Age-related wayfinding differences in real large-scale environments: detrimental motor control effects during spatial learning are mediated by executive decline?

“CityQuest,” A Custom-Designed Serious Game, Enhances Spatial Memory Performance in Older Adults

Spatial cognition is known to decline with aging. However, little is known about whether training can reduce or eliminate age-related deficits in spatial memory. We investigated whether a custom-designed video game involving spatial navigation, obstacle avoidance, and balance control would improve spatial memory in older adults. Specifically, 56 healthy adults aged 65 to 84 years received 10 sessions of multicomponent video game training, based on a virtual cityscape, over 5 weeks. Participants were allocated to one of three training conditions: the main intervention, the “CityQuest” group (n = 19), and two control groups, spatial navigation without obstacle avoidance (“Spatial Navigation-only” group, n = 21) and obstacle avoidance without spatial navigation (“Obstacles-only” group, n = 15). Performance on object recognition, egocentric and allocentric spatial memory (incorporating direction judgment tasks and landmark location tasks, respectively), navigation strategy preference, and executive functioning was assessed in pre- and post-intervention sessions. The results showed an overall benefit on performance in a number of spatial memory measures and executive function for participants who received spatial navigation training, particularly the CityQuest group, who also showed significant improvement on the landmark location task. However, there was no evidence of a shift from egocentric to allocentric strategy preference. We conclude that spatial memory in healthy older participants is amenable to improvement with training over a short term. Moreover, technology based on age-appropriate, multicomponent video games may play a key role in cognitive training in older adults.

Early loss of cerebellar Purkinje cells in human and a transgenic mouse model of Alzheimer's disease

BACKGROUND

The cerebellum's involvement in AD has been under-appreciated by historically labeling as a normal control in AD research.

METHODS

We determined the involvement of the cerebellum in AD progression. Postmortem human and APPswe/PSEN1dE9 mice cerebellums were used to assess the cerebellar Purkinje cells (PC) by immunohistochemistry. The locomotor and spatial cognitive functions were assessed in 4- to 5-month-old APPswe/PSEN1dE9 mice. Aβ plaque and APP processing were determined in APPswe/PSEN1dE9 mice at different age groups by immunohistochemistry and Western blot.

RESULTS

We observed loss of cerebellar PC in mild cognitive impairment and AD patients compared with cognitively normal controls. A strong trend towards PC loss was found in AD mice as early as 5 months. Impairment of balance beam and rotorod performance, but no spatial learning and memory dysfunction was observed in AD mice at 4-5 months. Aβ plaque in the cerebral cortex was evidenced in AD mice at 2 months and dramatically increased at 6 months. Less and smaller Aβ plaques were observed in the cerebellum than in the cerebrum of AD mice. Similar intracellular APP staining was observed in the cerebellum and cerebrum of AD mice at 2 to 10 months. Similar expression of full-length APP and C-terminal fragments were indicated in the cerebrum and cerebellum of AD mice during aging.

DISCUSSION

Our study in post-mortem human brains and transgenic AD mice provided neuropathological and functional evidence that cerebellar dysfunction may occur at the early stage of AD and likely independent of Aβ plaque.

A novel virtual-reality-based route-learning test suite: Assessing the effects of cognitive aging on navigation

Most research groups studying human navigational behavior with virtual environment (VE) technology develop their own tasks and protocols. This makes it difficult to compare results between groups and to create normative data sets for any specific navigational task. Such norms, however, are prerequisites for the use of navigation assessments as diagnostic tools—for example, to support the early and differential diagnosis of atypical aging. Here we start addressing these problems by presenting and evaluating a new navigation test suite that we make freely available to other researchers (https://osf.io/mx52y/). Specifically, we designed three navigational tasks, which are adaptations of earlier published tasks used to study the effects of typical and atypical aging on navigation: a route-repetition task that can be solved using egocentric navigation strategies, and route-retracing and directional-approach tasks that both require allocentric spatial processing. Despite introducing a number of changes to the original tasks to make them look more realistic and ecologically valid, and therefore easy to explain to people unfamiliar with a VE or who have cognitive impairments, we replicated the findings from the original studies. Specifically, we found general age-related declines in navigation performance and additional specific difficulties in tasks that required allocentric processes. These findings demonstrate that our new tasks have task demands similar to those of the original tasks, and are thus suited to be used more widely.

