Active and passive contributions to spatial learning

Knowing where to go: Spatial memory guides eye and body movements in a naturalistic visual search task

Most research on visual search has used simple tasks presented on a computer screen. However, in natural situations visual search almost always involves eye, head, and body movements in a three-dimensional (3D) environment. The different constraints imposed by these two types of search tasks might explain some of the discrepancies in our understanding concerning the use of memory resources and the role of contextual objects during search. To explore this issue, we analyzed a visual search task performed in an immersive virtual reality apartment. Participants searched for a series of geometric 3D objects while eye movements and head coordinates were recorded. Participants explored the apartment to locate target objects whose location and visibility were manipulated. For objects with reliable locations, we found that repeated searches led to a decrease in search time and number of fixations and to a reduction of errors. Searching for those objects that had been visible in previous trials but were only tested at the end of the experiment was also easier than finding objects for the first time, indicating incidental learning of context. More importantly, we found that body movements showed changes that reflected memory for target location: trajectories were shorter and movement velocities were higher, but only for those objects that had been searched for multiple times. We conclude that memory of 3D space and target location is a critical component of visual search and also modifies movement kinematics. In natural search, memory is used to optimize movement control and reduce energetic costs.

How Do In-Car Navigation Aids Impair Expert Navigators' Spatial Learning Ability?

Reliance on digital navigation aids has already shown negative impacts on navigators' innate spatial abilities. How this happens is still an open research question. We report on an empirical study with twenty-four experienced (male) taxi drivers to evaluate the long-term impacts of in-car navigation system use on the spatial learning ability of these navigation experts. Specifically, we measured cognitive load by means of electroencephalography (EEG) coupled with eye tracking to assess their visuospatial attention allocation during a video-based route-following task while driving through an unknown urban environment. We found that long-term reliance on in-car navigation aids did not affect participants' visual attention allocation during spatial learning but rather limited their ability to encode viewed geographic information into memory, which, in turn, led to greater cognitive load, especially along route segments between intersections. Participants with greater dependence on in-car navigation aids performed worse on the spatial knowledge tests. Our combined behavioral and neuropsychological findings provide evidence for the impairment of expert navigators' spatial learning ability when exposed to long-term use of digital in-car navigation aids.

Active and passive exploration for spatial knowledge acquisition: A meta-analysis

Literature reported mixed evidence on whether active exploration benefits spatial knowledge acquisition over passive exploration. Active spatial learning typically involves at least physical control of one's movement or navigation decision-making, while passive participants merely observe during exploration. To quantify the effects of active exploration in learning large-scale, unfamiliar environments, we analysed previous findings with the multi-level meta-analytical model. Potential moderators were identified and examined for their contributions to the variability in effect sizes. Of the 128 effect sizes retrieved from 33 experiments, we observed a small to moderate advantage of active exploration over passive observation. Important moderators include gender composition, decision-making, types of spatial knowledge, and matched visual information. We discussed the implications of the results along with the limitations.

The use of virtual reality as a perspective-taking manipulation to improve self-awareness in Alzheimer's disease

Lack of awareness of symptoms or having a condition referred to as anosognosia is a common feature of individuals with Alzheimer's Disease (AD). Previous literature on AD reported difficulties in evaluating self-abilities, often showing underestimation of limitations. There is increasing evidence that the perspective through which information is presented may moderate the performance appraisal and that anosognosia in AD might be a consequence of a deficit in assuming a third-person perspective. In this context, some studies showed that subjects may better recognize self-and other-difficulties when exposed to a third-person perspective. Considering the variety of approaches aiming to investigate the lack of awareness, there is still a scarcity of methods that provide great ecological validity and consider more than one facet of awareness, thus failing to offer more accurate evaluations of daily experiences. The present paper primarily addresses the theme of the multidimensional character of awareness of abilities in AD and the effect of perspective-taking on its trajectories. The focus turns to virtual reality as a promising tool for a greater evaluation of perspective-taking and self-awareness. Particularly, these systems offer the possibility to involve users in cognitive and sensorimotor tasks that simulate daily life conditions within immersive and realistic environments, and a great sense of embodiment. We propose that virtual reality might allow a great level of complexity, veracity, and safety that is needed for individuals with AD to behave according to their actual abilities and enable to explore the liaison between the subject's viewpoint, performance, and self-evaluation. In addition, we suggest promising clinical implications of virtual reality-based methods for individualized assessments, investigating specific impacts on subjects' life and possible improvements in their awareness.

Using a flashlight-contingent window paradigm to investigate visual search and object memory in virtual reality and on computer screens

A popular technique to modulate visual input during search is to use gaze-contingent windows. However, these are often rather discomforting, providing the impression of visual impairment. To counteract this, we asked participants in this study to search through illuminated as well as dark three-dimensional scenes using a more naturalistic flashlight with which they could illuminate the rooms. In a surprise incidental memory task, we tested the identities and locations of objects encountered during search. Importantly, we tested this study design in both immersive virtual reality (VR; Experiment 1) and on a desktop-computer screen (Experiment 2). As hypothesized, searching with a flashlight increased search difficulty and memory usage during search. We found a memory benefit for identities of distractors in the flashlight condition in VR but not in the computer screen experiment. Surprisingly, location memory was comparable across search conditions despite the enormous difference in visual input. Subtle differences across experiments only appeared in VR after accounting for previous recognition performance, hinting at a benefit of flashlight search in VR. Our findings highlight that removing visual information does not necessarily impair location memory, and that screen experiments using virtual environments can elicit the same major effects as VR setups.

Create your own path: social cerebellum in sequence-based self-guided navigation

Spatial trajectory planning and execution in a social context play a vital role in our daily lives. To study this process, participants completed a goal-directed task involving either observing a sequence of preferred goals and self-planning a trajectory (Self Sequencing) or observing and reproducing the entire trajectory taken by others (Other Sequencing). The results indicated that in the observation phase, witnessing entire trajectories created by others (Other Sequencing) recruited cerebellar mentalizing areas (Crus 2 and 1) and cortical mentalizing areas in the precuneus, ventral and dorsal medial prefrontal cortex and temporo-parietal junction more than merely observing several goals (Self Sequencing). In the production phase, generating a trajectory by oneself (Self Sequencing) activated Crus 1 more than merely reproducing the observed trajectories from others (Other Sequencing). Additionally, self-guided observation and planning (Self Sequencing) activated the cerebellar lobules IV and VIII more than Other Sequencing. Control conditions involving non-social objects and non-sequential conditions where the trajectory did not have to be (re)produced revealed no differences with the main Self and Other Sequencing conditions, suggesting limited social and sequential specificity. These findings provide insights into the neural mechanisms underlying trajectory observation and production by the self or others during social navigation.

