Do humans integrate routes into a cognitive map? Map- versus landmark-based navigation of novel shortcuts

How spatial-cue reliability affects navigational performance in young and older adults

Navigational abilities decline with age, but the cognitive underpinnings of this cognitive decline remain partially understood. Navigation is guided by landmarks and self-motion cues, that we address when estimating our location. These sources of spatial information are often associated with noise and uncertainty, thus posing a challenge during navigation. To overcome this challenge, humans and other species rely on navigational cues according to their reliability: reliable cues are highly weighted and therefore strongly influence our spatial behavior, compared to less reliable ones. We hypothesize that older adults do not efficiently weigh spatial cues, and accordingly, the reliability levels of navigational cues may not modulate their spatial behavior, as with younger adults. To test this, younger and older adults performed a virtual navigational task, subject to modified reliability of landmarks and self-motion cues. The findings revealed that while increased reliability of spatial cues improved navigational performance across both age groups, older adults exhibited diminished sensitivity to changes in landmark reliability. The findings demonstrate a cognitive mechanism that could lead to impaired navigation abilities in older adults.

Human navigation strategies and their errors result from dynamic interactions of spatial uncertainties

Goal-directed navigation requires continuously integrating uncertain self-motion and landmark cues into an internal sense of location and direction, concurrently planning future paths, and sequentially executing motor actions. Here, we provide a unified account of these processes with a computational model of probabilistic path planning in the framework of optimal feedback control under uncertainty. This model gives rise to diverse human navigational strategies previously believed to be distinct behaviors and predicts quantitatively both the errors and the variability of navigation across numerous experiments. This furthermore explains how sequential egocentric landmark observations form an uncertain allocentric cognitive map, how this internal map is used both in route planning and during execution of movements, and reconciles seemingly contradictory results about cue-integration behavior in navigation. Taken together, the present work provides a parsimonious explanation of how patterns of human goal-directed navigation behavior arise from the continuous and dynamic interactions of spatial uncertainties in perception, cognition, and action.

Spatial and Temporal Hierarchy for Autonomous Navigation Using Active Inference in Minigrid Environment

Robust evidence suggests that humans explore their environment using a combination of topological landmarks and coarse-grained path integration. This approach relies on identifiable environmental features (topological landmarks) in tandem with estimations of distance and direction (coarse-grained path integration) to construct cognitive maps of the surroundings. This cognitive map is believed to exhibit a hierarchical structure, allowing efficient planning when solving complex navigation tasks. Inspired by human behaviour, this paper presents a scalable hierarchical active inference model for autonomous navigation, exploration, and goal-oriented behaviour. The model uses visual observation and motion perception to combine curiosity-driven exploration with goal-oriented behaviour. Motion is planned using different levels of reasoning, i.e., from context to place to motion. This allows for efficient navigation in new spaces and rapid progress toward a target. By incorporating these human navigational strategies and their hierarchical representation of the environment, this model proposes a new solution for autonomous navigation and exploration. The approach is validated through simulations in a mini-grid environment.

Path integration, rather than being suppressed, is used to update spatial views in familiar environments with constantly available landmarks

This project tested three hypotheses conceptualizing the interaction between path integration based on self-motion and piloting based on landmarks in a familiar environment with persistent landmarks. The first hypothesis posits that path integration functions automatically, as in environments lacking persistent landmarks (environment-independent hypothesis). The second hypothesis suggests that persistent landmarks suppress path integration (suppression hypothesis). The third hypothesis proposes that path integration updates the spatial views of the environment (updating-spatial-views hypothesis). Participants learned a specific object's location. Subsequently, they undertook an outbound path originating from the object and then indicated the object's location (homing). In Experiments 1&1b, there were landmarks throughout the first 9 trials. On some later trials, the landmarks were presented during the outbound path but unexpectedly removed during homing (catch trials). On the last trials, there were no landmarks throughout (baseline trials). Experiments 2-3 were similar but added two identical objects (the original one and a rotated distractor) during homing on the catch and baseline trials. Experiment 4 replaced two identical objects with two groups of landmarks. The results showed that in Experiments 1&1b, homing angular error on the first catch trial was significantly larger than the matched baseline trial, undermining the environment-independent hypothesis. Conversely, in Experiment 2-4, the proportion of participants who recognized the original object or landmarks was similar between the first catch and the matched baseline trial, favoring the updating-spatial-views hypothesis over the suppression hypothesis. Therefore, while mismatches between updated spatial views and actual views of unexpected removal of landmarks impair homing performance, the updated spatial views help eliminate ambiguous targets or landmarks within the familiar environment.

Cognitive-Cultural Looping Mechanism of Urban Space Conceptualization

A crucial point for urban design is the acknowledgement that urban material structures are not only constituting a set of cognitive-cultural affordances that shapes people's behavior and experiential world, but likewise that the design process itself is an expression of cultural conceptualizations possibly evoked by ongoing cultural practices and perceptions, thus forming a dynamic loop. In this paper, we outline a framework for the study of material, cultural and social mechanisms interacting with human cognition, behavior and emotions. We attempt a conceptual model that integrates dynamic interactions between cognitive-cultural affordances and our conceptualization of the environment and provides a few illustrative case examples. The model proposes a set of dynamic relations between cognitive and cultural processes at shorter time scales modifying conceptualizations and environmental affordances on longer timescales, while these - in turn - come to guide and constrain processes at the shorter timescales. The model has important implications for our understanding of the role of environmental design, especially urban design, as bridging between aspects of human situated experience, behavior, social and cultural norms and material culture.