Postural Control While Walking Interferes With Spatial Learning in Older Adults Navigating in a Real Environment

Cognitive demands for postural control increase with aging and cognitive-motor interference (CMI) exists for a number of walking situations, especially with visuo-spatial cognitive tasks. Such interference also influences spatial learning abilities among older adults; however, this is rarely considered in research on aging in spatial navigation. We posited that visually and physically exploring an unknown environment may be subject to CMI for older adults. We investigated potential indicators of postural control interfering with spatial learning. Given known associations between age-related alterations in gait and brain structure, we also examined potential neuroanatomical correlates of this interference. Fourteen young and 14 older adults had to find an invisible goal in an unfamiliar, real, ecological environment. We measured walking speed, trajectory efficiency (direct route over taken route) and goal fixations (proportion of visual fixations toward the goal area). We calculated the change in walking speed between the first and last trials and adaptation indices for all three variables to quantify their modulation across learning trials. All participants were screened with a battery of visuo-cognitive tests. Eighteen of our participants (10 young, 8 older) also underwent a magnetic resonance imaging (MRI) examination. Older adults reduced their walking speed considerably on the first, compared to the last trial. The adaptation index of walking speed correlated positively with those of trajectory efficiency and goal fixations, indicating a reduction in resource sharing between walking and encoding the environment. The change in walking speed correlated negatively with gray matter volume in superior parietal and occipital regions and the precuneus. We interpret older adults’ change in walking speed as indicative of CMI, similar to dual task costs. This is supported by the correlations between the adaptation indices and between the change in walking speed and gray matter volume in brain regions that are important for navigation, given that they are involved in visual attention, sensory integration and encoding of space. These findings under ecological conditions in a natural spatial learning task question what constitutes dual tasking in older adults and they can lead future research to reconsider the actual cognitive burden of postural control in aging navigation research.

Role of cognitive resources on everyday functioning among oldest-old physically frail

BACKGROUND

Everyday functioning becomes a challenge with aging, particularly among frail oldest-old adults. Several factors have been identified as influencing everyday activities realization, including physical and cognitive functioning. However, the influence of cognitive resources as a compensatory factor in the context of physical frailty deserves further consideration.

AIMS

This study aims to investigate in older adults physically frail the possible compensatory role of cognitive resources to perform everyday tasks.

METHODS

Two groups of community-dwelling old participants (n = 26 per group) matched for their age and cognitive resources, have been drawn according to their level of physical functioning. Two measures of everyday functioning have been assessed: one self-reported by the participant (the IADL scale) and one performance-based measure (the TIADL tasks).

RESULTS

Participants performed equally the TIADL tasks irrespective of their physical condition. Contrariwise, participants with low physical functioning reported more everyday difficulties than their counterparts with a high level of physical functioning. Additionally, regressions analyses revealed differential influence of cognitive resources on performance and reported measures of everyday functioning.

DISCUSSION

Our data suggests that cognitive resources are more strongly involved in the performance-based IADL measure in situation of physical frailty. Additionally, for participants with low physical functioning, lower cognitive resources are associated with more perceived difficulties in everyday life.

CONCLUSION

These results highlight the compensatory role of cognitive resources in physically frail older adults, and suggest that an overestimation of everyday difficulties compared to performance on IADL tasks is an early indicator of physical decline and cognitive compensation.

Being in the Past and Perform the Future in a Virtual World: VR Applications to Assess and Enhance Episodic and Prospective Memory in Normal and Pathological Aging

The process of aging commonly features a gradual deterioration in cognitive performance and, in particular, the decline of memory. Despite the increased longevity of the world’s population, the prevalence of neurodegenerative conditions, such as dementia, continues to be a major burden on public health, and consequently, the latest research has been focused on memory and aging. Currently, the failure of episodic and Prospective memory (PM) is one of the main complaints in the elderly, considered among the early symptoms of dementia. It is therefore increasingly important to define more clearly the boundaries between normal and pathological aging. Recently, researchers have begun to build and apply Virtual Environments (VE) to the explicit purpose of better understanding the performance of episodic and PM in complex and realistic contexts, with the perspective of further developing effective training procedures that depend on reliable cognitive assessment methods. Virtual technology offers higher levels of realism than “pen and paper” testing and at the same time more experimental control than naturalistic settings. In this mini-review article, we examine the outcomes of recently available studies on virtual reality technology applications developed for the assessment and improvement of episodic and/or PM. To consider the latest technology, we selected 29 articles that have been published in the last 10 years. These documents show that VR-based technologies can provide a valid basis for screening and treatment and, through increased sensory stimulation and enriched environments reproducing the scenarios of everyday life, could represent effective stimulating experiences even in pathological aging.

