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Using an appropriate spatial frame of reference (FoR) is crucial for solving spatial and communication problems. This study investigated the development of FoR preferences and the effects of landmark availability on these preferences. The participants were Japanese‐speaking children (aged 4–6 years) and adults, who were instructed to remember a row of three animals presented on a table, move to another table behind them, and reconstruct the array. Landmark availability was manipulated by varying the distance between the two tables. The results revealed that both children and adults tended to use an egocentric FoR, which increased with age. The frequency of an allocentric FoR was greater in the short‐distance condition, which had more available landmarks, than in the long‐distance condition. Regarding children's FoR, the availability of landmarks should be considered, rather than adopting the stereotypical view that children prefer an FoR that corresponds to their language. [ABSTRACT FROM AUTHOR]

The anterior and lateral thalamus (ALT) contains head direction cells that signal the directional orientation of an individual within the environment. ALT has direct and indirect connections with the parietal cortex (PC), an area hypothesized to play a role in coordinating viewer‐dependent and viewer‐independent spatial reference frames. This coordination between reference frames would allow an individual to translate movements toward a desired location from memory. Thus, ALT‐PC functional connectivity would be critical for moving toward remembered allocentric locations. This hypothesis was tested in rats with a place‐action task that requires associating an appropriate action (left or right turn) with a spatial location. There are four arms, each offset by 90°, positioned around a central starting point. A trial begins in the central starting point. After exiting a pseudorandomly selected arm, the rat had to displace the correct object covering one of two (left versus right) feeding stations to receive a reward. For a pair of arms facing opposite directions, the reward was located on the left, and for the other pair, the reward was located on the right. Thus, each reward location had a different combination of allocentric location and egocentric action. Removal of an object was scored as correct or incorrect. Trials in which the rat did not displace any objects were scored as "no selection" trials. After an object was removed, the rat returned to the center starting position and the maze was reset for the next trial. To investigate the role of the ALT‐PC network, muscimol inactivation infusions targeted bilateral PC, bilateral ALT, or the ALT‐PC network. Muscimol sessions were counterbalanced and compared to saline sessions within the same animal. All inactivations resulted in decreased accuracy, but only bilateral PC inactivations resulted in increased non selecting, increased errors, and longer latency responses on the remaining trials. Thus, the ALT‐PC circuit is critical for linking an action with a spatial location for successful navigation. [ABSTRACT FROM AUTHOR]

Neurons in the rat postrhinal cortex (POR) respond to the egocentric (observer‐centered) bearing and distance of the boundaries, or geometric center, of an enclosed space. Understanding of the precise geometric and sensory properties of the environment that generate these signals is limited. Here we model how this signal may relate to visual perception of motion parallax along environmental boundaries. A behavioral extension of this tuning is the known 'centering response', in which animals follow a spatial gradient function based on boundary parallax to guide behavior toward the center of a corridor or enclosure. Adding an allocentric head direction signal to this representation can translate the gradient across two‐dimensional space and provide a new gradient for directing behavior to any location. We propose a model for how this signal may support goal‐directed navigation via projections to the dorsomedial striatum. The result is a straightforward code for navigational variables derived from visual geometric properties of the surrounding environment, which may be used to map space and transform incoming sensory information into an appropriate motor output. [ABSTRACT FROM AUTHOR]

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 > MemoryNeuroscience > CognitionPsychology > Development and Aging [ABSTRACT FROM AUTHOR]

Cognitive biases for encoding spatial information (orientation strategies) in relation to self (egocentric) or landmarks (allocentric) differ between species or populations according to the habitats they occupy. Whether biases in orientation strategy determine early habitat selection or if individuals adapt their biases following experience is unknown. We determined orientation strategies of pheasants, Phasianus colchicus, using a dual‐strategy maze with an allocentric probe trial, before releasing them (n = 20) into a novel landscape, where we monitored their movement and habitat selection. In general, pheasants selected for woodland over non‐woodland habitat, but allocentric‐biased individuals exhibited weaker avoidance of non‐woodland habitat, where we expected allocentric navigation to be more effective. Sex did not influence selection but was associated with speed and directional persistence in non‐woodland habitat. Our results suggest that an individual's habitat selection is associated with inherent cognitive bias in early life, but it is not yet clear what advantages this may offer. [ABSTRACT FROM AUTHOR]