Measuring configural spatial knowledge: Individual differences in correlations between pointing and shortcutting

People use environmental knowledge to maintain a sense of direction in daily life. This knowledge is typically measured by having people point to unseen locations (judgments of relative direction) or navigate efficiently in the environment (shortcutting). Some people can estimate directions precisely, while others point randomly. Similarly, some people take shortcuts not experienced during learning, while others mainly follow learned paths. Notably, few studies have directly tested the correlation between pointing and shortcutting performance. We compared pointing and shortcutting in two experiments, one using desktop virtual reality (VR) (N = 57) and one using immersive VR (N = 48). Participants learned a new environment by following a fixed route and were then asked to point to unseen locations and navigate to targets by the shortest path. Participants' performance was clustered into two groups using K-means clustering. One (lower ability) group pointed randomly and showed low internal consistency across trials in pointing, but were able to find efficient routes, and their pointing and efficiency scores were not correlated. The others (higher ability) pointed precisely, navigated by efficient routes, and their pointing and efficiency scores were correlated. These results suggest that with the same egocentric learning experience, the correlation between pointing and shortcutting depends on participants' learning ability, and internal consistency and discriminating power of the measures. Inconsistency and limited discriminating power can lead to low correlations and mask factors driving human variation. Psychometric properties, largely under-reported in spatial cognition, can advance our understanding of individual differences and cognitive processes for complex spatial tasks.

Cognitive map formation in the blind is enhanced by three-dimensional tactile information

For blind individuals, tactile maps are useful tools to form cognitive maps through touch. However, they still experience challenges in cognitive map formation and independent navigation. Three-dimensional (3D) tactile information is thus increasingly being considered to convey enriched spatial information, but it remains unclear if it can facilitate cognitive map formation compared to traditional two-dimensional (2D) tactile information. Consequently, the present study investigated the impact of the type of sensory input (tactile 2D vs. tactile 3D vs. a visual control condition) on cognitive map formation. To do so, early blind (EB, n = 13), late blind (LB, n = 12), and sighted control (SC, n = 14) participants were tasked to learn the layouts of mazes produced with different sensory information (tactile 2D vs. tactile 3D vs. visual control) and to infer routes from memory. Results show that EB manifested stronger cognitive map formation with 3D mazes, LB performed equally well with 2D and 3D tactile mazes, and SC manifested equivalent cognitive map formation with visual and 3D tactile mazes but were negatively impacted by 2D tactile mazes. 3D tactile maps therefore have the potential to improve spatial learning for EB and newly blind individuals through a reduction of cognitive overload. Installation of 3D tactile maps in public spaces should be considered to promote universal accessibility and reduce blind individuals' wayfinding deficits related to the inaccessibility of spatial information through non-visual means.

Different Types of Survey-Based Environmental Representations: Egocentric vs. Allocentric Cognitive Maps

The goal of the current study was to show the existence of distinct types of survey-based environmental representations, egocentric and allocentric, and provide experimental evidence that they are formed by different types of navigational strategies, path integration and map-based navigation, respectively. After traversing an unfamiliar route, participants were either disoriented and asked to point to non-visible landmarks encountered on the route (Experiment 1) or presented with a secondary spatial working memory task while determining the spatial locations of objects on the route (Experiment 2). The results demonstrate a double dissociation between the navigational strategies underlying the formation of allocentric and egocentric survey-based representation. Specifically, only the individuals who generated egocentric survey-based representations of the route were affected by disorientation, suggesting they relied primarily on a path integration strategy combined with landmark/scene processing at each route segment. In contrast, only allocentric-survey mappers were affected by the secondary spatial working memory task, suggesting their use of map-based navigation. This research is the first to show that path integration, in conjunction with egocentric landmark processing, is a distinct standalone navigational strategy underpinning the formation of a unique type of environmental representation-the egocentric survey-based representation.

Wayfinding and spatial perception among adolescents with mild intellectual disability

BACKGROUND

The study's aim was to examine whether spatial orientation can be improved in students with cognitive disabilities.

METHOD

Participants were 55 boys and girls with attention deficit and mild cognitive impairment from a special education school. The procedure included an intervention for two experimental groups that studied wayfinding and orientation in the environment: group #1 learned to use a map while navigating, and group #2 learned to use a Google navigation app with voice instructions. Two pre-post tests were applied: (1) Mental folding test for children (MFTC) and (2) field test with map.

RESULTS

Both groups improved their ability in navigation and wayfinding. No advantage for one learning method over the other was demonstrated, except for shortened navigation time in the group navigating with a map, and a slight though not significant tendency of improvement in the MFTC task in the group learning navigation using a voice app.

CONCLUSION

It is worth noting that the study did not examine the students' own preferences for the way of learning, which may have implications for the degree of possible improvement. Also, a longer period of the learning process might yield a clearer understanding concerning the differences between the two teaching methods that were examined.

Vision-Based Topological Mapping and Navigation With Self-Organizing Neural Networks

Spatial mapping and navigation are critical cognitive functions of autonomous agents, enabling one to learn an internal representation of an environment and move through space with real-time sensory inputs, such as visual observations. Existing models for vision-based mapping and navigation, however, suffer from memory requirements that increase linearly with exploration duration and indirect path following behaviors. This article presents e -TM, a self-organizing neural network-based framework for incremental topological mapping and navigation. e -TM models the exploration trajectories explicitly as episodic memory, wherein salient landmarks are sequentially extracted as "events" from streaming observations. A memory consolidation procedure then performs a playback mechanism and transfers the embedded knowledge of the environmental layout into spatial memory, encoding topological relations between landmarks. Fusion adaptive resonance theory (ART) networks, as the building block of the two memory modules, can generalize multiple input patterns into memory templates and, therefore, provide a compact spatial representation and support the discovery of novel shortcuts through inferences. For navigation, e -TM applies a transfer learning paradigm to integrate human demonstrations into a pretrained locomotion network for smoother movements. Experimental results based on VizDoom, a simulated 3-D environment, have shown that, compared to semiparametric topological memory (SPTM), a state-of-the-art model, e -TM reduces the time costs of navigation significantly while learning much sparser topological graphs.