How age relates to spatial navigation performance: Functional and methodological considerations

Aging effects have often been reported for spatial navigation performance. Moreover, navigation performance is thought to be an early marker of pathological aging. Yet, the cognitive complexity of navigation and large individual variation in healthy population make it difficult to pinpoint the precise aging mechanisms involved. We performed a systematic literature review with specific attention to functional dissociation between the tasks used and methodological characteristics. The literature search resulted in 39 articles in which age comparisons were made for large-scale navigation measures. Outcomes were categorized into the domains of landmark, location (egocentric and allocentric), and path knowledge (route and survey). Results indicate that clear functional dissociation exists between these navigation knowledge domains. Aging effects are found for path knowledge most convincingly, while landmark and egocentric location knowledge are frequently omitted in assessment. The participant samples reported often neglect adult, middle aged participants, while this group could be highly informative to the aging process as well. Moreover, having a clear image of age-related performance across the lifespan could be a valuable addition towards the early detection of pathological aging through navigation performance.

Virtual reality in episodic memory research: A review

Although virtual reality (VR) is a promising tool for the investigation of episodic memory phenomena, to date there has been relatively little examination of how learning mechanisms operate in VR and how these processes might compare (or contrast) with learning that occurs in real life. Moreover, the existing literature on this topic is spread across several disciplines and uses various distinct apparatuses, thus obscuring whether the differences that exist between studies might be due to genuine theoretical discrepancies or may be more simply explained by accounting for methodological variations. The current review is designed to address and elucidate several issues relevant to psychological researchers interested in understanding and/or using this technological approach to study episodic memory phenomena. The principle objectives of the review are as follows: (a) defining and discussing the various VR systems currently used for research purposes, (b) compiling research of episodic memory effects in VR as they have been studied across several disciplines, and (c) surveying major topics in this body of literature (e.g., how virtual immersion has an impact on memory; transfer effects from VR to the real world). The content of this review is designed to serve as a resource for psychologists interested in learning more about the current state of research in this field and is intended to highlight the capabilities (and constraints) associated with using this technological approach in episodic memory research.

Navigation strategy in macaque monkeys: An exploratory experiment in virtual reality

BACKGROUND

Spatial memory and navigation have been widely studied using animal models, most of them were performed with rodents and only few of them with non-human primates. Also, most of these studies were achieved in simple and small-scale mazes.

NEW METHOD

In order to test navigation strategy in macaque monkeys, we used a double-cross virtual maze in which they could freely move using a joystick and a procedure adapted from previous studies with rodents. The monkeys had first to learn several routes from a specific starting point to reach separate positions, each one containing distinct symbols, and then to associate each route with these symbols. After this phase, the monkeys had to reach these targets from a second starting point positioned at the other end of the maze, requiring the use an allocentric strategy. In order to evaluate monkey's strategy, we analyzed monkey's first choice as a function of the symbol presented.

RESULTS

The monkeys were able to learn routes and to associate routes with symbols but were not able to use an allocentric strategy. They also did not use the procedural strategy and seemed disoriented or adopted a stereotypical behavior.

COMPARISON WITH EXISTING METHOD(S)

Contrary to the few studies using small-scale environments, the monkeys seemed unable to solve the allocentric task. The studies using virtual mazes seemed not to specifically analyze monkey's navigation strategy.

CONCLUSIONS

Supplementary experiments will be necessary to explain the origin of the monkey's inability to use an allocentric strategy. Modified learning conditions could also incite the monkeys to develop an allocentric representation.

Effects of Traditional vs. iPad-Enhanced Aerobic Exercise on Wayfinding Efficacy and Cognition: A Pilot Randomized Controlled Trial