The most used frames of reference in spatial memory, which allows us to move through the environment, are the egocentric, related to one's own perspective, and the allocentric, based on environmental cues. Although many tasks have been proposed, those that evaluate the two frames of reference separately and compare adults and children are scarce. Our aim was to assess egocentric and allocentric spatial orientation in young children and young adults, comparing between ages, frames of reference and gender. The Egocentric and Allocentric Spatial Memory tests were used. Adults performed better than children on both tasks. Children performed equally in both frames of reference, but adults were more efficient on the allocentric test. Gender did not seem relevant in the performance of either group. Overall, egocentric and allocentric spatial memory are not fully developed at the age of 7 and children do not master any strategy above the other. Highlights: Do school‐aged children reach adults performance in egocentric and allocentric spatial memory?Two experimental tasks, Egocentric and Allocentric Spatial Memory tests, were used for assessment. Significant differences were found between children from 5‐to‐7 years and adults.Egocentric and allocentric frameworks are not fully developed at 7 years. Children may not rely on one specific framework for their orientation. [ABSTRACT FROM AUTHOR]

Introduction: Spatial orientation relies mainly on two frameworks. The egocentric depends on our own position and point of view. The allocentric relies on remembering, recalling, and recognizing environmental stimuli called landmarks. The aim of this study was to analyze the egocentric and allocentric spatial memory performance in children of different ages using two experimental memory card‐placing tasks. We also aimed to examine relationships between spatial memory and other cognitive, physiological, and behavioral factors that, potentially, could be associated with spatial memory performance. Those were other visuospatial functions, the regular behavior of the child, cortisol levels, and daily life spatial memory. Methods: We assessed 62 children (5, 6, and 7 years) using card‐placing tasks. We used RIST for IQ evaluation and subtest from NEPSY‐II for visuospatial ability assessment. Collection of saliva sample was carried out for cortisol analysis. Parents completed BASC questionnaire for behavioral evaluation and ECM‐Q questionnaire for daily life spatial memory evaluation. Results: Our results showed that older children performed better on mental rotation. Directionality, map interpretation, and daily memory were directly associated with both egocentric and allocentric orientation. Egocentric performance was positively related to leadership abilities but negatively to depression and atypicality, while allocentric performance was directly associated with adaptive behavior but inversely with hyperactivity. Finally, cortisol values were positively associated with allocentric performance. Conclusions: Our study shows the development of different spatial abilities between 5 and 7 years, as well as the relationship between orientation performance, visuospatial skills, behavior, and cortisol. [ABSTRACT FROM AUTHOR]

In addition to its role in visuospatial navigation and the generation of spatial representations, in recent years, the hippocampus has been proposed to support perceptual processes. This is especially the case where high‐resolution details, in the form of fine‐grained relationships between features such as angles between components of a visual scene, are involved. An unresolved question is how, in the visual domain, perspective‐changes are differentiated from allocentric changes to these perceived feature relationships, both of which may be argued to involve the hippocampus. We conducted functional magnetic resonance imaging of the brain response (corroborated through separate event‐related potential source‐localization) in a passive visuospatial oddball‐paradigm to examine to what extent the hippocampus and other brain regions process changes in perspective, or configuration of abstract, three‐dimensional structures. We observed activation of the left superior parietal cortex during perspective shifts, and right anterior hippocampus in configuration‐changes. Strikingly, we also found the cerebellum to differentiate between the two, in a way that appeared tightly coupled to hippocampal processing. These results point toward a relationship between the cerebellum and the hippocampus that occurs during perception of changes in visuospatial information that has previously only been reported with regard to visuospatial navigation. [ABSTRACT FROM AUTHOR]