Cognitive map formation supported by auditory, haptic, and multimodal information in persons with blindness

For efficient navigation, the brain needs to adequately represent the environment in a cognitive map. In this review, we sought to give an overview of literature about cognitive map formation based on non-visual modalities in persons with blindness (PWBs) and sighted persons. The review is focused on the auditory and haptic modalities, including research that combines multiple modalities and real-world navigation. Furthermore, we addressed implications of route and survey representations. Taking together, PWBs as well as sighted persons can build up cognitive maps based on non-visual modalities, although the accuracy sometime somewhat differs between PWBs and sighted persons. We provide some speculations on how to deploy information from different modalities to support cognitive map formation. Furthermore, PWBs and sighted persons seem to be able to construct route as well as survey representations. PWBs can experience difficulties building up a survey representation, but this is not always the case, and research suggests that they can acquire this ability with sufficient spatial information or training. We discuss possible explanations of these inconsistencies.

Predictive maps in rats and humans for spatial navigation

Much of our understanding of navigation comes from the study of individual species, often with specific tasks tailored to those species. Here, we provide a novel experimental and analytic framework integrating across humans, rats, and simulated reinforcement learning (RL) agents to interrogate the dynamics of behavior during spatial navigation. We developed a novel open-field navigation task ("Tartarus maze") requiring dynamic adaptation (shortcuts and detours) to frequently changing obstructions on the path to a hidden goal. Humans and rats were remarkably similar in their trajectories. Both species showed the greatest similarity to RL agents utilizing a "successor representation," which creates a predictive map. Humans also displayed trajectory features similar to model-based RL agents, which implemented an optimal tree-search planning procedure. Our results help refine models seeking to explain mammalian navigation in dynamic environments and highlight the utility of modeling the behavior of different species to uncover the shared mechanisms that support behavior.

Cognitive map formation through tactile map navigation in visually impaired and sighted persons

The human brain can form cognitive maps of a spatial environment, which can support wayfinding. In this study, we investigated cognitive map formation of an environment presented in the tactile modality, in visually impaired and sighted persons. In addition, we assessed the acquisition of route and survey knowledge. Ten persons with a visual impairment (PVIs) and ten sighted control participants learned a tactile map of a city-like environment. The map included five marked locations associated with different items. Participants subsequently estimated distances between item pairs, performed a direction pointing task, reproduced routes between items and recalled item locations. In addition, we conducted questionnaires to assess general navigational abilities and the use of route or survey strategies. Overall, participants in both groups performed well on the spatial tasks. Our results did not show differences in performance between PVIs and sighted persons, indicating that both groups formed an equally accurate cognitive map. Furthermore, we found that the groups generally used similar navigational strategies, which correlated with performance on some of the tasks, and acquired similar and accurate route and survey knowledge. We therefore suggest that PVIs are able to employ a route as well as survey strategy if they have the opportunity to access route-like as well as map-like information such as on a tactile map.

Chimpanzees (Pan troglodytes) navigate to find hidden fruit in a virtual environment

Almost all animals navigate their environment to find food, shelter, and mates. Spatial cognition of nonhuman primates in large-scale environments is notoriously difficult to study. Field research is ecologically valid, but controlling confounding variables can be difficult. Captive research enables experimental control, but space restrictions can limit generalizability. Virtual reality technology combines the best of both worlds by creating large-scale, controllable environments. We presented six chimpanzees with a seminaturalistic virtual environment, using a custom touch screen application. The chimpanzees exhibited signature behaviors reminiscent of real-life navigation: They learned to approach a landmark associated with the presence of fruit, improving efficiency over time; they located this landmark from novel starting locations and approached a different landmark when necessary. We conclude that virtual environments can allow for standardized testing with higher ecological validity than traditional tests in captivity and harbor great potential to contribute to longstanding questions in primate navigation, e.g., the use of landmarks, Euclidean maps, or spatial frames of reference.

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.

Voice Navigation Created by VIP Improves Spatial Performance in People with Impaired Vision

The difficulty associated with spatial navigation is one of the main obstacles to independent living for visually impaired people. With a lack of visual feedback, visually impaired people must identify information from the external environment through other sense organs. This study employed an observational survey to assess voice navigation version A, created by visually impaired people, and voice navigation version B, created by non-visually impaired people. Thirty-two simulated visually impaired people were assigned to conduct task assessments of voice navigation version A and version B. For mission 1, the mean completion rate is 0.988 ± 0.049 (version A); the mean error rate is 0.125 ± 0.182 (version A). For mission 2, the mean completion rate is 0.953 ± 0.148 (version A); the mean error rate is 0.094 ± 0.198 (version A). The assessment results concluded that version A has a higher completion rate (p = 0.001) and a lower error rate (p = 0.001). In the assessment of subjective satisfaction, all the indicators regarding the impression of navigation directives in version A were significantly superior to those indicators in version B. It appears that version A has a different logic of framing than version B. In future applications, a voice navigation version shall be built, according to the way visually impaired people think, because it will facilitate the direction guide when there is a lack of visual feedback.

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.

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.