The purpose of this pilot study was to test the feasibility and efficacy of an iPad-enhanced aerobic exercise intervention designed to enhance wayfinding efficacy and performance and relevant cognitive functioning among middle-aged adults at risk for cognitive impairment. Twenty-seven low active adults (21 females) aged 45 to 62 years (51.22 ± 5.20) participated in a ten-week randomized controlled trial. Participants were randomized to an iPad-enhanced aerobic exercise group (experimental group) or an aerobic exercise-only group (control group) following baseline assessment. Both groups exercised at 50% to 75% of age-predicted heart rate maximum for 30 to 50 min/d, 2 d/wk for 10 weeks. During aerobic exercise, the experimental group engaged in virtual tours delivered via iPad. Baseline and post-intervention assessments of wayfinding self-efficacy, wayfinding task performance, cognitive functioning, electroencephalogram (EEG), and psychosocial questionnaires were administered. The results suggest that ten weeks of iPad-enhanced, moderately intense aerobic exercise had specific effects on wayfinding self-efficacy; however, no statistical differences were found between groups on the behavioral wayfinding task or spatial memory performance at follow-up. Performance scores on an inhibitory attentional-control cognitive assessment revealed significant differences between groups, favoring the experimental group (p < 0.05). Virtual reality-enhanced aerobic exercise may prove to be an effective method for improving cognitive function and increasing confidence to navigate real-world scenarios among individuals at risk of cognitive impairment.

Effect of age on spatial memory performance in real museum vs. computer simulation

BACKGROUND

Healthy older adults frequently complain on difficulty in recalling the locations of objects of everyday use. Cognitive abilities decline with normal aging; inefficiencies of information processing, as well as deterioration of neuronal structures, may impede the performance of complex cognitive skills such as spatial memory. Extraneous, task-irrelevant cognitive load in real environments is usually high and might interfere with spatial memory abilities of older adults. The purpose of this study was to determine (1) the extent to which older adults maintain their cognitive capacity during a spatial memory task as compared to young adults and (2) whether this capacity is affected by performance of the task in a real environment setting where the cognitive demands are similar to a simulation, but the physical demands (navigating via walking versus via a mouse) vary.

METHODS

In the museum, participants physically moved between display stations to locate hidden tokens performing a task in which an ongoing representation of previous searches had to be remembered. A comparable task was implemented via mouse actions on a computer simulation. Seventeen healthy older (60-80 years) and twenty younger (20-45 years) adults performed both tasks in a counterbalanced order.

RESULTS

The younger group was superior to the older group in terms of success rate and completion time for both conditions. All participants performed better during the simulated task. The delta between the total performance score in the two settings of the older group was significantly larger as compared to the younger group, suggesting a differential impact of setting on the groups.

CONCLUSIONS

Our results highlight the importance and feasibility of experimentation in ecologically relevant settings: differences were found in the way the cognitive performance of older and younger adults was affected by setting. Older adults appear to preserve basic cognitive abilities required for successful performance of object-location memory tasks. However, real museum setting appeared to impose higher demands on the older adults.

Virtual Enactment Effect on Memory in Young and Aged Populations: a Systematic Review

BACKGROUND

Spatial cognition is a critical aspect of episodic memory, as it provides the scaffold for events and enables successful retrieval. Virtual enactment (sensorimotor and cognitive interaction) by means of input devices within virtual environments provides an excellent opportunity to enhance encoding and to support memory retrieval with useful traces in the brain compared to passive observation.

METHODS

We conducted a systematic review with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines concerning the virtual enactment effect on spatial and episodic memory in young and aged populations. We aim at giving guidelines for virtual enactment studies, especially in the context of aging, where spatial and episodic memory decline.

RESULTS

Our findings reveal a positive effect on spatial and episodic memory in the young population and promising outcomes in aging. Several cognitive factors (e.g., executive function, decision-making, and visual components) mediate memory performances. Findings should be taken into account for future interventions in aging.

CONCLUSIONS

The present review sheds light on the key role of the sensorimotor and cognitive systems for memory rehabilitation by means of a more ecological tool such as virtual reality and stresses the importance of the body for cognition, endorsing the view of an embodied mind.

Predictors of Performance in Real and Virtual Scenarios across Age

BACKGROUND

Virtual reality applications to assist older adult with cognitive and functional decline are fast growing. However, such technological developments face limitations such as due to limited constructs and ecological validity. This study was aimed at investigating age-related changes in functional abilities and their associated cognitive underpinnings during task performance in virtual and real environments.

METHOD

Twenty-two younger adults (university students) and 22 older adults (aged 58-74) performed a multiple errands task twice, once in the "Discoveries" section of the National Museum of Scotland and once in the same room as a virtual environment. Accuracy and distance traveled were measured in both groups. Cognitive and daily living abilities were recorded in older adults using standard and novel questionnaires.

