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PubMed1995

Spatial concepts and perception of physical and diagrammed scenes.

The accessibility of objects in mental spatial frameworks depends on their relation to the spatial axes of the world and people's typical interactions with space. The current study investigated perception of space. Subjects viewed either a physical model of a person surrounded by objects (Exp. 1) or diagrams of scenes (Exp. 2). Subjects named objects at directions from their own external perspective. For physical scenes, subjects were faster to name objects at Above/Below locations, followed by Front/Behind locations, followed by Left/Right locations. This finding indicates that subjects used spatial frameworks to locate objects perceptually. For diagrams, response times to name objects did not conform to this pattern, perhaps because the spatial axes of a diagram do not correspond to stable spatial axes of the world.

Adolescent↗
PubMed2006

Neuronal implementation of hippocampal-mediated spatial behavior: a comparative evolutionary perspective.

The hippocampal formation (HF) of mammals and birds plays a strikingly similar role in the representation of space. This evolutionarily conserved property, however, belies the contrasting spatial ecology of animals such as rats and homing pigeons, differing spatial ecologies that should have promoted the evolution of group-specific adaptations to the HF representation of space. However, the spatial response properties of pigeon and rat HF neurons reveal surprising similarity in the contribution of position, direction, and trajectory toward explaining spatial variation in firing rate. By contrast, the asymmetrical distribution of neuronal response properties in the left and right HF of homing pigeons, but not rats, indicates a difference in network organization. The authors propose that hippocampal evolution may be characterized by inertia with respect to changes in the basic spatial elements that determine the response properties of neurons but considerable plasticity in how the neuronal response elements are organized into functional networks.

Animals↗
PubMed2000

The scopolamine-induced impairment of spatial cognition parallels the acetylcholine release in the ventral hippocampus in rats.

We investigated the relationship between the induction of spatial cognition impairment in the 8-arm radial maze task and regional changes (ventral hippocampus (VH), dorsal hippocampus, frontal cortex, and basolateral amygdala nucleus) in brain acetylcholine (ACh) release using microdialysis in rats treated with muscarinic (M) receptor antagonists. In a behavioral study, two M1 antagonists, scopolamine (0.5 mg/kg, i.p. and 20 microg, i.c.v.) and pirenzepine (80 microg, i.c.v.), but not an M2 antagonist, AF-DX116 (40-80 microg, i.c.v.), disrupted spatial cognition in the 8-arm radial maze task. In brain microdialysis with Ringer's solution containing 0.1 mM eserine sulfate, scopolamine and AF-DX116, but not pirenzepine, increased ACh release in the VH. Moreover, in the bilateral injection of scopolamine (2 microg/side), the VH and dorsomedial thalamus nucleus were important regions for scopolamine-induced impairment of spatial cognition. A simultaneous determination of the behavioral changes revealed that scopolamine (0.5 mg/kg, i.p.) markedly decreased the ACh contents and also increased the ACh release in all regions tested. Especially, the changes in the ACh release of the VH closely paralleled the induction of the scopolamine-induced impairment of spatial cognition. These results suggest that the blocking balance between M1 and M2 muscarinic receptor in the VH therefore plays a major role in the spatial cognition impairment induced by scopolamine in the 8-arm radial maze task.

Acetylcholine↗
PubMed1976

Relationship between spatial density and sensory overload, personal space, and systolic and diastolic blood pressure.

Selected effects of high spatial density were investigated with 26 boys, serving as their own controls and undergoing alternate confinements in high and relatively low spatial density. Measured effects were changes in minimal aversion threshold values of white sound, projective measures of desire to alter room size, and systolic and diastolic blood pressure. High spatial density increased systolic and diastolic blood pressure and projective measures of desire to alter room size but did not affect minimal aversion threshold values. Semi-projective measures of personal space requirements were obtained prior to experimental trials. Analysis showed a significant interaction of minimal aversion threshold values with requirements for personal space; the minimal aversion threshold values of subjects requiring large personal space tended to decrease following confinement under high spatial density. The interaction of personal space with projected measures of desire to alter room size was not significant. High spatial density may, then, exert adverse effects on blood pressure and may induce sensory overload conditions in individuals requiring large personal space.

Adolescent↗
PubMed2003

Egocentric organization of spatial activities in imagined navigation.