Bayesian decision theory and navigation

Spatial navigation is a complex cognitive activity that depends on perception, action, memory, reasoning, and problem-solving. Effective navigation depends on the ability to combine information from multiple spatial cues to estimate one's position and the locations of goals. Spatial cues include landmarks, and other visible features of the environment, and body-based cues generated by self-motion (vestibular, proprioceptive, and efferent information). A number of projects have investigated the extent to which visual cues and body-based cues are combined optimally according to statistical principles. Possible limitations of these investigations are that they have not accounted for navigators' prior experiences with or assumptions about the task environment and have not tested complete decision models. We examine cue combination in spatial navigation from a Bayesian perspective and present the fundamental principles of Bayesian decision theory. We show that a complete Bayesian decision model with an explicit loss function can explain a discrepancy between optimal cue weights and empirical cues weights observed by (Chen et al. Cognitive Psychology, 95, 105-144, 2017) and that the use of informative priors to represent cue bias can explain the incongruity between heading variability and heading direction observed by (Zhao and Warren 2015b, Psychological Science, 26[6], 915-924). We also discuss (Petzschner and Glasauer's , Journal of Neuroscience, 31(47), 17220-17229, 2011) use of priors to explain biases in estimates of linear displacements during visual path integration. We conclude that Bayesian decision theory offers a productive theoretical framework for investigating human spatial navigation and believe that it will lead to a deeper understanding of navigational behaviors.

Spatial Navigation and Visuospatial Strategies in Typical and Atypical Aging

Age-related spatial navigation decline is more pronounced in patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD) dementia. We used a realistic-looking virtual navigation test suite to analyze different aspects of visuospatial processing in typical and atypical aging. A total of 219 older adults were recruited from the Czech Brain Aging Study cohort. Cognitively normal older adults (CN; n = 78), patients with amnestic MCI (n = 75), and those with mild AD dementia (n = 66) underwent three navigational tasks, cognitive assessment, and brain MRI. Route learning and wayfinding/perspective-taking tasks distinguished the groups as performance and learning declined and specific visuospatial strategies were less utilized with increasing cognitive impairment. Increased perspective shift and utilization of non-specific strategies were associated with worse task performance across the groups. Primacy and recency effects were observed across the groups in the route learning and the wayfinding/perspective-taking task, respectively. In addition, a primacy effect was present in the wayfinding/perspective-taking task in the CN older adults. More effective spatial navigation was associated with better memory and executive functions. The results demonstrate that a realistic and ecologically valid spatial navigation test suite can reveal different aspects of visuospatial processing in typical and atypical aging.

Vector-based pedestrian navigation in cities

How do pedestrians choose their paths within city street networks? Researchers have tried to shed light on this matter through strictly controlled experiments, but an ultimate answer based on real-world mobility data is still lacking. Here, we analyze salient features of human path planning through a statistical analysis of a massive dataset of GPS traces, which reveals that (1) people increasingly deviate from the shortest path when the distance between origin and destination increases and (2) chosen paths are statistically different when origin and destination are swapped. We posit that direction to goal is a main driver of path planning and develop a vector-based navigation model; the resulting trajectories, which we have termed pointiest paths, are a statistically better predictor of human paths than a model based on minimizing distance with stochastic effects. Our findings generalize across two major US cities with different street networks, hinting to the fact that vector-based navigation might be a universal property of human path planning.

Cognitive maps in the wild: revealing the use of metric information in black howler monkey route navigation

When navigating, wild animals rely on internal representations of the external world – called ‘cognitive maps’ – to take movement decisions. Generally, flexible navigation is hypothesized to be supported by sophisticated spatial skills (i.e. Euclidean cognitive maps); however, constrained movements along habitual routes are the most commonly reported navigation strategy. Even though incorporating metric information (i.e. distances and angles between locations) in route-based cognitive maps would likely enhance an animal's navigation efficiency, there has been no evidence of this strategy reported for non-human animals to date. Here, we examined the properties of the cognitive map used by a wild population of primates by testing a series of cognitive hypotheses against spatially explicit movement simulations. We collected 3104 h of ranging and behavioural data on five groups of black howler monkeys (Alouatta pigra) at Palenque National Park, Mexico, from September 2016 through August 2017. We simulated correlated random walks mimicking the ranging behaviour of the study subjects and tested for differences between observed and simulated movement patterns. Our results indicated that black howler monkeys engaged in constrained movement patterns characterized by a high path recursion tendency, which limited their capacity to travel in straight lines and approach feeding trees from multiple directions. In addition, we found that the structure of observed route networks was more complex and efficient than simulated route networks, suggesting that black howler monkeys incorporate metric information into their cognitive map. Our findings not only expand the use of metric information during route navigation to non-human animals, but also highlight the importance of considering efficient route-based navigation as a cognitively demanding mechanism.

Highlighted Article: Black howler monkeys rely on route-based cognitive maps, which constrain their movement decisions, but likely incorporate metric information to navigate more efficiently along frequently used routes.

Cognitive map formation through haptic and visual exploration of tactile city-like maps

In this study, we compared cognitive map formation of small-scale models of city-like environments presented in visual or tactile/haptic modalities. Previous research often addresses only a limited amount of cognitive map aspects. We wanted to combine several of these aspects to elucidate a more complete view. Therefore, we assessed different types of spatial information, and consider egocentric as well as allocentric perspectives. Furthermore, we compared haptic map learning with visual map learning. In total 18 sighted participants (9 in a haptic condition, 9 visuo-haptic) learned three tactile maps of city-like environments. The maps differed in complexity, and had five marked locations associated with unique items. Participants estimated distances between item pairs, rebuilt the map, recalled locations, and navigated two routes, after learning each map. All participants overall performed well on the spatial tasks. Interestingly, only on the complex maps, participants performed worse in the haptic condition than the visuo-haptic, suggesting no distinct advantage of vision on the simple map. These results support ideas of modality-independent representations of space. Although it is less clear on the more complex maps, our findings indicate that participants using only haptic or a combination of haptic and visual information both form a quite accurate cognitive map of a simple tactile city-like map.