Fixation-related potentials during mobile map assisted navigation in the real world: The effect of landmark visualization style

An often-proposed enhancement for mobile maps to aid assisted navigation is the presentation of landmark information, yet understanding of the manner in which they should be displayed is limited. In this study, we investigated whether the visualization of landmarks as 3D map symbols with either an abstract or realistic style influenced the subsequent processing of those landmarks during route navigation. We utilized a real-world mobile electroencephalography approach to this question by combining several tools developed to overcome the challenges typically encountered in real-world neuroscience research. We coregistered eye-movement and EEG recordings from 45 participants as they navigated through a real-world environment using a mobile map. Analyses of fixation event-related potentials revealed that the amplitude of the parietal P200 component was enhanced when participants fixated landmarks in the real world that were visualized on the mobile map in a realistic style, and that frontal P200 latencies were prolonged for landmarks depicted in either a realistic or abstract style compared with features of the environment that were not presented on the map, but only for the male participants. In contrast, we did not observe any significant effects of landmark visualization style on visual P1-N1 peaks or the parietal late positive component. Overall, the findings indicate that the cognitive matching process between landmarks seen in the environment and those previously seen on a map is facilitated by more realistic map display, while low-level perceptual processing of landmarks and recall of associated information are unaffected by map visualization style.

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.

Choice between decision-making strategies in human route-following

To follow a prescribed route, we must decide which way to turn at intersections. To do so, we can memorize either the serial order of directions or the associations between spatial cues and directions ("at the drug store, turn left"). Here, we investigate which of these two strategies is used if both are available. In Task S, all intersections looked exactly alike, and participants therefore had to use the serial order strategy to decide which way their route continued. In Task SA, each intersection displayed a unique spatial cue, and participants therefore could use either strategy. In Task A, each intersection displayed a unique cue, but the serial order of cues varied between trips, and participants therefore had to use the associative cue strategy. We found that route-following accuracy increased from trip to trip, was higher on routes with 12 rather than 18 intersections, and was higher on Task SA than on the other two tasks, both with 12 and with 18 intersections. Furthermore, participants on Task SA acquired substantial knowledge about the serial order of directions as well as about cue-direction associations, both with 12 and with 18 intersections. From this we conclude that, when both strategies were available, participants did not pick the better one but rather used both. This represents dual encoding, a phenomenon previously described for more elementary memory tasks. We further conclude that dual encoding may be implemented even if the memory load is not very high (i.e., even with only 12 intersections).

Investigating the different domains of environmental knowledge acquired from virtual navigation and their relationship to cognitive factors and wayfinding inclinations

When learning an environment from virtual navigation people gain knowledge about landmarks, their locations, and the paths that connect them. The present study newly aimed to investigate all these domains of knowledge and how cognitive factors such as visuospatial abilities and wayfinding inclinations might support virtual passive navigation. A total of 270 participants (145 women) were tested online. They: (i) completed visuospatial tasks and answered questionnaires on their wayfinding inclinations; and (ii) learnt a virtual path. The environmental knowledge they gained was assessed on their free recall of landmarks, their egocentric and allocentric pointing accuracy (location knowledge), and their performance in route direction and landmark location tasks (path knowledge). Visuospatial abilities and wayfinding inclinations emerged as two separate factors, and environmental knowledge as a single factor. The SEM model showed that both visuospatial abilities and wayfinding inclinations support the environmental knowledge factor, with similar pattern of relationships in men and women. Overall, factors related to the individual are relevant to the environmental knowledge gained from an online virtual passive navigation.

Spatial updating in virtual reality for reproducing object locations in vista space-Boundaries, landmarks, and idiothetic cues

Keeping track of locations across self-motion is possible by continuously updating spatial representations or by encoding and later instantaneously retrieving spatial representations. In virtual reality (VR), sensory cues to self-motion used in continuous updating are typically reduced. In passive translation compared to real walking in VR, optic flow is available but body-based (idiothetic) cues are missing. With both kinds of translation, boundaries and landmarks as static visual cues can be used for instantaneous updating. In two experiments, we let participants encode two target locations, one of which had to be reproduced by pointing after forward translation in immersive VR (HMD). We increased sensory cues to self-motion in comparison to passive translation either by strengthening optic flow or by real walking. Furthermore, we varied static visual cues in the form of boundaries and landmarks inside boundaries. Increased optic flow and real walking did not reliably increase performance suggesting that optic flow even in a sparse environment was sufficient for continuous updating or that merely instantaneous updating took place. Boundaries and landmarks, however, did support performance as quantified by decreased bias and increased precision, particularly if they were close to or even enclosed target locations. Thus, enriched spatial context is a viable method to support spatial updating in VR and synthetic environments (teleoperation). Spatial context does not only provide a static visual reference in offline updating and continuous allocentric self-location updating but also, according to recent neuroscientific evidence on egocentric bearing cells, contributes to continuous egocentric location updating as well.

Exploration patterns shape cognitive map learning

Spontaneous, volitional spatial exploration is crucial for building up a cognitive map of the environment. However, decades of research have primarily measured the fidelity of cognitive maps after discrete, controlled learning episodes. We know little about how cognitive maps are formed during naturalistic free exploration. Here, we investigated whether exploration trajectories predicted cognitive map accuracy, and how these patterns were shaped by environmental structure. In two experiments, participants freely explored a previously unfamiliar virtual environment. We related their exploration trajectories to a measure of how long they spent in areas with high global environmental connectivity (integration, as assessed by space syntax). In both experiments, we found that participants who spent more time on paths that offered opportunities for integration formed more accurate cognitive maps. Interestingly, we found no support for our pre-registered hypothesis that self-reported trait differences in navigation ability would mediate this relationship. Our findings suggest that exploration patterns predict cognitive map accuracy, even for people who self-report low ability, and highlight the importance of considering both environmental structure and individual variability in formal theory- and model-building.