Studies on spatial frameworks suggest that the way we locate objects in imagined environments is influenced by the physical and functional properties of the world and our body. The present study provides evidence that such an influence also characterizes imagined navigation. In Experiment 1, participants followed spatial directions to construct an imagined path, while either keeping constant or updating their orientation at each step. A pattern of step times diagnostic of spatial frameworks was obtained in the updated-orientation but not in the constant-orientation condition. In Experiment 2, participants performed the updated-orientation condition with two levels of external support for the reference frame being used. Step times conformed to the predictions of spatial frameworks in both conditions. Both experiments also provided support that the processes involved in imagined navigation exhibit the operator-operand dynamics of other mental skills previously documented in the mental arithmetic domain. These results reinforce Piaget's (1954) notion that spatial displacements and integer arithmetic share a set of structural characteristics

Female↗
PubMed2001

Preferences for ascending and descending hierarchical organization in spatial communication.

People prefer to order spatial information in a hierarchy of decreasing size of spatial unit when giving directions for finding objects and in a hierarchy of increasing size of spatial unit when providing descriptions of object locations (Plumert, Carswell, DeVet, & Ihrig, 1995). In five experiments, we examined whether people have a preference for ascending or descending organization when the task does not involve conveying spatial information to others. In Experiments 1-3, people learned the locations of objects in a model house and then verified statements describing those locations. People verified statements faster when spatial units were organized in an ascending (i.e., small to large) than in a descending (i.e., large to small) or random order. In Experiment 4, people first performed a sentence verification task and afterward wrote down directions for finding the objects. People again exhibited a preference for ascending organization in the verification task but exhibited a preference for descending organization when giving directions for finding the same objects. Experiment 5 demonstrated that the ascending advantage was not due to the link between the object and small landmark. Discussion focuses on the role of pragmatics and memory retrieval in preferences for ascending versus descending hierarchical organization.

Choice Behavior↗
PubMed2026

A Practical Workflow for Spatial Transcriptomics Data Analysis: From Data Acquisition to Advanced Analyses.

Spatial transcriptomics (ST) profiles genome-wide gene expression while preserving the two-dimensional spatial context of mRNA molecules within tissue sections, enabling studies of tissue architecture and microenvironment-associated biology. However, ST analysis remains challenging because data import, quality control, integration, deconvolution, spatial statistics, and visualization often require multiple software environments and reproducible parameter choices. This protocol presents a practical computational workflow for public ST datasets in R, beginning with data acquisition and software setup and proceeding through Seurat-based data loading, quality control, normalization, multi-sample integration, clustering, and spatially variable gene analysis. The workflow then applies complementary deconvolution strategies, including reference-guided SPOTlight analysis and unsupervised STdeconvolve topic modeling, followed by Giotto-based spatial cell-cell communication analysis and interactive region-of-interest (ROI) selection using a custom Python Dash application. By emphasizing script-based execution, explicit parameter rationales, expected outputs, and troubleshooting checkpoints, the protocol provides an adaptable framework for standard array-based ST datasets and related platforms after dataset- and platform-specific parameter evaluation.

Spatial Transcriptomics↗
PubMed2000

[Spatial memory and hippocampus in aves].

The avian hippocampus, that locates in the posterior part of dorsomedial telencephalon, is considered to be a mammalian hippocampus homologue. The studies of connection, distribution of transmitters, and development of the avian hippocampus all support the homology. Food storing birds have large capacity of spatial memory and have a big hippocampus in comparison to non-storing species. The food-storing birds do not have good memory in general but have good memory specialized to the spatial tasks. The correlation between the volume of the hippocampus and behavior other than food storing but needs spatial memory is also suggested. The hippocampal damages cause deficits in spatial learning especially those using a maze but do not impair non-spatial learning tasks. These studies suggest that the avian hippocampus share a similar function with the mammalian hippocampus, especially that of rodents.

Animals↗
PubMedDate not supplied

[Spatial learning and the hippocampus].