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.

Serial memory for landmarks encountered during route navigation

The present study demonstrates similarities between route learning and classical tests of serial order memory. Here, we investigated serial memory for landmarks in a route learning task, in younger and older adults. We analysed data from a route learning task with 12 landmarks. Participants (88 younger and 77 older) learned a route using either a Fixed Learning (3 exposures to the route) or Flexible Learning (repeated exposures until successful navigation was achieved) procedure. Following route learning, participants completed Immediate Free Recall (IFR) and Free Reconstruction of Order (Free RoO) of the landmarks. We show clear acquisition of sequence memory for landmarks for both age groups, with Free RoO producing a bowed serial position curve. IFR produced recency effects but no primacy effects in fixed learning, with recency reduced following flexible learning for both age groups. Younger adults displayed a primacy bias for the first item recalled in both learning conditions, as did the older adults in the flexible learning condition. In contrast, older adults displayed a recency bias in the fixed learning condition. Evidence of contiguity in IFR was present only for younger adults in the flexible learning condition. Findings are broadly consistent with results from typical short-term list learning procedures and support the universality of sequence learning effects, which we demonstrate are generalisable to a navigation context.

Route selection in non-Euclidean virtual environments

The way people choose routes through unfamiliar environments provides clues about the underlying representation they use. One way to test the nature of observers' representation is to manipulate the structure of the scene as they move through it and measure which aspects of performance are significantly affected and which are not. We recorded the routes that participants took in virtual mazes to reach previously-viewed targets. The mazes were either physically realizable or impossible (the latter contained 'wormholes' that altered the layout of the scene without any visible change at that moment). We found that participants could usually find the shortest route between remembered objects even in physically impossible environments, despite the gross failures in pointing that an earlier study showed are evident in the physically impossible environment. In the physically impossible conditions, the choice made at a junction was influenced to a greater extent by whether that choice had, in the past, led to the discovery of a target (compared to a shortest-distance prediction). In the physically realizable mazes, on the other hand, junction choices were determined more by the shortest distance to the target. This pattern of results is compatible with the idea of a graph-like representation of space that can include information about previous success or failure for traversing each edge and also information about the distance between nodes. Our results suggest that complexity of the maze may dictate which of these is more important in influencing navigational choices.

Combining cues to judge distance and direction in an immersive virtual reality environment

When we move, the visual direction of objects in the environment can change substantially. Compared with our understanding of depth perception, the problem the visual system faces in computing this change is relatively poorly understood. Here, we tested the extent to which participants' judgments of visual direction could be predicted by standard cue combination rules. Participants were tested in virtual reality using a head-mounted display. In a simulated room, they judged the position of an object at one location, before walking to another location in the room and judging, in a second interval, whether an object was at the expected visual direction of the first. By manipulating the scale of the room across intervals, which was subjectively invisible to observers, we put two classes of cue into conflict, one that depends only on visual information and one that uses proprioceptive information to scale any reconstruction of the scene. We find that the sensitivity to changes in one class of cue while keeping the other constant provides a good prediction of performance when both cues vary, consistent with the standard cue combination framework. Nevertheless, by comparing judgments of visual direction with those of distance, we show that judgments of visual direction and distance are mutually inconsistent. We discuss why there is no need for any contradiction between these two conclusions.

Travel planning in men and women. Who is better?

Gender differences are often reported in spatial abilities, most of the times favouring men. Even during wayfinding, which requires planning and decision-making, such as choosing roads to take or shortcuts, men are in general better and faster than women. Although different interpretations have been proposed to explain men’s advantage in navigation, no study has explored the possibility that it could be due to men’s better travel planning ability. This latter has been recently identified as a distinct kind of planning that allows implementing an efficient navigational strategy in accordance with the environmental features. Therefore, the present study was aimed at investigating gender differences in travel planning ability. We compared men and women in performing the Key Search Task that requires to implement a strategy to search for a lost object in a wide imagined space. Results showed that men outperform women in both the overall performance and in some specific indexes of the total score. Men had a better travel planning ability with respect to women, outperforming women in configuring the planned strategy and choosing the best point to enter the imagined field. Therefore, men seem to plan the best navigational strategy and appear more cognitively flexible than women in adapting the strategy at the environmental features. The two genders did not differ in the time spent to solve the task. This finding suggests that differences in travel planning skills can contribute in explaining gender differences in wayfinding and spatial orientation.

Navigating in a challenging semiarid environment: the use of a route-based mental map by a small-bodied neotropical primate

To increase efficiency in the search for resources, many animals rely on their spatial abilities. Specifically, primates have been reported to use mostly topological and rarely Euclidean maps when navigating in large-scale space. Here, we aimed to investigate if the navigation of wild common marmosets inhabiting a semiarid environment is consistent with a topological representation and how environmental factors affect navigation. We collected 497 h of direct behavioral and GPS information on a group of marmosets using a 2-min instantaneous focal animal sampling technique. We found that our study group reused not only long-route segments (mean of 1007 m) but entire daily routes, a pattern that is not commonly seen in primates. The most frequently reused route segments were the ones closer to feeding sites, distant to resting sites, and in areas sparse in tree vegetation. We also identified a total of 56 clustered direction change points indicating that the group modified their direction of travel. These changes in direction were influenced by their close proximity to resting and feeding sites. Despite our small sample size, the obtained results are important and consistent with the contention that common marmosets navigate using a topological map that seems to benefit these animals in response to the exploitation of clustered exudate trees. Based on our findings, we hypothesize that the Caatinga landscape imposes physical restrictions in our group's navigation such as gaps in vegetation, small trees and xerophytic plants. This study, based on preliminary evidence, raises the question of whether navigation patterns are an intrinsic characteristic of a species or are ecologically dependent and change according to the environment.