A Study of Change Blindness in Immersive Environments

Human performance is poor at detecting certain changes in a scene, a phenomenon known as change blindness. Although the exact reasons of this effect are not yet completely understood, there is a consensus that it is due to our constrained attention and memory capacity: We create our own mental, structured representation of what surrounds us, but such representation is limited and imprecise. Previous efforts investigating this effect have focused on 2D images; however, there are significant differences regarding attention and memory between 2D images and the viewing conditions of daily life. In this work, we present a systematic study of change blindness using immersive 3D environments, which offer more natural viewing conditions closer to our daily visual experience. We devise two experiments; first, we focus on analyzing how different change properties (namely type, distance, complexity, and field of view) may affect change blindness. We then further explore its relation with the capacity of our visual working memory and conduct a second experiment analyzing the influence of the number of changes. Besides gaining a deeper understanding of the change blindness effect, our results may be leveraged in several VR applications such as redirected walking, games, or even studies on saliency or attention prediction.

Immersive medium for early clinical exposure - knowledge acquisition, spatial orientation and the unexpected role of annotation in 360° VR photos

AIM

360° VR photos could be a low-threshold possibility to increase early clinical exposure. Apart from granting insights into local routines and premises, the medium should facilitate knowledge acquisition and spatial orientation depending on its design. This assumption, however, is not yet substantiated empirically. Thus, three hypotheses were tested in consideration of Mayer's modality principle: 1) Providing 360° VR photos as visual reference improves retention and comprehension of information. 2) The annotation of text boxes in 360° VR photos compromises spatial orientation and presence. 3) Annotated audio commentary is superior to annotated text boxes in terms of cognitive load and knowledge acquisition.

METHODS

Using head-mounted displays, students of human (N=53) and dental medicine (N=8) completed one of three virtual tours through a surgical unit, which were created with 360° VR photos. In the first two variants, information about the facilities, medical devices and clinical procedures was annotated either as text boxes or audio commentary comprising 67 words on average (SD=6.67). In the third variant, the same information was given separately on a printed handout before the virtual tour. Taking user experience and individual learner characteristics into account, differences between conditions were measured regarding retention, comprehension, spatial orientation, cognitive load, and presence.

RESULTS

Concerning retention and comprehension of information, annotated text boxes outperformed annotated audio commentary and the handout condition. Although annotated audio commentary exhibited the lowest knowledge test scores, students preferred listening over reading. Students with an interest in VR and 360° media reported higher levels of enjoyment and presence. Regarding spatial orientation and presence, no significant group differences were found.

CONCLUSIONS

360° VR photos can convey information and a sense of spatial orientation effectively in the same learning scenario. For students, their use is both enjoyable and instructive. Unexpectedly, the ideal mode of annotation is not dictated by Mayer's modality principle. For information like in this study, annotated text boxes are better for knowledge acquisition than the subjectively preferred audio commentary. This finding is probably contingent on the length and the quality of the annotated text. To identify boundary conditions and to validate the findings, more research is required on the design and educational use of 360° VR photos.

Contribution of cognitive and bodily navigation cues to egocentric and allocentric spatial memory in hallucinations due to Parkinson's disease: A case report

Parkinson's disease (PD) manifestations can include visual hallucinations and illusions. Recent findings suggest that the coherent integration of bodily information within an egocentric representation could play a crucial role in these phenomena. Egocentric processing is a key aspect of spatial navigation and is supported by the striatum. Due to the deterioration of the striatal and motor systems, PD mainly impairs the egocentric rather than the allocentric spatial frame of reference. However, it is still unclear the interplay between spatial cognition and PD hallucinations and how different navigation mechanisms can influence such spatial frames of reference. We report the case of A.A., a patient that suffers from PD with frequent episodes of visual hallucinations and illusions. We used a virtual reality (VR) navigation task to assess egocentric and allocentric spatial memory under five navigation conditions (passive, immersive, map, path decision, and attentive cues) in A.A. and a PD control group without psychosis. In general, A.A. exhibited a statistically significant classical dissociation between the egocentric and allocentric performance with a greater deficit for the former. In particular, the dissociation was statistically significant in the "passive" and "attentive cues" conditions. Interestingly in the "immersive" condition, the dissociation was not significant and, in contrast to the other conditions, trends showed better performance for egocentric than allocentric memory. Within the theories of embodiment, we suggest that body-based information, as assessed with VR navigation tasks, could play an important role in PD hallucinations. In addition, the possible neural underpinnings and the usefulness of VR are discussed.

Combining egoformative and alloformative cues in a novel tabletop navigation task

Previous work has shown how different interfaces (i.e., route navigation, maps, or a combination of the two) influence spatial knowledge and recollection. To test for the existence of intermediate representations along an egocentric-to-allocentric continuum, we developed a novel task, tabletop navigation, to provide a mixture of cues that inform the emergence of egocentric and allocentric representations or strategies. In this novel tabletop task, participants navigated a remote-controlled avatar through a tabletop scale model of the virtual city. Participants learned virtual cities from either navigating routes, studying maps, or our new tabletop navigation task. We interleaved these learning tasks with either an in situ pointing task (the scene- and orientation-dependent pointing [SOP] task) or imagined judgements of relative direction (JRD) pointing. In Experiment 1, performance on each memory task was similar across learning tasks and performance on the route and map learning tasks correlated with more precise spatial recall on both the JRD and SOP tasks. Tabletop learning performance correlated with SOP performance only, suggesting a reliance on egocentric strategies, although increased utilization of the affordances of the tabletop task were related to JRD performance. In Experiment 2, using a modified criterion map learning task, participants who learned using maps provided more precise responses on the JRD compared to route or tabletop learning. Together, these findings provide mixed evidence for both optimization and egocentric predominance after learning from the novel tabletop navigation task.

Finding landmarks - An investigation of viewing behavior during spatial navigation in VR using a graph-theoretical analysis approach

Vision provides the most important sensory information for spatial navigation. Recent technical advances allow new options to conduct more naturalistic experiments in virtual reality (VR) while additionally gathering data of the viewing behavior with eye tracking investigations. Here, we propose a method that allows one to quantify characteristics of visual behavior by using graph-theoretical measures to abstract eye tracking data recorded in a 3D virtual urban environment. The analysis is based on eye tracking data of 20 participants, who freely explored the virtual city Seahaven for 90 minutes with an immersive VR headset with an inbuild eye tracker. To extract what participants looked at, we defined “gaze” events, from which we created gaze graphs. On these, we applied graph-theoretical measures to reveal the underlying structure of visual attention. Applying graph partitioning, we found that our virtual environment could be treated as one coherent city. To investigate the importance of houses in the city, we applied the node degree centrality measure. Our results revealed that 10 houses had a node degree that exceeded consistently two-sigma distance from the mean node degree of all other houses. The importance of these houses was supported by the hierarchy index, which showed a clear hierarchical structure of the gaze graphs. As these high node degree houses fulfilled several characteristics of landmarks, we named them “gaze-graph-defined landmarks”. Applying the rich club coefficient, we found that these gaze-graph-defined landmarks were preferentially connected to each other and that participants spend the majority of their experiment time in areas where at least two of those houses were visible. Our findings do not only provide new experimental evidence for the development of spatial knowledge, but also establish a new methodology to identify and assess the function of landmarks in spatial navigation based on eye tracking data.