INTRODUCTION: Since publication of the book The hippocampus as a cognitive map by O'Keefe and Nadel in 1978, several theoretical and experimental works have supported the participation of the hippocampus in rodents in spatial processing. Since then, great advances have been made into understanding the potential role of the hippocampus in learning and memory processes, relegating a secondary role to the hypothesis that, in rodents, the hippocampus is restricted to the formation of a cognitive map. DEVELOPMENT: In this work, different forms of spatial navigation are analyzed (taxis, cartographic and route integration-based navigation) on a psychological and neurobiological level. The spatial function of the hippocampus proposed by O'Keefe and Nadel is discussed but a more general model is chosen that explains the function of the hippocampus in mammals, i.e. a model of relational memory. Therefore, in the context of relational memory we attempt to explain the different forms of spatial memory in rodents and present the most relevant experimental data that support a critical role for the hippocampus in this kind of memory. CONCLUSIONS: The studies reviewed in this work support an important role for the hippocampus in spatial processing. However, this does not appear to be its sole function and it possibly operates more widely also participating in relational memory.

Animals↗
PubMedDate not supplied

[Is the hippocampus necessary for spatial learning?].

OBJECTIVE: A variety of findings, mainly based on lesion studies, have led to the proposal that the hippocampus is a necessary component of the neural system supporting spatial learning. However, recent research is challenging this classic view. The goal of this review is to discuss and integrate these new data with previous findings. DEVELOPMENT: Several studies performed in our lab have shown that hippocampal lesions do not affect the acquisition of a place response if a special training procedure is used. Nevertheless, the way how this special training method overcome the learning deficit is not well known. In this review we propose that hippocampal damage produces several non spatial deficit, being one of them a deficit in behavioral flexibility. Thus, it is possible that our special training procedure encourage behavioral flexibility and variability in response in lesioned subjects, which would allow a significant improvement in the learning of the spatial task. CONCLUSION: The data discussed in this review suggest that the hippocampus is not completely necessary for the learning of a place. It would be the sum of spatial and non spatial deficit ('hippocampal syndrome') which would produce the acquisition deficit typically seen in hippocampal rats when a traditional training method is used.

Amnesia↗
PubMed1991

[Who is a migrant? Problems of documenting and defining spatial mobility in developing countries].

"Increasingly uneven spatial population distribution, especially in developing countries, has brought about a growing need for better statistical information on the extent of the various forms of spatial mobility during the [1980s] and their determinants and consequences....The main issues discussed in this paper are...the problems of defining and measuring spatial mobility in general as well as [reviewing] the types of mobility-related questions in censuses, their strengths and weaknesses, and the possibilities of evaluation of the collected data. Finally, alternative concepts for measuring spatial mobility are discussed which could help to gather information on non-permanent forms of spatial mobility, an issue of growing importance for the developing world." (SUMMARY IN ENG)

Data Collection↗
PubMed2004

Early-life nutritional environment and spatial navigation in the water shrew, Sorex palustris (Insectivora).

Studies were conducted to study the effects of early-life nutritional environment on spatial navigation ability in the water shrew (Sorex palustris), as well as to provide information on life history traits and husbandry. The mean longevity of males and females in captivity was 652.3 +/- 33.8 SD and 616.2 +/- 22.5 days, respectively. Litter sizes ranged from 5 to 8 and neonatal mass ranged from 0.71 to 0.83 g. Spatial navigation was examined by use of the Morris water apparatus, where animals were required to locate the position of an escape platform in a circular tank of water. The platform was visible (proximal cue version of the task) in some tests. In other tests it was hidden beneath the surface (distal cue version) by making the water opaque using a non-toxic white dye. The tank was divided into 4 quadrants and the position of the plafform in any quadrant could be fixed for any subject or varied between subjects. Early-life under-nutrition was achieved by maintaining some shrews on a restricted diet (received half the amount of food as did controls). Under-nutrition was found to have an adverse effect on spatial navigation. Regardless of nutritional status, shrews were able to locate a hidden plafform that was placed at the center of a given quadrant more rapidly (escape latency) when it was visible (44 to 69 sec) than when it was hidden (83 to 164 sec). Results also showed that these shrews utilize both proximal and distal cues in this spatial task. Control subjects spent more time at a location where the platform had been in a previous test (69% of the trial period) than their undernourished counterparts (45 to 51%). This is the first experimental analysis of spatial navigation and the effects of early-life under-nutrition on this task, for S. palustris.

Analysis of Variance↗
PubMed2006

[Effect of citicoline on spatial learning and memory of rats after focal cerebral ischemia].