The relationship between mental and physical space and its impact on topographical disorientation

We generate mental representations of space to facilitate our ability to remember things and navigate our environment. Many studies implicitly assume that these representations simply reflect the environments that they represent without considering other factors that influence the extent to which this is the case. Here, we bring together findings from cognitive psychology, environmental psychology, geography, urban planning, and neuroscience to discuss how internalizing the environment involves a complex interplay between bottom-up and top-down mental processes and depends on key characteristics of the physical environment itself. We describe how mental space is structured, the ways in which mental and physical space converge and diverge, and the disparate but complementary techniques used to assess these relationships. Finally, we contextualize this knowledge in the clinical populations affected by acquired and developmental topographical disorientation, exploring mechanisms that cause these patients to get lost in familiar surroundings.

The impact of cognitive aging on route learning rate and the acquisition of landmark knowledge

Aging is accompanied by changes in general cognitive functioning which may impact the learning rate of older adults; however, this is often not controlled for in cognitive aging studies. We investigated the contribution of differences in learning rates to age-related differences in landmark knowledge acquired from route learning. In Experiment 1 we used a standard learning procedure in which participants received a fixed amount of exposure to a route. Consistent with previous research, we found age-related deficits in associative cue and landmark sequence knowledge. Experiment 2 controlled for differences in learning rates by using a flexible exposure learning procedure. Specifically, participants were trained to a performance criterion during route learning before being tested on the content of their route knowledge. While older adults took longer to learn the route than younger adults, the age-related differences in associative cue knowledge were abolished. The deficit in landmark sequence knowledge, however, remained. Experiment 3 replicated these results and introduced a test situation in which a deficit in landmark sequence knowledge yielded an increased likelihood of disorientation in older adults. The findings of this study suggest that age-related deficits in landmark associative cue knowledge are attenuated by controlling for learning rates. In contrast, landmark sequence knowledge deficits persist and are best explained by changes in the learning strategy of older adults to acquire task essential associative cue knowledge at the expense of supplementary sequence knowledge.

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.

Reframing spatial frames of reference: What can aging tell us about egocentric and allocentric navigation?

Representations of space in mind are crucial for navigation, facilitating processes such as remembering landmark locations, understanding spatial relationships between objects, and integrating routes. A significant problem, however, is the lack of consensus on how these representations are encoded and stored in memory. Specifically, the nature of egocentric and allocentric frames of reference in human memory is widely debated. Yet, in recent investigations of the spatial domain across the lifespan, these distinctions in mnemonic spatial frames of reference have identified age-related impairments. In this review, we survey the ways in which different terms related to spatial representations in memory have been operationalized in past aging research and suggest a taxonomy to provide a common language for future investigations and theoretical discussion. This article is categorized under: Psychology > Memory Neuroscience > Cognition Psychology > Development and Aging.

Differential Brain Activity in Regions Linked to Visuospatial Processing During Landmark-Based Navigation in Young and Healthy Older Adults

Older adults have difficulties in navigating unfamiliar environments and updating their wayfinding behavior when faced with blocked routes. This decline in navigational capabilities has traditionally been ascribed to memory impairments and dysexecutive function, whereas the impact of visual aging has often been overlooked. The ability to perceive visuospatial information such as salient landmarks is essential to navigating efficiently. To date, the functional and neurobiological factors underpinning landmark processing in aging remain insufficiently characterized. To address this issue, functional magnetic resonance imaging (fMRI) was used to investigate the brain activity associated with landmark-based navigation in young and healthy older participants. The performances of 25 young adults (μ = 25.4 years, σ = 2.7; seven females) and 17 older adults (μ = 73.0 years, σ = 3.9; 10 females) were assessed in a virtual-navigation task in which they had to orient using salient landmarks. The underlying whole-brain patterns of activity as well as the functional roles of specific cerebral regions involved in landmark processing, namely the parahippocampal place area (PPA), the occipital place area (OPA), and the retrosplenial cortex (RSC), were analyzed. Older adults' navigational abilities were overall diminished compared to young adults. Also, the two age groups relied on distinct navigational strategies to solve the task. Better performances during landmark-based navigation were associated with increased neural activity in an extended neural network comprising several cortical and cerebellar regions. Direct comparisons between age groups revealed that young participants had greater anterior temporal activity. Also, only young adults showed significant activity in occipital areas corresponding to the cortical projection of the central visual field during landmark-based navigation. The region-of-interest analysis revealed an increased OPA activation in older adult participants during the landmark condition. There were no significant between-group differences in PPA and RSC activations. These preliminary results hint at the possibility that aging diminishes fine-grained information processing in occipital and temporal regions, thus hindering the capacity to use landmarks adequately for navigation. Keeping sight of its exploratory nature, this work helps towards a better comprehension of the neural dynamics subtending landmark-based navigation and it provides new insights on the impact of age-related visuospatial processing differences on navigation capabilities.

