A virtual reality extended neuropsychological assessment for topographical disorientation: a feasibility study

<p>Abstract</p> <p>Background</p> <p>Topographical disorientation represents one of the main consequences of brain injury. Up to now several methodological approaches have been used in the assessment of the brain injured patient's navigational abilities showing a moderate correlation with the impairments observed in everyday contexts.</p> <p>Methods</p> <p>We propose a combination of standardized neuropsychological tests and a more situated virtual reality-based assessment for the evaluation of spatial orientation in brain injured patients.</p> <p>Results</p> <p>When tested with this virtual reality integrated procedure patients showed performance and execution times congruent with their neuropsychological evaluation. When compared to a control group, patients revealed significantly slower times and greater errors in solving virtual reality based spatial tasks.</p> <p>Conclusion</p> <p>The use of virtual reality, when combined with classical neuropsychological tests, can provide an effective tool for the study of topographical disorientation.</p

Lost in spatial translation - A novel tool to objectively assess spatial disorientation in Alzheimer's disease and frontotemporal dementia

Spatial disorientation is a prominent feature of early Alzheimer's disease (AD) attributed to degeneration of medial temporal and parietal brain regions, including the retrosplenial cortex (RSC). By contrast, frontotemporal dementia (FTD) syndromes show generally intact spatial orientation at presentation. However, currently no clinical tasks are routinely administered to objectively assess spatial orientation in these neurodegenerative conditions. In this study we investigated spatial orientation in 58 dementia patients and 23 healthy controls using a novel virtual supermarket task as well as voxel-based morphometry (VBM). We compared performance on this task with visual and verbal memory function, which has traditionally been used to discriminate between AD and FTD. Participants viewed a series of videos from a first person perspective travelling through a virtual supermarket and were required to maintain orientation to a starting location. Analyses revealed significantly impaired spatial orientation in AD, compared to FTD patient groups. Spatial orientation performance was found to discriminate AD and FTD patient groups to a very high degree at presentation. More importantly, integrity of the RSC was identified as a key neural correlate of orientation performance. These findings confirm the notion that i) it is feasible to assess spatial orientation objectively via our novel Supermarket task; ii) impaired orientation is a prominent feature that can be applied clinically to discriminate between AD and FTD and iii) the RSC emerges as a critical biomarker to assess spatial orientation deficits in these neurodegenerative conditions

The use of virtual environments for survey spatial ability evaluation in topographical disorientation

Due to their interactivity and to the sense of presence they afford, virtual environments constitute an interesting opportunity to study spatial cognition. In accordance with this perspective, we aimed to introduce a spatial test in virtual simulation in order to investigate the survey spatial ability in patients with topographical disorientation. To do this, we used the “planning in advance task” in a virtual environment that constitutes an effective procedure to experimentally evaluate survey maps. With this procedure we present the single case of a woman, with a right medial temporal lobe lesion, who shows a selective impairment in the acquisition of new spatial relationships. The patient’s performance in “planning in advance task” was compared with that of a control group made up of 40 female subjects matched for age and education. Results show how the patient revealed a significantly lower spatial performance when compared to the control group, demonstrating an inability to solve survey-type spatial tasks in complex virtual environments

Virtual reality in neurologic rehabilitation of spatial disorientation

BACKGROUND: Topographical disorientation (TD) is a severe and persistent impairment of spatial orientation and navigation in familiar as well as new environments and a common consequence of brain damage. Virtual reality (VR) provides a new tool for the assessment and rehabilitation of TD. In VR training programs different degrees of active motor control over navigation may be implemented (i.e. more passive spatial navigation vs. more active). Increasing demands of active motor control may overload those visuo-spatial resources necessary for learning spatial orientation and navigation. In the present study we used a VR-based verbally-guided passive navigation training program to improve general spatial abilities in neurologic patients with spatial disorientation. METHODS: Eleven neurologic patients with focal brain lesions, which showed deficits in spatial orientation, as well as 11 neurologic healthy controls performed a route finding training in a virtual environment. Participants learned and recalled different routes for navigation in a virtual city over five training sessions. Before and after VR training, general spatial abilities were assessed with standardized neuropsychological tests. RESULTS: Route finding ability in the VR task increased over the five training sessions. Moreover, both groups improved different aspects of spatial abilities after VR training in comparison to the spatial performance before VR training. CONCLUSIONS: Verbally-guided passive navigation training in VR enhances general spatial cognition in neurologic patients with spatial disorientation as well as in healthy controls and can therefore be useful in the rehabilitation of spatial deficits associated with TD

Egocentric versus Allocentric Spatial Memory in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease

