Memory for the spatial layout of the everyday physical environment: Factors affecting rate of acquisition

That a memory representation of the spatial layout of a large-scale environment may be acquired very fast was shown in two experiments in which subjects (48 undergraduates and high-school students) were taken on tours through a residential area with which they were unfamiliar. Memory for the path traversed was almost perfect after the first trial, as indicated by almost perfect recall of the order in which a number of designated landmarks had been passed. Memory for the locations of the same landmarks appeared to reach an asymptotic level after the second of three trials. The memory representation of the locations were however not perfectly accurate, thus the asymptotic level might have been an acquisition plateau. The rate of acquisition was slightly faster for subjects driven in a car slowly through the area than for those who walked the same path. Men tended to improve slightly faster than women if they were driven by car but there were no other sex differences. Finally, the acquired memory representation appeared to be resistant to forgetting. Re-learning after a one-week retention interval was faster and rate of learning was not negatively affected whether the trials were massed or distributed with one week in between. The results are discussed in terms of hypotheses concerning the order in which different types of information about spatial layouts (landmarks, paths, and locations) are acquired. The bearing of the results on the question of why memory representations of the spatial layout are often found to be distorted is also discussed.     

Besides navigation accuracy: Gender differences in strategy selection and level of spatial confidence

A virtual version of the reorientation task was employed to test new behavioral measures of navigation strategies and spatial confidence within a gender-fair assessment approach. The results demonstrated that, from a behavioral point of view, women had lower level of spatial confidence than men regardless of level of accuracy. Moreover, the way men and women selected spatial strategies depended on the arrangement of spatial cues within the environment. In other terms women relied on landmarks under specific conditions compatible with an adaptive combination/associative model of spatial orientation. Finally, the present study emphasized the importance to assess gender differences taking into account specific affective variables and information selection processing, beyond accuracy.     

Experimenter instructions as a mediator in the effects of culture on mapping one's neighborhood

In study 1 children, aged 6 and 12 years from southern India and mid-west USA were asked to construct a map of the neighborhoods around their schools. Performance on map making was measured in three ways: (1) the number of features depicted; (2) cognitive maturity in map representation (using Piaget's stages) and (3) furthest point represented. Significant main effects for performance was found for cultural context. Indian children depicted more features than American children while American children had more coordinated maps and depicted features further away from their school.In the second experiment, a different sample of same aged children in the same region of the USA and India were given differing instructions about the purpose of the mapping task. It was found that children tailored their maps for the purpose for which they had to construct it. The cultural differences in Piagetian stages disappeared; Indian children continued to exhibit a more intimate knowledge of their neighborhoods while American children depicted landmarks further away.     

A MULTIVARIATE ANALYSIS OF SERIAL MURDERERS'' DISPOSAL SITE LOCATION CHOICE

The application of environmental psychology principles and findings to the work of criminal investigators is gaining ground. This paper presents one particular application of these principles to the study of those very rare criminals, serial killers. An environmental psychology perspective looks on the rational processes that may underlie these disturbing and highly emotive crimes. For, although the murders committed by serial killers may not be considered rational, but rather a consequence of heightened emotion and lack of impulse control, environmental psychology hypotheses predict that their choice of disposal site location may be guided by a recognisable rationality. Support for this rationality would be evident through their spatial patterns of disposal locations, but these spatial patterns themselves would vary depending on the range over which the offender was operating. It was therefore hypothesised that their spatial patterns would reflect the importance of a) the centrality of the home location for determining the disposal site locations, b) the relevance of maintaining distance between sequential disposal site locations themselves. Further, c) the nature of the influences of home and sequence would vary with the size of the area over which the offender disposed of his victims' bodies.The hypotheses were tested by examining three sub-sets of a sample of 120 American serial murderers, each sub-set travelling a different average distance from their homes to their crimes. The Multidimensional Scaling Procedure, Smallest Space Analysis (SSA-I) was used in order to examine the trends across the distances between each disposal site and every other and their distances from the offender's homes. A three dimensional space was used so that the ‘dimension’ of temporal sequence could be revealed as well as the two dimensions of geographical distances. All hypotheses were supported. Firstly, the home was central to the SSA disposal patterns for each of the three sub-sets. Secondly, the location of each subsequent disposal location tended to be in a different direction from that immediately prior to it. However, thirdly, this sequential process was strongest for the sub-set of 36 offenders who travelled on average less than 10 km and weakest for those 40 offenders who travelled on average greater than 30 km. The implications these results have for modelling offenders' geographical behaviour are discussed.     