Construction of Cognitive Maps to Improve Reading Performance by Text Signaling: Reading Text on Paper Compared to on Screen

Reading text from a screen has been shown to be less effective compared with reading text from paper. Various signals may provide both background information and navigational cues, and may promote the construction of cognitive maps during on-screen reading, thus improving reading performance. This study randomly divided 75 college students into a paper reading group and an on-screen reading group. Both groups were tested for navigation and reading comprehension in response to three different forms of signaling (plain text, physical signaling, and verbal signaling). The results showed that when plain text was presented, the navigation and comprehension scores of the paper reading group were significantly higher than those of the on-screen reading group. However, no significant difference was found between both groups under signaling conditions. The navigation and comprehension scores of both groups were significantly higher under signaling conditions than under plain text. Moreover, the comprehension score of the on-screen reading group under physical signaling was significantly higher than that under verbal signaling. This research suggested that signals help to construct cognitive maps and effectively improve reading performance. Besides, physical signaling, such as underlining and bold formatting, is more effective for on-screen reading. The present study provides a practical and effective approach for improving on-screen reading based on cognitive map theory.

Lessons from reinforcement learning for biological representations of space

Neuroscientists postulate 3D representations in the brain in a variety of different coordinate frames (e.g. 'head-centred', 'hand-centred' and 'world-based'). Recent advances in reinforcement learning demonstrate a quite different approach that may provide a more promising model for biological representations underlying spatial perception and navigation. In this paper, we focus on reinforcement learning methods that reward an agent for arriving at a target image without any attempt to build up a 3D 'map'. We test the ability of this type of representation to support geometrically consistent spatial tasks such as interpolating between learned locations using decoding of feature vectors. We introduce a hand-crafted representation that has, by design, a high degree of geometric consistency and demonstrate that, in this case, information about the persistence of features as the camera translates (e.g. distant features persist) can improve performance on the geometric tasks. These examples avoid Cartesian (in this case, 2D) representations of space. Non-Cartesian, learned representations provide an important stimulus in neuroscience to the search for alternatives to a 'cognitive map'.

Effects of visual map complexity on the attentional processing of landmarks

In the era of smartphones, route-planning and navigation is supported by freely and globally available web mapping services, such as OpenStreetMap or Google Maps. These services provide digital maps, as well as route planning functions that visually highlight the suggested route in the map. Additionally, such digital maps contain landmark pictograms, i.e. representations of salient objects in the environment. These landmark representations are, amongst other reference points, relevant for orientation, route memory, and the formation of a cognitive map of the environment. The amount of visible landmarks in maps used for navigation and route planning depends on the width of the displayed margin areas around the route. The amount of further reference points is based on the visual complexity of the map. This raises the question how factors like the distance of landmark representations to the route and visual map complexity determine the relevance of specific landmarks for memorizing a route. In order to answer this question, two experiments that investigated the relation between eye fixation patterns on landmark representations, landmark positions, route memory and visual map complexity were carried out. The results indicate that the attentional processing of landmark representations gradually decreases with an increasing distance to the route, decision points and potential decision points. Furthermore, this relation was found to be affected by the visual complexity of the map. In maps with low visual complexity, landmark representations further away from the route are fixated. However, route memory was not found to be affected by visual complexity of the map. We argue that map users might require a certain amount of reference points to form spatial relations as a foundation for a mental representation of space. As maps with low visual complexity offer less reference points, people need to scan a wider area. Therefore, visual complexity of the area displayed in a map should be considered in navigation-oriented map design by increasing displayed margins around the route in maps with a low visual complexity. In order to verify our assumption that the amount of reference points not only affects visual attention processes, but also the formation of a mental representation of space, additional research is required.

Cognitive focus affects spatial decisions under conditions of uncertainty

Finding one’s way to a destination is a common, everyday task that often relies on spatial information provided by humans and/or automatic devices. However, the information can be inaccurate. How we decide which route to take will depend on our thoughts about the available route information, including who or what provided it, and how these sources may be associated with differential accuracy and fallibility. In three experiments (previously reported in Brunyé et al. (Q J Exper Psychol 68(3):585–607, 2015)), we found that when route directions conflicted with the perceived environment, people trusted the landmark information other humans provided, but relied on the turn direction information from an automatic device. But what guides these behavioral results? Here we present a systematic linguistic analysis of retrospective reports that sheds some light on how information about the direction source affects cognitive focus. A focus on direction sources in the instruction triggered a cognitive focus on the direction source throughout. Participants who systematically switched strategies focused more on features of the scenario than those who did not. Non-switching strategies were associated with a higher focus on the participants’ own reasoning processes, in particular when relying on turn information. These results highlight how cognitive focus is guided by scenario factors and individual preferences, triggering inferences that influence decisions.

Saccular function is associated with both angular and distance errors on the triangle completion test

OBJECTIVE

The present study was designed to determine whether healthy older adults with age-related vestibular loss have deficits in spatial navigation.

METHODS

154 adults participating in the Baltimore Longitudinal Study of Aging were tested for semicircular canal, saccular, and utricular function and spatial navigation ability using the blindfolded Triangle Completion Test (TCT). Multiple linear regression was used to investigate the relationships between each measure of vestibular function and performance on the TCT (angular error, end point error, and distance walked) while controlling for age and sex.

RESULTS

Individuals with abnormal saccular function made larger angular errors (β = 4.2°, p < 0.05) and larger end point errors (β = 13.6 cm, p < 0.05). Independent of vestibular function, older age was associated with larger angular (β's = 2.2-2.8°, p's < 0.005) and end point errors (β's = 7.5-9.0 cm, p's < 0.005) for each decade increment in age.

CONCLUSIONS

Saccular function appears to play a prominent role in accurate spatial navigation during a blindfolded navigation task.

SIGNIFICANCE

We hypothesize that gravitational cues detected by the saccule may be integrated into estimation of place as well as heading direction.

