller selection should be based on a target population's characteristics to reduce user simulator sickness and to increase controller intuitiveness. Graphical Abstract The current study investigates the use different virtual reality locomotive controllers to minimize user simulator sickness and maximize controller intuitiveness.

Orientation in Virtual Reality Does Not Fully Measure Up to the Real-World

Adult participants learned to reorient to a specific corner inside either a real or virtual rectangular room containing a distinct featural object in each corner. Participants in the virtual-reality (VR) condition experienced an immersive virtual version of the physical room using a head-mounted display (HMD) and customized manual wheelchair to provide self-movement. Following a disorientation procedure, people could reorient by using either the geometry of the room and/or the distinct features in the corners. Test trials in which the different spatial cues were manipulated revealed participants encoded features and geometry in both the real and VR rooms. However, participants in the VR room showed less facility with using geometry. Our results suggest caution must be taken when interpreting the nuances of spatial cue use in virtual environments. Reduced reliability of geometric cues in VR environments may result in greater reliance on feature cues than would normally be expected under similar real-world conditions.

Neurocognitive Treatment for a Patient with Alzheimer's Disease Using a Virtual Reality Navigational Environment

In this case study, a man at the onset of Alzheimer’s disease (AD) was enrolled in a cognitive treatment program based upon spatial navigation in a virtual reality (VR) environment. We trained him to navigate to targets in a symmetric, landmark-less virtual building. Our research goals were to determine whether an individual with AD could learn to navigate in a simple VR navigation (VRN) environment and whether that training could also bring real-life cognitive benefits. The results show that our participant learned to perfectly navigate to desired targets in the VRN environment over the course of the training program. Furthermore, subjective feedback from his primary caregiver (his wife) indicated that his skill at navigating while driving improved noticeably and that he enjoyed cognitive improvement in his daily life at home. These results suggest that VRN treatments might benefit other people with AD.