A spatial model approach for assessing windbreak growth and carbon stocks

Agroforestry, the deliberate integration of trees into agricultural operations, sequesters carbon (C) while providing valuable services on agricultural lands. However, methods to quantify present and projected C stocks in these open-grown woody systems are limited. As an initial step to address C accounting in agroforestry systems, a spatial Markov random field model for predicting the natural logarithm (log) of the mean aboveground volume of green ash ( Marsh.) within a shelterbelt, referred to as the log of aboveground volume, was developed using data from an earlier study and web-available soil and climate information. Windbreak characteristics, site, and climate variables were used to model the large-scale trend of the log of aboveground volume. The residuals from this initial model were correlated among sites up to 24 km from a point of interest. Therefore, a spatial dependence parameter was used to incorporate information from sites within 24 km into the prediction of the log of the aboveground volume. Age is an important windbreak characteristic in the model. Thus, the log of aboveground volume can be predicted for a given windbreak age and for values of other explanatory variables associated with a site of interest. Such predictions can be exponentiated to obtain predictions of aboveground volume for windbreaks without repeated inventory. With the capability of quantifying uncertainty, the model has the potential for large regional planning efforts and C stock assessments for many deciduous tree species used in windbreaks and riparian buffers once it is calibrated.     

The role of cognitive maps in spatial decisions

The traveling salesman's problem, in which one decides which order between n locations minimizes total travel distance, was used as a laboratory analogue of spatial decisions in large-scale environments. In an experiment in which university students were observed while solving this problem, a group who received numerical information about distances between locations was found to minimize local distances rather than total distance, that is, to choose first the closest location from the starting location, then the closest location from that chosen, and so forth. However, if a picture of the locations was presented, total distance was minimized more frequently than local distances, presumably because subjects changed their decisions which minimized local distances when they discovered spatial patterns indicating that a shorter path existed. It was also found that a picture did not always have to be presented because subjects mentally constructed a functionally equivalent spatial representation from pieces of direction and distance or only direction information. This finding was even clearer when subjects were allowed to draw pictures of the locations.     

Pointing to preschool children's spatial competence: A study in natural settings

This paper describes a series of experiments which explore the extent to which children aged three years five months to four years seven months can build a Euclidean mental representation of the environment. It was found that the children showed a higher level of spatial competence than previous research had indicated, and that their spatial ability was dependent upon the nature of the environment. Euclidean knowledge was found at all ages in a familiar environment, but especially when familiarity was brought about through self-exploration. Euclidean knowledge was least likely in a novel environment. Previous experience with the test in the familiar environments did not lead to an increase in Euclidean knowledge in the novel environment. The results are interpreted in terms of Byrne's ‘network-map’/‘vectormap’ theory of spatial knowledge.     

Pointing accuracy in children is dependent on age, sex and experience

We investigated the influence of age, sex and familiarity on spatial performance assessed with a pointing task in 84 children: 21 kindergartners, 21 first-graders, 21 fifth-graders and 21 sixth-graders. Spatial performance was assessed in the children's natural environment, their respective school or kindergarten. The children had to indicate the direction of prominent landmarks on the school campus while sitting in their classroom, drawing an arrow on a sheet of paper. Since the children had spent different amounts of time at their respective schools, experience with the environment was regarded as a covariate.Data analysis revealed significant effects for age, sex and experience. Fifth-graders aged around 10 years outperformed the younger children. Sex differences revealed male superiority at all ages. Experience with the environment was also shown to play a vital role. Children who had spent a longer time at the school were able to demonstrate better spatial knowledge by pointing more accurately towards unseen landmarks.     

Using rank-order geostatistics for spatial interpolation of highly skewed data in a heavy-metal contaminated site

The spatial distribution of a pollutant in contaminated soils is usually highly skewed. As a result, the sample variogram often differs considerably from its regional counterpart and the geostatistical interpolation is hindered. In this study, rank-order geostatistics with standardized rank transformation was used for the spatial interpolation of pollutants with a highly skewed distribution in contaminated soils when commonly used nonlinear methods, such as logarithmic and normal-scored transformations, are not suitable. A real data set of soil Cd concentrations with great variation and high skewness in a contaminated site of Taiwan was used for illustration. The spatial dependence of ranks transformed from Cd concentrations was identified and kriging estimation was readily performed in the standardized-rank space. The estimated standardized rank was back-transformed into the concentration space using the middle point model within a standardized-rank interval of the empirical distribution function (EDF). The spatial distribution of Cd concentrations was then obtained. The probability of Cd concentration being higher than a given cutoff value also can be estimated by using the estimated distribution of standardized ranks. The contour maps of Cd concentrations and the probabilities of Cd concentrations being higher than the cutoff value can be simultaneously used for delineation of hazardous areas of contaminated soils.     