RESULTS

The testing environment had a significant effect on how efficient individuals performed the task. Older and younger adults' performance was alike but older adults relied on more cognitive resources. Older adults struggled in the virtual but not in the real environment. Younger but not older adults could transfer knowledge between environments.

CONCLUSION

The use of technology to assist frail older adults and those affected by dementia is growing rapidly. For these novel tools to be theoretically valid, they need to incorporate knowledge of the challenges they pose to these vulnerable groups. Here we present evidence of such challenges and their cognitive underpinnings. This theory may be considered by future applications aimed at enhancing functional abilities in these populations.

Driving while navigating: On-road driving performance using GPS or printed instructions

BACKGROUND.

Route navigation is a high-level skill and requires intact executive functioning to successfully find one's way while driving in unfamiliar environments.

PURPOSE.

Driving performances were compared while navigating using electronic devices and printed directions on unfamiliar driving routes as well as in an interactive driving simulator.

METHOD.

Twenty-four participants drove two on-road routes using GPS and printed directions, and navigated using printed directions in the simulator, using a point system to evaluate performance. The two unfamiliar routes, order of simulator and on-road driving, and use of GPS and printed directions were counterbalanced. Paired t test were used to compare both GPS versus printed directions and performance between on-road driving and the simulator.

FINDINGS.

Participants' performance using GPS on the road was significantly better than with printed directions. There was no significant difference between performance in the simulator and on the road.

IMPLICATIONS.

Using GPS may be an effective strategy for improving safety. Using a driving simulator may be an efficient means of evaluating the strategic level of driving, executive function, and readiness to drive.

Gender and Age Differences in Using Indoor Maps for Wayfinding in Real Environments

Users more easily become lost in complex indoor environments than in outdoor environments. Users with diverse backgrounds encounter different self-location, route memorization, and route following problems during wayfinding. This study intends to explore gender and age effects on the use of indoor maps for wayfinding in real environments. We used eye-tracking and retrospective verbal protocol methods to conduct a wayfinding experiment in a newly opened building. Statistical data were collected and three findings were obtained. Finding 1: Males had no significant differences with females in indoor self-location, route reading, and route following. However, males paid less visual attention to the landmark and legend than females during route reading. Finding 2: Age-related differences were significant in indoor wayfinding. Younger adults generally outperformed elderly adults in wayfinding in real indoor environments. Finding 3: Gender and age interactive effects were significant in self-location and route memorization. The mean differences of visual attention on the self-location map reading and route memorization between males and females increased with age.

Extrahippocampal Contributions to Age-Related Changes in Spatial Navigation Ability

Age-related decline in spatial navigation is well-known and the extant literature emphasizes the important contributions of a hippocampus-dependent spatial navigation system in mediating this decline. However, navigation is a multifaceted cognitive domain and some aspects of age-related navigational decline may be mediated by extrahippocampal brain regions and/or systems. The current review presents an overview of some key cognitive domains that contribute to the age-related changes in spatial navigation ability, and elucidates such domains in the context of an increased engagement of navigationally relevant extrahippocampal brain regions with advancing age. Specifically, this review focuses on age-related declines in three main areas: (i) allocentric strategy use and switching between egocentric and allocentric strategies, (ii) associative learning of landmarks/locations and heading directions, and (iii) executive functioning and attention. Thus far, there is accumulating neuroimaging evidence supporting the functional relevance of the striatum for egocentric/response strategy use in older adults, and of the prefrontal cortex for mediating executive functions that contribute to successful navigational performance. Notably, the functional role of the prefrontal cortex was particularly emphasized via the proposed relevance of the fronto-locus coeruleus noradrenergic system for strategy switching and of the fronto-hippocampal circuit for landmark-direction associative learning. In view of these putative prefrontal contributions to navigation-related functions, we recommend future spatial navigation studies to adopt a systems-oriented approach that investigates age-related alterations in the interaction between the prefrontal cortex, the hippocampus, and extrahippocampal regions, as well as an individual differences approach that clarifies the differential engagement of prefrontal executive processes among older adults.

Map learning and working memory: Multimodal learning strategies

The current research investigated whether learning spatial information from a map involves different modalities, which are managed by discrete components in working memory. In four experiments, participants studied a map either while performing a simultaneous interference task (high cognitive load) or without interference (low cognitive load). The modality of interference varied between experiments. Experiment 1 used a tapping task (visuospatial), Experiment 2 a backward counting task (verbal), Experiment 3 an articulatory suppression task (verbal) and Experiment 4 an n-back task (central executive). Spatial recall was assessed in two tests: directional judgements and map drawing. Cognitive load was found to affect spatial recall detrimentally regardless of interference modality. The findings suggest that when learning maps, people use a multimodal learning strategy, utilising resources from all components of working memory.