The ability to navigate and orient ourselves in an unknown environment is important in everyday life. To better understand how we are able to learn about a new environment, it is important to study our behavior during the process of spatial navigation. New technical advances allow us to conduct studies in naturalistic virtual environments with participants wearing immersive VR-headsets. In addition, we can use eye trackers to observe the participant’s eye movements. This is interesting, because observing eye movements allows us to observe visual attention and, therefore, important cognitive processes. However, it can be difficult to analyze eye tracking data that was measured in a VR environment, as there is no established algorithm yet. Therefore, we propose a new method to analyze such eye tracking data. In addition, our method allows us to transform the eye tracking data into graphs which we can use to find new patterns in behavior that were not accessible before. Using this methodology, we found that participants who spend 90 min exploring a new virtual town, viewed some houses preferentially and we call them gaze-graph-defined landmarks. Our further analysis reveals also new characteristics of those houses that were not yet associated with landmarks.

Testing landmark-specific effects on route navigation in an ecologically valid setting: a simulated driving study

We used a driving simulator to investigate landmark-based route navigation in young adults. Previous research has examined how proximal and distal landmarks influence route navigation, however, these effects have not been extensively tested in ecologically-relevant settings. We used a virtual town in which participants learned various routes while simultaneously driving. We first examined the effect of four different landmark conditions on navigation performance, such that each driver experienced one of four versions of the town with either proximal landmarks only, distal landmarks only, both proximal and distal landmarks, or no landmarks. Drivers were given real-time navigation directions along a route to a target destination, and were then tested on their ability to navigate to the same destination without directions. We found that the presence of proximal landmarks significantly improved route navigation. We then examined the effect of prior exposure to proximal vs. distal landmarks by testing the same drivers in the same environment they previously encountered, but with the landmarks removed. In this case, we found that prior exposure to distal landmarks significantly improved route navigation. The present results are in line with existing research on route navigation and landmarks, suggesting that these findings can be extended to ecologically-relevant settings.

The syntheses of static and mobile wayfinding information: an empirical study of wayfinding preferences and behaviour in complex environments

Purpose

The efficient delivery of environmental information to wayfinders in complex environments is a challenge for information designers. Wayfinding tasks can be quite strenuous and frustrating in the visual absence of dedicated wayfinding information. This study aims to explore the behaviour regarding the use of wayfinding information by navigators in complex environments.

Design/methodology/approach

An experiment has been conducted in which participants have performed wayfinding tasks in a spatially complex university campus. The participants were instructed to use the think-aloud protocol during the experiment. The behaviour has been recorded using the head-mounted video recorder (GoPro), mobile phone screen (audio\video) recorder and interview. Twelve university students have been selected based on the equal level of spatial ability using the Santa Barbara Sense of Direction scale. Each participant performed three wayfinding tasks to locate the unknown locations inside the campus using a mobile wayfinding application and other information sources.

Findings

The results of this study demonstrated significant behavioural preferences in acquiring wayfinding information. Most of the participants synthesised the static and mobile wayfinding information sources, while some preferred only the static ones. Gender differences have also been found for planning and route finding. This study recommends the syntheses of static and mobile wayfinding information for designing an efficient institutional wayfinding system.

Research limitations/implications

The sample size has been kept small because of the qualitative exploration of the wayfinding behaviour regarding the wayfinding information syntheses behaviour. The experiment findings can be further explored with larger data set and controlled behavioural metrics. This study can help understand the user requirements in facilities management for spatially complex institutional environments.

Practical implications

The current findings can be further used to develop a framework for wayfinding information designers to assist them in understanding the current practices and incorporate them for improving institutional wayfinding systems. The management of the offered facilities within an institution can be further improved to make the space more efficient by saving users’ time and efforts.

Originality/value

Information syntheses or symbiosis of environmental information with the beacon-based digital wayfinding system is a new concept. This study explores the potential of such information syntheses for enhancing the legibility of complex institutional environments.

EXPRESS: "Run to the hills": Specific contributions of anticipated energy expenditure during active spatial learning

Grounded views of cognition consider that space perception is shaped by the body and its potential for action. These views are substantiated by observations such as the distance-on-hill effect, described as the overestimation of visually perceived uphill distances. An interpretation of this phenomenon is that slanted distances are overestimated because of the integration of energy expenditure cues. The visual perceptual processes involved are however usually tackled through explicit estimation tasks in passive situations. The goal of this study was to consider instead more ecological active spatial processing. Using immersive virtual reality and an omnidirectional treadmill, we investigated the effect of anticipated implicit physical locomotion cost by comparing spatial learning for uphill and downhill routes, while maintaining actual physical cost and walking speed constant. In the first experiment, participants learnt city layouts by exploring uphill or downhill routes. They were then tested using a landmark positioning task on a map. In the second experiment, the same protocol was used with participants who wore loaded ankle weights. Results from the first experiment showed that walking uphill routes led to a global underestimation of distances compared to downhill routes. This inverted distance-of-hill effect was not observed in the second experiment, where an additional effort was applied. These results suggest that the underestimation of distances observed in experiment one emerged from recalibration processes whose function was to solve the transgression of proprioceptive predictions linked with uphill energy expenditure. Results are discussed in relation to constructivist approaches on spatial representations and predictive coding theories.

Mother bats facilitate pup navigation learning

Learning where to forage and how to navigate to foraging sites are among the most essential skills that infants must acquire. How they do so is poorly understood. Numerous bat species carry their young in flight while foraging. This behavior is costly, and the benefits for the offspring are not fully clear. Using GPS tracking of both mothers and bat pups, we documented the pups' ontogeny from being non-volant to foraging independently. Our results suggest that mothers facilitate learning of navigation, assisting their pups with future foraging, by repeatedly placing them on specific trees and by behaving in a manner that seemed to encourage learning. Once independent, pups first flew alone to the same sites that they were carried to by their mothers, following similar routes used by their mothers, after which they began exploring new sites. Notably, in our observations, pups never independently followed their mothers in flight but were always carried by them, suggesting that learning occurred while passively being transported upside down.