Age-related preference for geometric spatial cues during real-world navigation

Ageing effects on spatial navigation are characterized mainly in terms of impaired allocentric strategies. However, an alternative hypothesis is that navigation difficulties in aged people are associated with deficits in processing and encoding spatial cues. We tested this hypothesis by studying how geometry and landmark cues control navigation in young and older adults in a real, ecological environment. Recordings of body and gaze dynamics revealed a preference for geometry-based navigation in older adults, and for landmark-based navigation in younger ones. While cue processing was associated with specific fixation patterns, advanced age manifested itself in a longer reorientation time, reflecting an unbalanced exploration-exploitation trade-off in scanning policies. Moreover, a battery of tests revealed a specific cognitive deficit in older adults with geometric preference. These results suggest that allocentric strategy deficits in ageing can result from difficulties related to landmark coding, and predict recovery of allocentric strategies in geometrically polarized environments.

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.

No single, stable 3D representation can explain pointing biases in a spatial updating task

People are able to keep track of objects as they navigate through space, even when objects are out of sight. This requires some kind of representation of the scene and of the observer’s location but the form this might take is debated. We tested the accuracy and reliability of observers’ estimates of the visual direction of previously-viewed targets. Participants viewed four objects from one location, with binocular vision and small head movements then, without any further sight of the targets, they walked to another location and pointed towards them. All conditions were tested in an immersive virtual environment and some were also carried out in a real scene. Participants made large, consistent pointing errors that are poorly explained by any stable 3D representation. Any explanation based on a 3D representation would have to posit a different layout of the remembered scene depending on the orientation of the obscuring wall at the moment the participant points. Our data show that the mechanisms for updating visual direction of unseen targets are not based on a stable 3D model of the scene, even a distorted one.

Alternative spin on phylogenetically inherited spatial reference frames

People make use of different frames of reference (north-south; left-right) to talk about space. To explore the cognitive capacity that children bring to learning spatial language, Haun, Rapold, Call, Janzen, and Levinson (2006) examined children's ability to notice and abstract invariant frames of references across instances. They found that 4-year-olds and non-human great apes often noticed environment-defined allocentric relations and not body-defined egocentric ones, leading them to conclude that preschoolers are ready to learn environment-defined terms (e.g. "uphill"), but not body-defined ones (e.g., "left"). However, such a conclusion may be premature. In four new experiments we demonstrate that the previous findings could be an artifact of specific task constraints. With minor experiment modifications, similar-aged children readily noticed egocentric relations. Reviewing additional research, we provide an account of what makes acquiring frames of reference easy or difficult, and why full mastery of terms like "left" and "right" may take many years under normal circumstances.

A cognitive map in a poison frog

A fundamental question in cognitive science is whether an animal can use a cognitive map. A cognitive map is a mental representation of the external world, and knowledge of one's place in this world, that can be used to determine efficient routes to any destination. Many birds and mammals are known to employ a cognitive map, but whether other vertebrates can create a cognitive map is less clear. Amphibians are capable of using beacons, gradients and landmarks when navigating, and many are proficient at homing. Yet only one prior study directly tested for a cognitive map in amphibians, with negative results. Poison frogs exhibit unusually complex social and spatial behaviors and are capable of long-distance homing after displacement, suggesting that they may be using complex spatial navigation strategies in nature. Here, we trained the poison frog Dendrobates auratus in a modified Morris water maze that was designed to suppress thigmotaxis to the maze wall, promoting exploration of the arena. In our moat maze, the poison frogs were able to use a configuration of visual cues to find the hidden platform. Moreover, we demonstrate that they chose direct paths to the goal from multiple random initial positions, a hallmark of a cognitive map. The performance of the frogs in the maze was qualitatively similar to that of rodents, suggesting that the potential to evolve a cognitive map is an evolutionarily conserved trait of vertebrates.

Sex differences in navigation strategy and efficiency

Research on human navigation has indicated that males and females differ in self-reported navigation strategy as well as objective measures of navigation efficiency. In two experiments, we investigated sex differences in navigation strategy and efficiency using an objective measure of strategy, the dual-solution paradigm (DSP; Marchette, Bakker, & Shelton, 2011). Although navigation by shortcuts and learned routes were the primary strategies used in both experiments, as in previous research on the DSP, individuals also utilized route reversals and sometimes found the goal location as a result of wandering. Importantly, sex differences were found in measures of both route selection and navigation efficiency. In particular, males were more likely to take shortcuts and reached their goal location faster than females, while females were more likely to follow learned routes and wander. Self-report measures of strategy were only weakly correlated with objective measures of strategy, casting doubt on their usefulness. This research indicates that the sex difference in navigation efficiency is large, and only partially related to an individual's navigation strategy as measured by the dual-solution paradigm.

Non-Euclidean navigation

A basic set of navigation strategies supports navigational tasks ranging from homing to novel detours and shortcuts. To perform these last two tasks, it is generally thought that humans, mammals and perhaps some insects possess Euclidean cognitive maps, constructed on the basis of input from the path integration system. In this article, I review the rationale and behavioral evidence for this metric cognitive map hypothesis, and find it unpersuasive: in practice, there is little evidence for truly novel shortcuts in animals, and human performance is highly unreliable and biased by environmental features. I develop the alternative hypothesis that spatial knowledge is better characterized as a labeled graph: a network of paths between places augmented with local metric information. What distinguishes such a cognitive graph from a metric cognitive map is that this local information is not embedded in a global coordinate system, so spatial knowledge is often geometrically inconsistent. Human path integration appears to be better suited to piecewise measurements of path lengths and turn angles than to building a consistent map. In a series of experiments in immersive virtual reality, we tested human navigation in non-Euclidean environments and found that shortcuts manifest large violations of the metric postulates. The results are contrary to the Euclidean map hypothesis and support the cognitive graph hypothesis. Apparently Euclidean behavior, such as taking novel detours and approximate shortcuts, can be explained by the adaptive use of non-Euclidean strategies.