Computerized cognitive training during physical inactivity improves executive functioning in older adults

The hippocampus is closely tied to spatial navigation, a central component in cognitive functioning, and critically involved in age-associated cognitive decline and dementia. This study evaluated a novel, cognitive computerized spatial navigation training (CSNT) program targeting the hippocampus, with expectation of mitigating possible cognitive decline with bed rest (BR). During a 14-day BR study with 16 healthy, older men (mean age = 60 ± 3, range = 55-65 years), half received CSNT for 12 days in 50-min sessions and half were controls (watching documentaries). This design uniquely controlled diet, sleep, and other personal and environmental activities. Although there were no cognitive declines in controls post-BR, CSNT participants demonstrated significant increases in executive/attention ability and processing speed, and continued spatial navigation testing showed improvement to 400 days post-BR. This intervention may prove useful to mitigate cognitive declines known to occur in long periods of immobilization and could have broader implications in protecting against age-related cognitive decline.

Age-Related Differences and Cognitive Correlates of Self-Reported and Direct Navigation Performance: The Effect of Real and Virtual Test Conditions Manipulation

The present study investigated the effect of aging on direct navigation measures and self-reported ones according to the real-virtual test manipulation. Navigation (wayfinding tasks) and spatial memory (paper-pencil tasks) performances, obtained either in real-world or in virtual-laboratory test conditions, were compared between young (n = 32) and older (n = 32) adults who had self-rated their everyday navigation behavior (SBSOD scale). Real age-related differences were observed in navigation tasks as well as in paper-pencil tasks, which investigated spatial learning relative to the distinction between survey-route knowledge. The manipulation of test conditions (real vs. virtual) did not change these age-related differences, which are mostly explained by age-related decline in both spatial abilities and executive functioning (measured with neuropsychological tests). In contrast, elderly adults did not differ from young adults in their self-reporting relative to everyday navigation, suggesting some underestimation of navigation difficulties by elderly adults. Also, spatial abilities in young participants had a mediating effect on the relations between actual and self-reported navigation performance, but not for older participants. So, it is assumed that the older adults carried out the navigation task with fewer available spatial abilities compared to young adults, resulting in inaccurate self-estimates.

Spatial navigation measured by the Floor Maze Test in patients with subjective cognitive impairment, mild cognitive impairment, and mild Alzheimer's disease

BACKGROUND

Impaired spatial navigation is an early sign of Alzheimer's disease (AD), but this can be difficult to assess in clinical practice. We examined how the performance on the Floor Maze Test (FMT), which combines navigation with walking, differed between patients with subjective cognitive impairment (SCI), mild cognitive impairment (MCI), and mild AD. We also explored if there was a significant relationship between the FMT and the cognitive tests or sociodemographic factors.

METHODS

The study included 128 patients from a memory clinic classified as having SCI (n = 19), MCI (n = 20), and mild AD (n = 89). Spatial navigation was assessed by having the patients walk through the FMT, a two-dimensional maze. Both timed measures and number of errors were recorded. Cognitive function was assessed by the Word List Memory test, the Clock Drawing test, the Trail Making tests (TMT) A and B, and the Mini Mental Status Examination (MMSE).

RESULTS

The patients with MCI were slower than those with SCI, while the patients with mild AD more frequently completed the FMT with errors or gave up than the patients with MCI. Performance on the FMT was significantly associated with executive function (measured by TMT-B).

CONCLUSIONS

The performances on the FMT worsened with increasing severity of cognitive impairment, and the FMT was primarily associated with executive function. The explained variance was relatively low, which may indicate that the standard cognitive test battery does not capture impairments of spatial navigation.

Age and active navigation effects on episodic memory: A virtual reality study

We investigated the navigation-related age effects on learning, proactive interference semantic clustering, recognition hits, and false recognitions in a naturalistic situation using a virtual apartment-based task. We also examined the neuropsychological correlates (executive functioning [EF] and episodic memory) of navigation-related age effects on memory. Younger and older adults either actively navigated or passively followed the computer-guided tour of an apartment. The results indicated that active navigation increased recognition hits compared with passive navigation, but it did not influence other memory measures (learning, proactive interference, and semantic clustering) to a similar extent in either age group. Furthermore, active navigation helped to reduce false recognitions in younger adults but increased those made by older adults. This differential effect of active navigation for younger and older adults was accounted for by EF score. Like for the subject-performed task effects, the effects from the navigation manipulation were well accounted for by item-specific/relational processing distinction, and they were also consistent with a source monitoring deficit in older adults.