OBJECTIVE: To investigate the effects of citicoline on spatial learning and memory of rats after focal cerebral ischemia. METHODS: The rats were randomly divided into sham-operation group, ischemia control group and citicoline group. In the later two groups, focal cerebral ischemia model was established by introducing an intraluminal filament into the left middle cerebral artery, and citicoline (500 mg/kg) or 0.9% NaCl was administered intraperitoneally once a day for 2 weeks after the operation. The rats in the sham-operation group were not subjected to middle cerebral artery occlusion (MCAO) with intraluminal filament. The spatial learning and memory functions of the rats were evaluated by Morris water maze test 15 days after MCAO for 5 days. RESULTS: The rats in ischemia control group exhibited serious spatial learning and memory deficits in both place navigation test and spatial probe test. In the former test, the mean escape latency of citicoline-treated rats were significantly shorter than that of ischemia control rats (P<0.01), and in the latter test significant diffidence was noted between citicoline and ischemia control groups in the percentage time spent in the former platform quadrant and frequency of crossing the former platform (P<0.05). CONCLUSION: Citicoline can improve the spatial learning and memory function of rats after focal cerebral ischemia.

Animals↗
PubMed1986

Cholinergic septal grafts into the hippocampal formation improve spatial learning and memory in aged rats by an atropine-sensitive mechanism.

Behaviorally impaired old rats were selected from a population of 75 21- to 23-month-old rats on the basis of the place-investigated abilities in the Morris' water-maze task. After the pretransplant test, half of the old impaired rats received bilateral intrahippocampal cell suspension grafts prepared from the fetal septal-diagonal band region, which is rich in developing cholinergic neurons; the other half were left as sham-operated controls. Twelve weeks after grafting, the rats were retested in the water-maze using alternating cue-navigation and place-navigation trials (i.e., with visible or nonvisible escape platform). While the old impaired controls had deteriorated further between the 2 tests and showed poor retention of the pretransplant performance level, the grafted rats were significantly improved in comparison with both their pretransplant performance and the performance of the old impaired controls in the posttransplant test. The graft-induced effect was due both to an improved retention of the performance level acquired in the test performed prior to transplantation surgery, and to an improved acquisition of spatial memory of the escape platform site during the posttransplant test week (measured as an improved focusing of search over the platform site after platform removal). The acetylcholine esterase inhibitor physostigmine had no or only marginal effects on the performance of any of the young or aged rat groups. By contrast, the recovered navigational abilities and spatial memory in the grafted animals were completely abolished after administration of the muscarinic receptor antagonist atropine. A similar atropine-sensitivity was seen in behaviorally nonimpaired aged rats but not in the well-trained young control rats. The results show that cholinergic septal grafts, implanted into the hippocampal formation, improved spatial learning in the impaired aged rats primarily, or perhaps exclusively, by a recovery of the rats' ability to use spatial cues for place-navigation in the water-maze, while other aspects of the performance deficits in the water-maze task in the aged rats were left unaffected by the septal grafts. On the basis of parallel morphological studies, it is proposed that the effects of the septal grafts on the spatial learning impairments in the aged rats are critically dependent on the direct action of cholinergic neurons in the grafts via synapses formed onto neuronal elements in the host by their ingrowing axons.

Aging↗
PubMed1997

Differential activation of the caudate nucleus in primates performing spatial and nonspatial working memory tasks.

The caudate nucleus is part of an anatomical network subserving functions associated with the dorsolateral prefrontal cortex (DLPFC). The aim of the present study was to investigate whether the metabolic activity in the striatum reflects specific changes in working memory tasks, which are known to be dependent on the DLPFC, and whether these changes reflect the topographic ordering of prefrontal connections within the striatum. Local cerebral glucose utilization (LCGU) rates were assessed in the striatum by the 14C-2-deoxyglucose method in monkeys that performed a spatial (delayed spatial alternation), a nonspatial (delayed object alternation) visual working memory task, or tasks that did not involve working memory, i.e., a visual pattern discrimination or sensorimotor paradigm. The results show a topographic segregation of activation related to spatial and nonspatial working memory, respectively. The delayed spatial alternation task increases LCGU rates bilaterally by 33-43% in the head of the caudate nucleus, where efferents from the dorsolateral prefrontal cortex project most densely. The delayed object alternation task enhances LCGU rates bilaterally by 32-37% in the body of the caudate nucleus, which is innervated by the temporal cortex. The visual pattern discrimination task similarly activated the body of the caudate, but in a smaller region and only in the right hemisphere. These findings provide the first evidence for metabolic activation of the caudate nuclei in working memory, supporting the role of this nucleus as a node in a neural network mediating DLPFC-dependent working memory processes. The double dissociation of activation observed suggests an anatomical and functional segregation of cortico-striatal circuits subserving spatial and nonspatial cognitive operations.