Background: Diagnosis of behavioural variant frontotemporal dementia (bvFTD) can be challenging, in particular when patients present with significant memory problems, which can increase the chance of a misdiagnosis of Alzheimer’s disease (AD). Growing evidence suggests spatial orientation is a reliable cognitive marker able to differentiate these two clinical syndromes. Objective: Assess the integrity of egocentric and allocentric heading orientation and memory in bvFTD and AD, and their clinical implications. Method: A cohort of 22 patient with dementia (11 bvFTD; 11 AD) and 14 healthy controls were assessed on the virtual supermarket task of spatial orientation and a battery of standardized neuropsychological measures of visual and verbal memory performance. Results: Judgements of egocentric and allocentric heading direction were differentially impaired in bvFTD and AD, with AD performing significantly worse on egocentric heading judgements than bvFTD. Both patient cohorts, however, showed similar degree of impaired allocentric spatial representation, and associated hippocampal pathology. Conclusions: The findings suggest egocentric heading judgements offer a more sensitive discriminant of bvFTD and AD than allocentric map-based measures of spatial memory

Learning in the navigational space: Age differences in a short-term memory for objects task Learning and Individual Differences

Age differences during development in visuospatial short-termmemory (VSTM) in navigation have not been sufficiently proven. The performance of typically developing children from five age groups (from 5 to 9 years old) and one group of young adults (from 25 to 30 years old) was studied in an Augmented Reality navigational VSTM task that involved remembering the location of objects presented in increasing span lengths. The main results showed that navigational VSTM has not fully developed at the age of 9. The measures of performance significantly improved between ages 8 and 9. The overall performance on our navigational task was not influenced by gender, but therewas a slight advantage for maleswhen the difficulty of the task increased regarding the performance accuracy and the errors committed. The Augmented Reality task correlated with traditional spatial tests. Possible cognitive, biological, and methodological explanations for the findings are discussed.This work was funded mainly by the Spanish Ministry of Economy and Competitiveness (MINECO) through the CHILDMNEMOS project (TIN2012-37381-C02-01) and confinanced by the European Regional Development Fund (FEDER). Other financial support was received from the Gobierno de Aragon (Departamento de Industria e Innovacion), Fondo Social Europeo for Aragon, Fundacion Universitaria Antonio Gargallo, and Obra Social Ibercaja. We would like to thank the following for their contributions: the "Escola d'Estiu" and especially Juan Cano, Miguelon Gimenez, and Javier Irimia; the ETSInf for letting us use its facilities; the children who participated in the study and their parents who filled out the parent's questionnaires.Mendez Lopez, M.; Pérez Hernández, E.; Juan, M. (2016). Learning in the navigational space: Age differences in a short-term memory for objects task Learning and Individual Differences. Learning and Individual Differences. 50:11-22. https://doi.org/10.1016/j.lindif.2016.06.028S11225

Egocentric and allocentric spatial reference frames in aging: A systematic review

Abstract Aging affects many aspects of everyday living, such as autonomy, security and quality of life. Among all, spatial memory and spatial navigation show a gradual but noticeable decline, as a result of both neurobiological changes and the general slowing down of cognitive functioning. We conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify studies that specifically investigated the role of allocentric and egocentric frames in healthy aging. Concerning spatial navigation, our results showed a preservation of egocentric strategies, along with specific impairments in the use of allocentric and switching abilities. Regarding spatial memory, instead, outcomes were more divergent and not frame-specific. With this perspective, spatial impairments were discussed considering the cognitive profile of mild cognitive impairment (MCI) and Alzheimer's Disease (AD)

Differences in spatial memory recognition due to cognitive style

Field independence refers to the ability to perceive details from the surrounding context as a whole and to represent the environment by relying on an internal reference frame. Conversely, field dependence individuals tend to focus their attention on single environmental features analysing them individually. This cognitive style affects several visuo-spatial abilities including spatial memory. This study assesses both the effect of field independence and field dependence on performance displayed on virtual environments of different complexity. Forty young healthy individuals took part in this study. Participants performed the Embedded Figures Test for field independence or dependence assessment and a new spatial memory recognition test. The spatial memory recognition test demanded to memorize a green box location in a virtual room picture. Thereafter, during ten trials participants had to decide if a green box was located in the same position as in the sample picture. Five of the pictures were correct. The information available in the virtual room was manipulated. Hence, two different experimental conditions were tested: a virtual room containing all landmarks and a virtual room with only two cues. Accuracy and reaction time were registered. Analyses demonstrated that higher field independent individuals were related to better spatial memory performance in two landmarks condition and were faster in all landmark condition. In addition, men and women did not differ in their performance. These results suggested that cognitive style affects spatial memory performance and this phenomenon is modulated by environment complexity. This does not affect accuracy but time spent. Moreover, field dependent individuals are unable to organize the navigational field by relying on internal reference frames when few landmarks are available, and this causes them to commit more errors