Aim: This study examined the contribution of the social network to one's sense of belonging to the community (SCB) in two different long‐term care settings: Continuing care retirement communities (CCRCs) and adult day care centers (ADCCs). Methods: Overall, 245 respondents participated in both waves of the study that were spaced about 1 year apart. Results: Results show that constraint in the social network (e.g., being socially invested in a single group of interconnected ties) is particularly detrimental for CCRC residents, but not for ADCC participants. Betweenness, defined as the number of shortest paths that pass through the focal person, was not significantly related to SCB. In addition, the size of the egocentric network, obtained through a name generator of a list of all potentially meaningful individuals identified by respondents, was directly correlated with SCB at follow‐up. Conclusions: The findings are discussed in light of differences between the two long‐term care settings and the different social network indicators examined in this study. [ABSTRACT FROM AUTHOR]

Introduction: Spatial navigation deficits are observed in Alzheimer's disease cross‐sectionally, but prediction of longitudinal clinical decline has been less examined. Methods: Cognitive mapping (CM) was assessed in 95 participants and route learning (RL) was assessed in 65 participants at baseline. Clinical progression over an average of 4 to 5 years was assessed using the clinical dementia rating (CDR) scale. Relative predictive ability was compared to episodic memory, hippocampus, and cerebrospinal fluid biomarkers (phosphorylated tau/amyloid β 42 (ptau181/Aβ42) ratio). Results: CM and RL were predictors of clinical progression (P's < 0.032). All measures, except RL‐Learning remained predictors with episodic memory in models (P's < 0.048). Only RL‐Retrieval remained a predictor when ptau181/Aβ42 was included (P < 0.001). CM interacted with hippocampus and ptau181/Aβ42 in prediction (P's < 0.013). CM, RL, and episodic memory evidenced strong diagnostic accuracy (area under the curve (AUC) = 0.894, 0.794, and 0.735, respectively); CM tended to perform better than episodic memory (P = 0.056). Discussion: Baseline spatial navigation performance may be appropriate for assessing risk of clinical progression. [ABSTRACT FROM AUTHOR]

Episodic memory is defined as the ability to recall events in a spatiotemporal context. Formation of such memories is critically dependent on the hippocampal formation and its inputs from the entorhinal cortex. To be able to support the formation of episodic memories, entorhinal cortex and hippocampal formation should contain a neuronal code that follows several requirements. First, the code should include information about position of the agent ("where"), sequence of events ("when"), and the content of the experience itself ("what"). Second, the code should arise instantly thereby being able to support memory formation of one‐shot experiences. For successful encoding and to avoid interference between memories during recall, variations in location, time, or in content of experience should result in unique ensemble activity. Finally, the code should capture several different resolutions of experience so that the necessary details relevant for future memory‐based predictions will be stored. We review how neuronal codes in entorhinal cortex and hippocampus follow these requirements and argue that during formation of episodic memories entorhinal cortex provides hippocampus with instant information about ongoing experience. Such information originates from (a) spatially modulated neurons in medial entorhinal cortex, including grid cells, which provide a stable and universal positional metric of the environment; (b) a continuously varying signal in lateral entorhinal cortex providing a code for the temporal progression of events; and (c) entorhinal neurons coding the content of experiences exemplified by object‐coding and odor‐selective neurons. During formation of episodic memories, information from these systems are thought to be encoded as unique sequential ensemble activity in hippocampus, thereby encoding associations between the content of an event and its spatial and temporal contexts. Upon exposure to parts of the encoded stimuli, activity in these ensembles can be reinstated, leading to reactivation of the encoded activity pattern and memory recollection. [ABSTRACT FROM AUTHOR]