Effects of enactment in episodic memory: a pilot virtual reality study with young and elderly adults

None of the previous studies on aging have tested the influence of action with respect to the degree of interaction with the environment (active or passive navigation) and the source of itinerary choice (self or externally imposed), on episodic memory (EM) encoding. The aim of this pilot study was to explore the influence of these factors on feature binding (the association between what, where, and when) in EM and on the subjective sense of remembering. Navigation in a virtual city was performed by 64 young and 64 older adults in one of four modes of exploration: (1) passive condition where participants were immersed as passengers of a virtual car [no interaction, no itinerary control (IC)], (2) IC (the subject chose the itinerary, but did not drive the car), (3) low, or (4) high navigation control (the subject just moved the car on rails or drove the car with a steering-wheel and a gas pedal on a fixed itinerary, respectively). The task was to memorize as many events encountered in the virtual environment as possible along with their factual (what), spatial (where), and temporal (when) details, and then to perform immediate and delayed memory tests. An age-related decline was evidenced for immediate and delayed feature binding. Compared to passive and high navigation conditions, and regardless of age-groups, feature binding was enhanced by low navigation and IC conditions. The subjective sense of remembering was boosted by the IC in older adults. Memory performance following high navigation was specifically linked to variability in executive functions. The present findings suggest that the decision of the itinerary is beneficial to boost EM in aging, although it does not eliminate age-related deficits. Active navigation can also enhance EM when it is not too demanding for subjects' cognitive resources.

Everyday-like memory for objects in ageing and Alzheimer's disease assessed in a visually complex environment: The role of executive functioning and episodic memory

To investigate everyday memory, more and more studies rely on virtual-reality applications to bridge the gap between in situ approaches and laboratory settings. In this vein, the present study was designed to assess everyday-like memory from the virtual reality-based Human Object Memory for Everyday Scenes (HOMES) test (Sauzéon et al., , Exp. Psychol., 59, 99) in ageing and in Alzheimer's disease (AD). Two aims motivated this study: the first was to assess multiple processes of episodic memory (EM) functioning embedded within contexts closely related to real life in ageing and AD using the multi-trial free-recall paradigm, and the second aim was to evaluate the mediating effects of executive functioning (EF), EM, and subjective memory complaints (SMCs) on age differences in the HOMES measures and in AD. To this end, the HOMES test and neurocognitive tests of EF and EM were administered to 23 younger adults, 23 older adults, and 16 patients with AD. The results were: firstly, compared to young adults, elderly adults presented only free-recall decline that almost disappeared in recognition condition whereas AD patients exhibited a poor clustering, learning, and recognition performance, and also a high amount of false recognition; secondly, age differences as well as AD related deficits on the HOMES test were mediated by both memory and EF measure while those observed on false memory indices were only mediated by EM measure; thirdly, the HOMES indices are related to SMCs even when episodic or EF measures are controlled. Overall, the results supported the fact that the VR-based memory test is an appropriate device to capture age-related differences as well as the AD effect with respect to both in situ and laboratory settings.

Everyday-like memory and its cognitive correlates in healthy older adults and in young patients with traumatic brain injury: a pilot study based on virtual reality

PURPOSE STATE: A pilot-study with a comparison approach between aging and traumatic brain injury (TBI) is proposed to investigate everyday object memory patterns using a virtual HOMES test.

METHODS

Sixteen young controls, 15 older adults and 15 TBI patients underwent the HOMES test and traditional tests.

RESULTS

Older adults and TBI patients exhibited similar HOMES performances: poor recall, a greater recognition benefit, high false recognitions, but intact clustering and proactive interference effects. The age-related differences for HOMES measures were mainly mediated by executive functioning, while the HOMES performances in the TBI group were correlated with memory measures.

CONCLUSION

The differential cognitive mediating effects for a similar everyday-like memory pattern are discussed by highlighting the need for more cautious interpretations of cognitive mechanisms behind similar behavioral patterns in different populations especially in clinical and rehabilitation settings.