Spatial learning correlates with decreased hippocampal activity in the goal-directed behavior of pigeons

Studies have suggested that the hippocampus (Hp) plays an important role in spatial learning and avian Hp is thought to have similar functions with mammals. However, the dynamic neural pattern of hippocampal activity is still unclear in the continuous spatial learning processes of birds. In this study, we recorded the behavioral data and local field potential (LFP) activity from Hp of pigeons performing goal-directed behavior. Then the spectral properties and time-frequency properties of the LFPs are analyzed, comparing with the behavioral changes during spatial learning. The results indicated that the power of the LFP signal in the gamma band shown decreasing trend during spatial learning. Time-frequency analysis results shown that the hippocampal gamma activity was weakened along with the learning process. The results indicate that spatial learning correlated with the decreased gamma activity in Hp and hippocampal neural patterns of pigeons were modulated by goal-directed behavior.

Spatial knowledge acquired from first-person and dynamic map perspectives

As we become familiar with an environment through navigation and map study, spatial information is encoded into a mental representation of space. It is currently unclear to what degree mental representations of space are determined by the perspective in which spatial information is acquired. The overlapping model of spatial knowledge argues that spatial information is encoded into a common spatial representation independent of learning perspective, whereas the partially independent model argues for dissociated spatial representations specific to the learning perspective. The goal of this study was to provide insight into this debate by investigating the cognitive functions underlying the formation of spatial knowledge obtained through different learning perspectives. Hundred participants studied an ecologically valid virtual environment via a first-person and map perspective. The map employed in the study was dynamic, allowing for the disentanglement of learning perspective and sequential information presentation. Spatial knowledge was examined using an array of navigation tasks that assessed both route and survey knowledge. Results show that distinct visuospatial abilities predict route knowledge depending on whether an environment is learned via a first-person or map perspective. Both shared and distinct visuospatial abilities predicted the formation of survey knowledge in the two perspective learning conditions. Additionally, sequential presentation of map information diminishes the perspective dependent performance differences on spatial tasks reported in earlier studies. Overall, the results provide further evidence for the partially dissociated model of spatial knowledge, as the perspective from which an environment is learned influences the spatial representation that is formed.

Building Embodied Spaces for Spatial Memory Neurorehabilitation with Virtual Reality in Normal and Pathological Aging

Along with deficits in spatial cognition, a decline in body-related information is observed in aging and is thought to contribute to impairments in navigation, memory, and space perception. According to the embodied cognition theories, bodily and environmental information play a crucial role in defining cognitive representations. Thanks to the possibility to involve body-related information, manipulate environmental stimuli, and add multisensory cues, virtual reality is one of the best candidates for spatial memory rehabilitation in aging for its embodied potential. However, current virtual neurorehabilitation solutions for aging and neurodegenerative diseases are in their infancy. Here, we discuss three concepts that could be used to improve embodied representations of the space with virtual reality. The virtual bodily representation is the combination of idiothetic information involved during virtual navigation thanks to input/output devices; the spatial affordances are environmental or symbolic elements used by the individual to act in the virtual environment; finally, the virtual enactment effect is the enhancement on spatial memory provided by actively (cognitively and/or bodily) interacting with the virtual space and its elements. Theoretical and empirical findings will be presented to propose innovative rehabilitative solutions in aging for spatial memory and navigation.

A neural code for egocentric spatial maps in the human medial temporal lobe

Spatial navigation and memory rely on neural systems that encode places, distances, and directions in relation to the external world or relative to the navigating organism. Place, grid, and head-direction cells form key units of world-referenced, allocentric cognitive maps, but the neural basis of self-centered, egocentric representations remains poorly understood. Here, we used human single-neuron recordings during virtual spatial navigation tasks to identify neurons providing a neural code for egocentric spatial maps in the human brain. Consistent with previous observations in rodents, these neurons represented egocentric bearings toward reference points positioned throughout the environment. Egocentric bearing cells were abundant in the parahippocampal cortex and supported vectorial representations of egocentric space by also encoding distances toward reference points. Beyond navigation, the observed neurons showed activity increases during spatial and episodic memory recall, suggesting that egocentric bearing cells are not only relevant for navigation but also play a role in human memory.

Vestibular cues improve landmark-based route navigation: A simulated driving study

It is well established that humans use self-motion and landmark cues to successfully navigate their environment. Existing research has demonstrated a critical role of the vestibular system in supporting navigation across many species. However, less is known about how vestibular cues interact with landmarks to promote successful navigation in humans. In the present study, we used a motion simulator to manipulate the presence or absence of vestibular cues during a virtual navigation task. Participants learned routes to a target destination in three different landmark blocks in a virtual town: one with proximal landmarks, one with distal landmarks, and one with no landmarks present. Afterwards, they were tested on their ability to retrace the route and find the target destination. We observed a significant interaction between vestibular cues and proximal landmarks, demonstrating that the potential for vestibular cues to improve route navigation is dependent on landmarks that are present in the environment. In particular, vestibular cues significantly improved route navigation when proximal landmarks were present, but this was not significant when distal landmarks or no landmarks were present. Overall, our results indicate that landmarks play an important role in the successful incorporation of vestibular cues to human spatial navigation.

The effect of navigation method and visual display on distance perception in a large-scale virtual building

Immersive virtual reality (VR) technology has become a popular method for fundamental and applied spatial cognition research. One challenge researchers face is emulating walking in a large-scale virtual space although the user is in fact in a small physical space. To address this, a variety of movement interfaces in VR have been proposed, from traditional joysticks to teleportation and omnidirectional treadmills. These movement methods tap into different mental processes of spatial learning during navigation, but their impacts on distance perception remain unclear. In this paper, we investigated the role of visual display, proprioception, and optic flow on distance perception in a large-scale building by manipulating four different movement methods. Eighty participants either walked in a real building, or moved through its virtual replica using one of three movement methods: VR-treadmill, VR-touchpad, and VR-teleportation. Results revealed that, first, visual display played a major role in both perceived and traversed distance estimates but did not impact environmental distance estimates. Second, proprioception and optic flow did not impact the overall accuracy of distance perception, but having only an intermittent optic flow (in the VR-teleportation movement method) impaired the precision of traversed distance estimates. In conclusion, movement method plays a significant role in distance perception but does not impact the configurational knowledge learned in a large-scale real and virtual building, and the VR-touchpad movement method provides an effective interface for navigation in VR.