Evidence that the hippocampus is critical for spatial memory in nonnavigational tests is mixed. A recent study reported that temporary hippocampal inactivation impaired spatial memory in the nonnavigational Hamilton Search Task in monkeys. However, several studies have documented no impairment on other nonnavigational spatial memory tests following permanent hippocampal lesions. It was hypothesized that transient, but not permanent, hippocampal disruption produces deficits because monkeys undergoing transient inactivation continue to try to use a hippocampal‐dependent strategy, whereas monkeys with permanent lesions use a nonhippocampal‐dependent strategy. We evaluated this hypothesis by testing five rhesus monkeys with hippocampal lesions and five controls on a computerized analogue of the Hamilton Search Task. On each trial, monkeys saw an array of squares on a touchscreen, each of which "hid" one reward. Retrieving a reward depleted that location and monkeys continued selecting squares until they found all rewards. The optimal strategy is to remember chosen locations and choose each square once. Unlike the inactivation study, monkeys with hippocampal damage were as accurate as controls regardless of retention interval. Critically, we found no evidence that the groups used different strategies, as measured by learning rates, spatial search biases, perseverative win‐stay errors, or inter‐choice distance. This discrepancy between the effect of inactivations and lesions may result from off‐target effects of inactivations or as‐yet‐unidentified differences between the physical and computerized tasks. Combined with previous evidence that hippocampal damage impairs navigational memory in monkeys, this evidence constrains the role of the hippocampus in spatial memory as being critical for navigational tests that likely involve allocentric spatial memory but not nonnavigational tests that likely involve egocentric spatial memory. [ABSTRACT FROM AUTHOR]

In recent years, the field has reached an impasse between models suggesting that the hippocampus is fundamentally involved in spatial processing and models suggesting that the hippocampus automatically encodes all dimensions of experience in the service of memory. Here, we consider key conceptual issues that have impeded progress in our understanding of hippocampal function, and we review findings that establish the scope and limits of hippocampal involvement in navigation and memory. We argue that space and time serve as a primary scaffold to break up experiences into specific contexts, and to organize multimodal input that is to be associated within a context. However, the hippocampus is clearly capable of incorporating additional dimensions into the scaffold if they are determined to be relevant in the event‐defined context. Conceiving of the hippocampal representation as constrained by immediate task demands—yet preferring axes that involve space and time—helps to reconcile an otherwise disparate set of findings on the core function of the hippocampus. [ABSTRACT FROM AUTHOR]

The spatial location of an object can be represented in two frames of reference: egocentric (relative to the observer's body or body parts) and allocentric (relative to another object independent of the observer). The object positions relative to the two frames can be either congruent (e.g., both left or both right) or incongruent (e.g., one left and one right). Most of the previous studies, however, did not discriminate between the two types of spatial conflicts. To investigate the common and specific neural mechanisms underlying the spatial congruency effect induced by the two reference frames, we adopted a 3 (type of task: allocentric, egocentric, and color) × 2 (spatial congruency: congruent vs. incongruent) within-subject design in this fMRI study. The spatial congruency effect in the allocentric task was induced by the task-irrelevant egocentric representations, and vice versa in the egocentric task. The nonspatial color task was introduced to control for the differences in bottom-up stimuli between the congruent and incongruent conditions. Behaviorally, significant spatial congruency effect was revealed in both the egocentric and allocentric task. Neurally, the dorsal-medial visuoparietal stream was commonly involved in the spatial congruency effect induced by the task-irrelevant egocentric and allocentric representations. The right superior parietal cortex and the right precentral gyrus were specifically involved in the spatial congruency effect induced by the irrelevant egocentric and allocentric representations, respectively. Taken together, these results suggested that different subregions in the parieto-frontal network played different functional roles in the spatial interaction between the egocentric and allocentric reference frame. Hum Brain Mapp 38:2112-2127, 2017. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Our brains represent the position of a visual stimulus egocentrically, in either retinal or craniotopic coordinates. In addition, recent behavioral studies have shown that the stimulus position is automatically represented allocentrically relative to a large frame in the background. Here, we investigated neural correlates of the 'background coordinate' using an fMRI adaptation technique. A red dot was presented at different locations on a screen, in combination with a rectangular frame that was also presented at different locations, while the participants looked at a fixation cross. When the red dot was presented repeatedly at the same location relative to the rectangular frame, the fMRI signals significantly decreased in the right precuneus. No adaptation was observed after repeated presentations relative to a small, but salient, landmark. These results suggest that the background coordinate is implemented in the right precuneus. [ABSTRACT FROM AUTHOR]