Assessment of spatial variation of cesium-137 in small catchments

Surface contamination by bomb-derived and Chernobyl-derived 137Cs has been subject to changes due to physical decay and lateral transport of contaminated soil particles, which have resulted in an on-going transfer of radionuclides from terrestrial ecosystems to surface water, river bed sediments, and flood plains. Knowledge of the different sources of spatial variation of 137Cs is particularly essential for estimating 137Cs transfer to fluvial systems and for successfully applying 137Cs as an environmental tracer in soil erosion studies. This study combined a straightforward sediment redistribution model and geostatistical interpolation of point samples of 137Cs activities in soil to distinguish the effects of sediment erosion and deposition from other sources of variation in 137Cs in the small Mochovce catchment in Slovakia. These other sources of variation could then be interpreted. Besides erosion and deposition processes, the initial pattern of 137Cs deposition, floodplain sedimentation, and short-range spatial variation were identified as the major sources of spatial variation of the 137Cs inventory.     

Pattern of representation of countries in cognitive maps of the world with special reference to Africa

Although for a long time environmental psychologists have been concerned with the nature and process of environmental perception and its representation in map forms, global sketch maps have not been popular in mainstream research. Further, conceptual and theoretical insights into the subject are yet to be fully achieved; and quite significantly, comparative analysis has been limited by the concentration of research efforts in the developed countries of Europe and America. In the same vein, the challenge of clarifying the psychological, spatial and social underpinnings of cognitive maps and their contributory role in day-to-day space-related problem solving and decision-making brings to the fore the need for cross-disciplinary and across-regional studies. This paper examines the world's image from an African perspective, exploring those countries of the world that are best known to Africans and the factors responsible for the pattern of recall and representation in the maps drawn by them. Some 656 maps were collected from 13 sites in 11 countries. Analysis of the frequency of inclusion of countries was first carried out; chi-square analysis was then performed on the frequency of inclusion by level of a country's economic development, population, geographical size and relative location from Nigeria and Africa. The results from qualitative interpretation show that while images of countries may have been influenced by composite and multifaceted factors, embracing historical and cultural associations, media images and invocations, Africans, nevertheless, tended to recall nations following some descending hierarchy, with ‘developed/geographically prominent countries’, ‘we’ (i.e. Africa), ‘others’ and ‘unknown’ countries as discernible clusters. From statistical test, population and spatial size of countries, the proximity of countries to the assessors and to some extent, level of economic development, were found to be significant in accounting for the pattern of recall and representation in cognitive maps. The paper shows that in spite of the evident limitations of mental sketches they hold some promise for our understanding of cross-regional variations in the images of the world, which could be important to the building of relevant social and geographical education to foster global understanding.     

A conceptual model and empirical analysis of children's acquisition of spatial knowledge

How adults and children come to understand, represent and behave within their spatial environment are topics of great interest to geographers, psychologists, environmental planners and laypeople. Considerable research and theory has been published on these and related topics. In this paper, we will review some of what is known and theorized about spatial cognition and then consider elements of our research program on the acquisition of spatial knowledge. We focus on two intimately related topics. The first is the development of a conceptual model of the knowledge structures and processes associated with acquiring, representing and accessing knowledge of a given environment. The conceptual model forms the basis for a formal computational process model intended as a simulation of actual knowledge and performance in way finding tasks. The second emphasis is an in-depth case study of the acquisition of spatial knowledge. The case study focuses on a single child acquiring knowledge of a lengthy route through an unfamiliar suburban neighborhood. It is presented as an empirical test of certain assumptions embodied within the conceptual model.Before introducing the conceptual model and the case study, we first review the state of current theory and data on spatial cognition and identify four central issues confronting researchers in this field. This review provides a necessary context for describing and evaluating our program of research. The second section of this paper discusses elements of the conceptual model and its relationship to other formal computational models. The third section considers specific hypotheses about the acquisition and representation of spatial knowledge and tests of these hypotheses from the single in-depth case study. The final discussion section of this paper is a reconsideration of the four issues raised in the first section and necessary and proposed extensions of the current research.     

Evaluating the effects of spatial monitoring policy on groundwater quality portrayal

What size sample is sufficient for spatially sampling ambient groundwater quality? Water quality data are only as spatially accurate as the geographic sampling strategies used to collect them. This research used sequential sampling and regression analysis to evaluate groundwater quality spatial sampling policy changes proposed by California's Department of Water Resources. Iterative or sequential sampling of a hypothetical groundwater basin's water quality produced data sets from sample sizes ranging from 2.8% to 95% coverage of available point sample sites. Contour maps based on these sample data sets were compared to an original (control), mapped hypothetical data set, to determine at which point map information content and pattern portrayal are not improved by increasing sample sizes. Comparing series of contour maps of ground water quality concentration is a common means of evaluating the geographic extent of groundwater quality change. Comparisons included visual inspection of contout maps and statistical tests on digital versions of these map files, including correlation and regression products. This research demonstrated that, down to about 15% sample site coverage, there is no difference between contour maps produced from the different sampling strategies and the contout map of the original data set.     