How can basic research on spatial cognition enhance the visual accessibility of architecture for people with low vision?

People with visual impairment often rely on their residual vision when interacting with their spatial environments. The goal of visual accessibility is to design spaces that allow for safe travel for the large and growing population of people who have uncorrectable vision loss, enabling full participation in modern society. This paper defines the functional challenges in perception and spatial cognition with restricted visual information and reviews a body of empirical work on low vision perception of spaces on both local and global navigational scales. We evaluate how the results of this work can provide insights into the complex problem that architects face in the design of visually accessible spaces.

Egocentric and Allocentric Spatial Memory in Mild Cognitive Impairment with Real-World and Virtual Navigation Tasks: A Systematic Review

BACKGROUND

Spatial navigation is the ability to estimate one's position on the basis of environmental and self-motion cues. Spatial memory is the cognitive substrate underlying navigation and relies on two different reference frames: egocentric and allocentric. These spatial frames are prone to decline with aging and impairment is even more pronounced in Alzheimer's disease (AD) or in mild cognitive impairment (MCI).

OBJECTIVE

To conduct a systematic review of experimental studies investigating which MCI population and tasks are used to evaluate spatial memory and how allocentric and egocentric deficits are impaired in MCI after navigation.

METHODS

PRISMA and PICO guidelines were applied to carry out the systematic search. Down and Black checklist was used to assess methodological quality.

RESULTS

Our results showed that amnestic MCI and AD pathology are the most investigated typologies; both egocentric and allocentric memory are impaired in MCI individuals, and MCI due to AD biomarkers has specific encoding and retrieval impairments; secondly, spatial navigation is principally investigated with the hidden goal task (virtual and real-world version), and among studies involving virtual reality, the privileged setting consists of non-immersive technology; thirdly, despite subtle differences, real-world and virtual versions showed good overlap for the assessment of MCI spatial memory.

CONCLUSION

Considering that MCI is a subclinical entity with potential risk for conversion to dementia, investigating spatial memory deficits with navigation tasks might be crucial to make accurate diagnosis and rehabilitation.

An Important Step toward Understanding the Role of Body-based Cues on Human Spatial Memory for Large-Scale Environments

Moving our body through space is fundamental to human navigation; however, technical and physical limitations have hindered our ability to study the role of these body-based cues experimentally. We recently designed an experiment using novel immersive virtual-reality technology, which allowed us to tightly control the availability of body-based cues to determine how these cues influence human spatial memory [Huffman, D. J., & Ekstrom, A. D. A modality-independent network underlies the retrieval of large-scale spatial environments in the human brain. Neuron, 104, 611-622, 2019]. Our analysis of behavior and fMRI data revealed a similar pattern of results across a range of body-based cues conditions, thus suggesting that participants likely relied primarily on vision to form and retrieve abstract, holistic representations of the large-scale environments in our experiment. We ended our paper by discussing a number of caveats and future directions for research on the role of body-based cues in human spatial memory. Here, we reiterate and expand on this discussion, and we use a commentary in this issue by A. Steel, C. E. Robertson, and J. S. Taube (Current promises and limitations of combined virtual reality and functional magnetic resonance imaging research in humans: A commentary on Huffman and Ekstrom (2019). Journal of Cognitive Neuroscience, 2020) as a helpful discussion point regarding some of the questions that we think will be the most interesting in the coming years. We highlight the exciting possibility of taking a more naturalistic approach to study the behavior, cognition, and neuroscience of navigation. Moreover, we share the hope that researchers who study navigation in humans and nonhuman animals will synergize to provide more rapid advancements in our understanding of cognition and the brain.

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.

Using virtual reality to assess dynamic self-motion and landmark cues for spatial updating in children and adults

The relative contribution of different sources of information for spatial updating - keeping track of one's position in an environment - has been highly debated. Further, children and adults may differ in their reliance on visual versus body-based information for spatial updating. In two experiments, we tested children (age 10-12 years) and young adult participants on a virtual point-to-origin task that varied the types of self-motion information available for translation: full-dynamic (walking), visual-dynamic (controller induced), and no-dynamic (teleporting). In Experiment 1, participants completed the three conditions in an indoor virtual environment with visual landmark cues. Adults were more accurate in the full- and visual-dynamic conditions (which did not differ from each other) compared to the no-dynamic condition. In contrast, children were most accurate in the visual-dynamic condition and also least accurate in the no-dynamic condition. Adults outperformed children in all conditions. In Experiment 2, we removed the potential for relying on visual landmarks by running the same paradigm in an outdoor virtual environment with no geometrical room cues. As expected, adults' errors increased in all conditions, but performance was still relatively worse in teleporting. Surprisingly, children showed overall similar accuracy and patterns across locomotion conditions to adults. Together, the results support the importance of dynamic translation information (either visual or body-based) for spatial updating across both age groups, but suggest children may be more reliant on visual information than adults.

Is the construction of spatial models multimodal? New evidences towards sensory-motor information involvement from temporary blindness study

Using new developments of interference paradigm, this paper addresses the raising question of the involvement of sensory-motor information in the construction of elaborate spatial models (Johnson-Laird in Mental models: towards a cognitive science of language, inference, and consciousness Cambridge University Press Cambridge, 1983). In two experiments, 112 participants had to explore and memorize the spatial arrangement of 12 objects, disposed on 3 tables. Participants were either sighted or blindfolded, leading to a visual or a more sensory-motor based exploration of the room. During exploration, participants were required to perform a classical verbal, a visuo-spatial dual task or none. In the second experiment, more exploratory, we draw on interference paradigm literature and its recent development in the embodied field to develop two original dual tasks meant to interfere directly with the acquisition of sensory-motor information (haptic and action). After this learning phase, five tasks addressing spatial memory and reasoning used in the construction of spatial models were performed. Results showed classical effects for both verbal and visuo-spatial tasks for sighted participants, but not for blindfolded sighted ones, suggesting that a temporary visual deprivation led participants to use other way to build their spatial models. Our second experiment confirmed this point by showing effect of both sensory-motor dual tasks, especially for blindfolded sighted participants. Taking together, our results support a multimodal view of spatial models, and that exploration modality will influence the information used to construct them. Moreover, this challenges the Baddeley's dualist view of working memory as a reference to theorize the construction of spatial models and provide new experimental evidences towards an embodied view of spatial models.