ABSTRACT Place cells are a fundamental component of the rodent navigational system. One intriguing implication of place cells is that humans, by extension, have 'map-like' (or GPS-like) knowledge that we use to represent space. Here, we review both behavioral and neural studies of human navigation, suggesting that how we process visual information forms a critical component of how we represent space. These include cellular and brain systems devoted to coding visual information during navigation in addition to a location coding system similar to that described in rodents. Together, these findings suggest that while it is highly useful to think of our navigation system involving internal 'maps,' we should not neglect the importance of high-resolution visual representations to how we navigate space. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Posterior parahippocampal gyrus (PPHG) is strongly involved during scene recognition and spatial cognition. How PPHG electrophysiological activity could underlie these functions, and whether they share similar timing mechanisms is unknown. We addressed this question in two intracerebral experiments which revealed that PPHG neural activity dissociated an early stimulus-driven effect (>200 and <500 ms) and a late task-related effect (>600 and <800 ms). Strongest PPHG gamma band (50-150 Hz) activities were found early when subjects passively viewed scenes (scene selectivity effect) and lately when they had to estimate the position of an object relative to the environment (allocentric effect). Based on single trial analyses, we were able to predict when patients viewed scenes (compared to other visual categories) and when they performed allocentric judgments (compared to other spatial judgments). The anatomical location corresponding to the strongest effects was in the depth of the collateral sulcus. Our findings directly affect current theories of visual scene processing and spatial orientation by providing new timing constraints and by demonstrating the existence of separable information processing stages in the functionally defined parahippocampal place area. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Aims To apply social network analysis ( SNA) to investigate whether frequency and severity of gambling problems were associated with different network characteristics among friends, family and co-workers is an innovative way to look at relationships among individuals; the current study was the first, to our knowledge, to apply SNA to gambling behaviors. Design Egocentric social network analysis was used to characterize formally the relationships between social network characteristics and gambling pathology. Setting Laboratory-based questionnaire and interview administration. Participants Forty frequent gamblers (22 non-pathological gamblers, 18 pathological gamblers) were recruited from the community. Measurements and Findings The SNA revealed significant social network compositional differences between the two groups: pathological gamblers ( PGs) had more gamblers, smokers and drinkers in their social networks than did non-pathological gamblers ( NPGs). PGs had more individuals in their network with whom they personally gambled, smoked and drank than those with who were NPG. Network ties were closer to individuals in their networks who gambled, smoked and drank more frequently. Associations between gambling severity and structural network characteristics were not significant. Conclusions Pathological gambling is associated with compositional but not structural differences in social networks. Pathological gamblers differ from non-pathological gamblers in the number of gamblers, smokers and drinkers in their social networks. Homophily within the networks also indicates that gamblers tend to be closer with other gamblers. This homophily may serve to reinforce addictive behaviors, and may suggest avenues for future study or intervention. [ABSTRACT FROM AUTHOR]

Dysfunction of the neostriatum, a primary feature of several neurodegenerative disorders, including Parkinson's disease and Huntington's disease, has been found to result in impaired localisation of, and reaction to, contralateral stimuli. On the basis of previous findings, it is hypothesised that, with increasing eccentricity of the response option, striatal cell loss may impair response localisation at the furthest levels of eccentricity, whereas dopamine (DA) depletion may not impact adversely upon responses executed in this extrapersonal space. In order to elucidate more fully the function of the striatum, the present study examined the differential impact of unilateral DA depletion or excitoxic lesion on response execution in ipsilateral and contralateral space at up to four levels of eccentricity. The results confirmed that, after both types of striatal dysfunction, the sensory ability to detect stimuli remains intact, whereas the ability to direct responses in absolute contralateral space is impaired. Distinct differences in the profiles of impairment were, however, evident, with a marked increase in response omissions observed after DA depletion, which may reflect decreased motivational processing, and recovery of function observed in rats with excitotoxic lesions, which suggests the ability to re-learn. Furthermore, the data demonstrate that, after cell loss, responding in near contralateral space is controlled by competing striata, whereas responding in extrapersonal space relies on the contralateral hemisphere. These results have implications for understanding the role of the striatum in egocentrically defined response localisation, as well as for unravelling the behavioural impact of striatal cell loss or aberrant DA transmission observed in neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