Animals↗
PubMed1997

The role of vitronectin in the attachment and spatial distribution of bone-derived cells on materials with patterned surface chemistry.

In recent years a central objective of tissue engineering has been understanding the interaction of cells with biomaterial surfaces. In this study we examined the protein adsorption events necessary to control the attachment and the subsequent spatial distribution of bone-derived cells exposed to chemically modified surfaces. Silane chemistry and photolithography techniques were used to create substrates with alternating regions of an aminosilane, N-(2-aminoethyl)-3-aminopropyl-trimethoxysilane (EDS), along side an alkylsilane, dimethyldichlorosilane (DMS), on quartz surfaces. Sera depleted of fibronectin (Fn), vitronectin (Vn), or both were used to determine if these proteins were necessary for the initial attachment and spatial distribution of bone-derived cells exposed to modified surfaces in vitro. The kinetics and mechanisms of the spatial distribution of cells were examined using light microscopy and digital image acquisition and subsequently were analyzed. Compared to complete serum, the use of serum depleted of fibronectin with vitronectin included had minimal effect on the cell attachment, spreading, and spatial distribution on the EDS regions of the surface. However, the use of serum depleted of vitronectin with or without fibronectin included resulted in greatly reduced cell attachment and spreading. Thus the presence of vitronectin was required for the attachment, spreading, and spatial distribution of bone-derived cells exposed to EDS/DMS-patterned surfaces.

Adsorption↗
PubMed1998

Spatial mapping takes time.

The experiment tested the prediction that spatial mapping takes time and asked whether time use is reflected in the overt behavior of a performing animal. The study examines this question by exploiting the expected behavioral differences of control rats and rats with hippocampal formation damage induced with fimbria-fornix (FF) lesions on a spatial navigation task. Previous studies have shown that control rats use a mapping strategy, in which they use the relative positions of environmental cues to reach places in space, whereas FF rats use a cue-based strategy, in which they are guided by a single cue or their own body orientation. Therefore, control and FF rats were overtrained on a complex foraging task in which they left a burrow to retrieve eight food pellets hidden around the perimeter of a circular table. The control rats retrieved the food pellets in order of their distance from the burrow, took direct routes to the food, and made few errors, all of which suggested they used a spatial strategy. The FF rats were less likely to retrieve food as a function of its distance, took a circular path around the perimeter of the table, and made many errors, suggesting they used a cue-based strategy. Despite taking shorter routes than the FF rats, the control rats had proportionally slower response speeds. Their slow response speeds support the hypothesis that spatial mapping takes time and that mapping time is reflected in behavior. The results are discussed in relation to their relevance to spatial mapping theory, hippocampal function, and the evolution of foraging strategies.

Animal Feed↗
PubMedDate not supplied

Multivariate spatial models for event data.

This paper describes how estimates made for event rates in small areas may be enhanced through spatial modelling of the data - taking the geographical location of each area into account - and through the addition of further information from each area. In particular we consider the use of spatial models to predict more than one outcome simultaneously. This is done by writing the spatial model as a multi-level model and subsequently enhancing this to encompass a multivariate data structure; estimates are obtained using iterative generalized least squares in the software package MLwiN. The example given considers mortality due to two causes--neoplasms and circulatory disease--in 143 postcode sectors in Greater Glasgow Health Board, Scotland. In addition, a measure of socio-economic deprivation is available for each area. Correlations between causes within areas, between areas within causes and between areas and causes are quantified, as are the relative contributions of the heterogeneous and spatial parts of the model. The results suggest a tendency for there to be pockets with high mortality rates due to neoplasms, whilst mortality due to circulatory disease follows a much smoother pattern. After taking deprivation into account, the spatial component accounts for just 19 per cent of the variation in the mortality due to neoplasms in Greater Glasgow but 66 per cent of the mortality due to circulatory disease.

Age Factors↗