"Walk this way": specific contributions of active walking to the encoding of metric properties during spatial learning

The effect of body-based information on spatial memory has been traditionally described as a facilitating factor for large-scale spatial learning in the field of active learning research (Chrastil & Warren, Psychonomic Bulletin and Review, 19(1):1-23; 2012). The specific contribution of body-based information to spatial representation properties is however not yet well defined and the mechanisms through which body-based information contributes to spatial learning are not clear enough. To disambiguate the effect of active spatial learning on the quality of spatial representations from the beneficial effect of physiological arousal, we compared four experimental conditions (walking on a unidirectional treadmill during learning, retrieval, both phases or no walking). Results showed no effect of the walking condition for a route perspective task, but a significant effect on a survey perspective task (landmark positioning on a map): participants who walked during encoding (encoding group and encoding + retrieval group) obtained better results than those who did not walk or walked only during retrieval. Geometrical analysis of spatial positions on maps revealed that the activity of walking during encoding improves the correlation between participants' coordinates and actual coordinates through better distance estimations and angular accuracy, even though the optic flow was not matched with individual walking speed. Control group variance in all measures was higher than that of the walking groups (regardless of the moment of walking). Taken together, these results provide arguments for the multimodal nature of spatial representations, where body-related information derived from walking is involved in metric properties accuracy and perspective switching.

A comparison of virtual locomotion methods in movement experts and non-experts: testing the contributions of body-based and visual translation for spatial updating

Both visual and body-based (vestibular and proprioceptive) information contribute to spatial updating, or the way a navigator keeps track of self-position during movement. Research has tested the relative contributions of these sources of information and found mixed results, with some studies demonstrating the importance of body-based information, especially for translation, and some demonstrating the sufficiency of visual information. Here, we invoke an individual differences approach to test whether some individuals may be more dependent on certain types of information compared to others. Movement experts tend to be dependent on motor processes in small-scale spatial tasks, which can help or hurt performance, but it is unknown if this effect extends into large-scale spatial tasks like spatial updating. In the current study, expert dancers and non-dancers completed a virtual reality point-to-origin task with three locomotion methods that varied the availability of body-based and visual information for translation: walking, joystick, and teleporting. We predicted decrements in performance in both groups as self-motion information was reduced, and that dancers would show a larger cost. Surprisingly, both dancers and non-dancers performed with equal accuracy in walking and joystick and were impaired in teleporting, with no large differences between groups. We found slower response times for both groups with reductions in self-motion information, and minimal evidence for a larger cost for dancers. While we did not see strong dance effects, more participation in spatial activities related to decreased angular error. Together, the results suggest a flexibility in reliance on visual or body-based information for translation in spatial updating that generalizes across dancers and non-dancers, but significant decrements associated with removing both of these sources of information.

Impact of Learning Methods on Spatial Knowledge Acquisition

Research on the acquisition of spatial knowledge not only enriches our understanding of the theory of spatial knowledge representation but also creates practical value for the application of spatial knowledge. The aim of this study is to understand the impact of different learning methods on the acquisition of spatial knowledge, including the role of 2D maps, the difference between physical interaction and virtual interaction, and whether passive learning can replace active learning in virtual environments. One experiment was conducted, in which landmark knowledge and configurational knowledge were measured. Results indicate that 2D maps play a supporting role in acquiring both landmark knowledge and configurational knowledge. In addition, physical learning was associated with better spatial knowledge representation compared with virtual learning. An analysis of observational data in the third comparison found no significant difference between passive learning and active learning using virtual street view maps. However, with high-quality learning materials, passive learning can contribute to the acquisition of spatial knowledge more efficiently than active learning.

Scene Transitions and Teleportation in Virtual Reality and the Implications for Spatial Awareness and Sickness

Various viewing and travel techniques are used in immersive virtual reality to allow users to see different areas or perspectives of 3D environments. Our research evaluates techniques for visually showing transitions between two viewpoints in head-tracked virtual reality. We present four experiments that focus on automated viewpoint changes that are controlled by the system rather than by interactive user control. The experiments evaluate three different transition techniques (teleportation, animated interpolation, and pulsed interpolation), different types of visual adjustments for each technique, and different types of viewpoint changes. We evaluated how differences in transition can influence a viewer's comfort, sickness, and ability to maintain spatial awareness of dynamic objects in a virtual scene. For instant teleportations, the experiments found participants could most easily track scene changes with rotational transitions without translational movements. Among the tested techniques, animated interpolations allowed significantly better spatial awareness of moving objects, but the animated technique was also rated worst in terms of sickness, particularly for rotational viewpoint changes. Across techniques, viewpoint transitions involving both translational and rotational changes together were more difficult to track than either individual type of change.

Does active learning benefit spatial memory during navigation with restricted peripheral field?

Spatial learning of real-world environments is impaired with severely restricted peripheral field of view (FOV). In prior research, the effects of restricted FOV on spatial learning have been studied using passive learning paradigms - learners walk along pre-defined paths and are told the location of targets to be remembered. Our research has shown that mobility demands and environmental complexity may contribute to impaired spatial learning with restricted FOV through attentional mechanisms. Here, we examine the role of active navigation, both in locomotion and in target search. First, we compared effects of active versus passive locomotion (walking with a physical guide versus being pushed in a wheelchair) on a task of pointing to remembered targets in participants with simulated 10° FOV. We found similar performance between active and passive locomotion conditions in both simpler (Experiment 1) and more complex (Experiment 2) spatial learning tasks. Experiment 3 required active search for named targets to remember while navigating, using both a mild and a severe FOV restriction. We observed no difference in pointing accuracy between the two FOV restrictions but an increase in attentional demands with severely restricted FOV. Experiment 4 compared active and passive search with severe FOV restriction, within subjects. We found no difference in pointing accuracy, but observed an increase in cognitive load in active versus passive search. Taken together, in the context of navigating with restricted FOV, neither locomotion method nor level of active search affected spatial learning. However, the greater cognitive demands could have counteracted the potential advantage of the active learning conditions.

Where are we going and where have we been? Examining the effects of maps on spatial learning in an indoor guided navigation task

BACKGROUND

International Atomic Energy Agency (IAEA) safeguards inspectors are faced with the difficult task of learning the layout of complex nuclear facilities while being escorted through the facilities. This study addresses a gap in the literature regarding how to best support the development of inspectors' spatial knowledge, given the constraint that they cannot bring digital devices into most nuclear facilities. We tested whether viewing a map before learning a guided route or carrying a map along the route enabled better spatial learning than having no exposure to a map. Moreover, we tested the impact of carrying maps with different levels of detail (simple 2D, simple 3D, or complex 2D maps) on spatial learning outcomes, as well as interactions between map type and individual differences in sense of direction.