The present study investigated the brain dynamics accompanying spatial navigation based on distinct reference frames. Participants preferentially using an allocentric or an egocentric reference frame navigated through virtual tunnels and reported their homing direction at the end of each trial based on their spatial representation of the passage. Task-related electroencephalographic (EEG) dynamics were analyzed based on independent component analysis (ICA) and subsequent clustering of independent components. Parietal alpha desynchronization during encoding of spatial information predicted homing performance for participants using an egocentric reference frame. In contrast, retrosplenial and occipital alpha desynchronization during retrieval covaried with homing performance of participants using an allocentric reference frame. These results support the assumption of distinct neural networks underlying the computation of distinct reference frames and reveal a direct relationship of alpha modulation in parietal and retrosplenial areas with encoding and retrieval of spatial information for homing behavior. [ABSTRACT FROM AUTHOR]

This report addresses phylogenetic variation in a spatial skill that underlies tool use: aligning objects to a feature of a surface. Fragaszy and Cummins-Sebree's [Behavioral and Cognitive Neuroscience Reviews 4:282-306, 2005] model of relational spatial reasoning and Skill Development and Perception-Action theories guided the design of the study. We examined how capuchins and chimpanzees place stick objects of varying shapes into matching grooves on a flat surface. Although most individuals aligned the long axis of the object with the matching groove more often than expected by chance, all typically did so with poor precision. Some individuals managed to align a second feature, and only one (a capuchin monkey) achieved above-chance success at aligning three features with matching grooves. Our findings suggest that capuchins and chimpanzees do not reliably align objects along even one axis, and that neither species can reliably or easily master object placement tasks that require managing two or more spatial relations concurrently. Moreover, they did not systematically vary their behavior in a manner that would aid discovery of the affordances of the stick-surface combination beyond sliding the stick along the surface (which may have provided haptic information about the location of the groove). These limitations have profound consequences for the forms of tool use we can expect these individuals to master. Am. J. Primatol. 73:1012-1030, 2011. © 2011 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The retrosplenial cortex is seen as a convergence point for different classes of spatial cue, yet aside from allocentric processing, little is known about other cue types that depend on the integrity of this area. Rats with bilateral retrosplenial cortex lesions were, therefore, trained on a sequence of reinforced spatial alternation tasks designed to isolate different spatial strategies. Using a standard T-maze alternation procedure, which could be solved using multiple strategies, only a marginal lesion effect was observed. Next, by using two T-mazes set side-by-side in the light, and then the dark, it was possible to examine alternation around a fixed bearing (direction alternation). Retrosplenial cortex lesions only disrupted the latter (direction alternation) condition. Direction alternation is of particular interest as it presumably taxes head-direction information, and so provides a way of behaviourally assessing the contribution of this navigation system. Finally, rats were tested on a spatial working memory task in a radial-arm maze. A retrosplenial lesion deficit appeared when the maze was rotated mid-trial, as repeatedly found in previous studies. The pattern of findings in the present study strongly indicates that retrosplenial cortex lesions impair the use of direction cues for alternation, in addition to previously established impairments for allocentric-based navigation and path integration. [ABSTRACT FROM AUTHOR]

Recent advances in the understanding of spatial cognition are reviewed, focusing on memory for locations in large-scale space and on those advances inspired by single-unit recording and lesion studies in animals. Spatial memory appears to be supported by multiple parallel representations, including egocentric and allocentric representations, and those updated to accommodate self-motion. The effects of these representations can be dissociated behaviorally, developmentally, and in terms of their neural bases. It is now becoming possible to construct a mechanistic neural-level model of at least some aspects of spatial memory and imagery, with the hippocampus and medial temporal lobe providing allocentric environmental representations, the parietal lobe egocentric representations, and the retrosplenial cortex and parieto-occipital sulcus allowing both types of representation to interact. Insights from this model include a common mechanism for the construction of spatial scenes in the service of both imagery and episodic retrieval and a role for the remainder of Papez's circuit in orienting the viewpoint used. In addition, it appears that hippocampal and striatal systems process different aspects of environmental layout (boundaries and local landmarks, respectively) and do so using different learning rules (incidental learning and associative reinforcement, respectively). [ABSTRACT FROM AUTHOR]