Landmarks’ use in speech map navigation tasks

Tools for assisting human navigation, especially in-vehicle systems, have been extensively investigated. However, few studies have explored the design of speech-based over-the-phone guidance systems. This study examined the effect of landmarks' use and the effect of landmarks’ frames of reference in route instructions on navigation efficiency during map navigation tasks and satisfaction. Twenty-seven participants performed map navigation tasks using a simulated speech navigation system in three experimental conditions: instructions containing no landmarks, instructions containing landmarks located without reference to either the traveler’s body or the surrounding environment, and instructions containing landmarks located with respect to the traveler’s body. Navigation performances on maps were higher and landmarks enable participants to make fewer directional errors and find their routes more efficiently. Satisfaction levels and navigation performances were lower when instructions did not contain any landmarks. Landmarks’ frames of reference shifting turned out to be different between human-human situations previously used and human-computer situations used here.     

Tijuana Childhood Lead Risk Assessment Revisited: Validating a GIS Model with Environmental Data

The objective of this research was to determine the spatial distributions of childhood lead poisoning and soil lead contamination in urban Tijuana. The Bocco–Sanchez model of point-source emissions was evaluated in terms of validity and reliability. We compared the model's predicted vulnerable populations with observed cases of childhood lead poisoning in Tijuana, identified fixed point sources in the field, and analyzed 76 soil samples from 14 sites. The soil lead results were compared to the blood lead analyses performed on Tijuana children whose blood lead levels were ≥10 μg/dL, who reported that they did not use lead-glazed ceramics for cooking or storing food (n = 63). Using GIS, predicted vs observed risk areas were assessed by examining spatial patterns, including the distribution of cases per designated risk area. Chi-square analysis of expected vs observed values did not differ significantly at the p = 0.02 level, showing that the model was strikingly accurate in predicting the distribution of subjects with elevated blood lead. Results reveal that while point sources are significant, other sources of lead exposure are also important. The relative public health risk from exposure to lead in an urban setting may be assessed by distinguishing among sources of exposure and associating concentrations to blood lead levels. The results represent an iterative approach in environmental health research by linking environmental and human biomarker lead concentrations and using these results to validate an environmental model of risk to lead exposure.     

Integrating flood hazard into site selection of detention basins using spatial multi-criteria decision-making

This study presents an innovative approach for the integration of flood hazard into the site selection of detention basins. The site selection process is conducted by taking into account multiple criteria and disciplines. Hydraulic modeling results derived from stormwater management model are employed by Technique for the Order of Prioritization by Similarity to Ideal Solution (TOPSIS) to determine flood hazard score. The score generated by TOPSIS is used in a spatial multi-criteria decision-making site selection framework. Applying the framework, a suitability map is generated in which primary locations for detention basin placement are determined. The method is demonstrated through the case study of Darakeh River Catchment, which is located in northern Tehran, Iran. The presented framework can be easily utilized for site selection of other stormwater management techniques, such as low impact development and best management practices, due to its versatility.     

Sex differences in home range and cognitive maps in eight-year old children

This study investigated the hypothesis that there is a sex difference in the extent of children's home ranges and therefore a corresponding difference in their home area cognitive maps. Cognitive maps were elicited using a road construction kit and the resulting maps scored for embedding, extent and detail. Home ranges were investigated using a photographic recognition test and by children indicating home range extent on aerial photographs. The results supported the hypothesis of a sex difference. However, these sex-related mapping differences disappeared when children were required to create maps of areas to which both sexes had limited and controlled exposure. Thus, the original sex-related differences appear to be associated with differences in the size of familiar territory rather than with any male superiority in spatial cognition or map-building ability. The latter was shown to be related to general intelligence as reflected by scores on Raven's Progressive Matrices.     

Component modeling for the spatial representation of wildlife movements

This paper has two main objectives: (1) to discuss the basics of component modeling and its conceptual implications in environmental modeling; and (2) based on this discussion, to present a component-based design to support the simulation of wildlife movements. Components are independently developed, ready-to-use software units that can be assembled together to construct a modeling system. The conceptual implications of component modeling for the representation of environmental phenomena are discussed. A comparison is made between these conceptual implications and those of the more familiar object-oriented approach. A component-based design for supporting the simulation of wildlife movements is presented in this paper in order to illustrate how component modeling can be used to support the spatial representation of ecological phenomena and processes.