RESULTS

The results showed nearly opposite patterns of performance for participants with good and poor sense of direction scores. Participants with a good sense of direction showed higher levels of spatial knowledge when studying or carrying simple maps, whether 2D or 3D, but they did not benefit from using a complex map. Participants with a poor sense of direction showed lower levels of spatial knowledge when using a simple map relative to using no map or a complex map, suggesting that they did not attempt to use the complex map. For both groups of participants, referring to a simple map while learning a route decreased their awareness of their environment, as measured by response times on a memory test that included incidentally learned items.

Testing Navigation in Real Space: Contributions to Understanding the Physiology and Pathology of Human Navigation Control

Successful navigation relies on the flexible and appropriate use of metric representations of space or topological knowledge of the environment. Spatial dimensions (2D vs. 3D), spatial scales (vista-scale vs. large-scale environments) and the abundance of visual landmarks critically affect navigation performance and behavior in healthy human subjects. Virtual reality (VR)-based navigation paradigms in stationary position have given insight into the major navigational strategies, namely egocentric (body-centered) and allocentric (world-centered), and the cerebral control of navigation. However, VR approaches are biased towards optic flow and visual landmark processing. This major limitation can be overcome to some extent by increasingly immersive and realistic VR set-ups (including large-screen projections, eye tracking and use of head-mounted camera systems). However, the highly immersive VR settings are difficult to apply particularly to older subjects and patients with neurological disorders because of cybersickness and difficulties with learning and conducting the tasks. Therefore, a need for the development of novel spatial tasks in real space exists, which allows a synchronous analysis of navigational behavior, strategy, visual explorations and navigation-induced brain activation patterns. This review summarizes recent findings from real space navigation studies in healthy subjects and patients with different cognitive and sensory neurological disorders. Advantages and limitations of real space navigation testing and different VR-based navigation paradigms are discussed in view of potential future applications in clinical neurology.

Neurorehabilitation of Spatial Memory Using Virtual Environments: A Systematic Review

In recent years, virtual reality (VR) technologies have become widely used in clinical settings because they offer impressive opportunities for neurorehabilitation of different cognitive deficits. Specifically, virtual environments (VEs) have ideal characteristics for navigational training aimed at rehabilitating spatial memory. A systematic search, following PRISMA guidelines, was carried out to explore the current scenario in neurorehabilitation of spatial memory using virtual reality. The literature on this topic was queried, 5048 papers were screened, and 16 studies were included, covering patients presenting different neuropsychological diseases. Our findings highlight the potential of the navigational task in virtual environments (VEs) for enhancing navigation and orientation abilities in patients with spatial memory disorders. The results are promising and suggest that VR training can facilitate neurorehabilitation, promoting brain plasticity processes. An overview of how VR-based training has been implemented is crucial for using these tools in clinical settings. Hence, in the current manuscript, we have critically debated the structure and the length of training protocols, as well as a different type of exploration through VR devices with different degrees of immersion. Furthermore, we analyzed and highlighted the crucial role played by the selection of the assessment tools.

A Modality-Independent Network Underlies the Retrieval of Large-Scale Spatial Environments in the Human Brain

In humans, the extent to which body-based cues, such as vestibular, somatosensory, and motoric cues, are necessary for normal expression of spatial representations remains unclear. Recent breakthroughs in immersive virtual reality technology allowed us to test how body-based cues influence spatial representations of large-scale environments in humans. Specifically, we manipulated the availability of body-based cues during navigation using an omnidirectional treadmill and a head-mounted display, investigating brain differences in levels of activation (i.e., univariate analysis), patterns of activity (i.e., multivariate pattern analysis), and putative network interactions between spatial retrieval tasks using fMRI. Our behavioral and neuroimaging results support the idea that there is a core, modality-independent network supporting spatial memory retrieval in the human brain. Thus, for well-learned spatial environments, at least in humans, primarily visual input may be sufficient for expression of complex representations of spatial environments. VIDEO ABSTRACT.

Real-Life Neuroscience: An Ecological Approach to Brain and Behavior Research

Owing to advances in neuroimaging technology, the past couple of decades have witnessed a surge of research on brain mechanisms that underlie human cognition. Despite the immense development in cognitive neuroscience, the vast majority of neuroimaging experiments examine isolated agents carrying out artificial tasks in sensory and socially deprived environments. Thus, the understanding of the mechanisms of various domains in cognitive neuroscience, including social cognition and episodic memory, is sorely lacking. Here we focus on social and memory research as representatives of cognitive functions and propose that mainstream, lab-based experimental designs in these fields suffer from two fundamental limitations, pertaining to person-dependent and situation-dependent factors. The person-dependent factor addresses the issue of limiting the active role of the participants in lab-based paradigms that may interfere with their sense of agency and embodiment. The situation-dependent factor addresses the issue of the artificial decontextualized environment in most available paradigms. Building on recent findings showing that real-life as opposed to controlled experimental paradigms involve different mechanisms, we argue that adopting a real-life approach may radically change our understanding of brain and behavior. Therefore, we advocate in favor of a paradigm shift toward a nonreductionist approach, exploiting portable technology in semicontrolled environments, to explore behavior in real life.

A serious game to explore human foraging in a 3D environment

Traditional search tasks have taught us much about vision and attention. Recently, several groups have begun to use multiple-target search to explore more complex and temporally extended "foraging" behaviour. Many of these new foraging tasks, however, maintain the simplified 2D displays and response demands associated with traditional, single-target visual search. In this respect, they may fail to capture important aspects of real-world search or foraging behaviour. In the current paper, we present a serious game for mobile platforms, developed in Unity3D, in which human participants play the role of an animal foraging for food in a simulated 3D environment. Game settings can be adjusted, so that, for example, custom target and distractor items can be uploaded, and task parameters, such as the number of target categories or target/distractor ratio are all easy to modify. We are also making the Unity3D project available, so that further modifications can also be made. We demonstrate how the app can be used to address specific research questions by conducting two human foraging experiments. Our results indicate that in this 3D environment, a standard feature/conjunction manipulation does not lead to a reduction in foraging runs, as it is known to do in simple, 2D foraging tasks.