Reorientation and landmark-guided search by young children: evidence for two systems

Disoriented 4-year-old children use a distinctive container to locate a hidden object, but do they reorient by this information? We addressed this question by testing children's search for objects in a circular room containing one distinctive and two identical containers. Children's search patterns provided evidence that the distinctive container served as a direct cue to a hidden object's location, but not as a directional signal guiding reorientation. The findings suggest that disoriented children's search behavior depends on two distinct processes: a modular reorientation process attuned to the geometry of the surface layout and an associative process linking landmarks to specific locations.     

Children's use of geometry for reorientation

Research on navigation has shown that humans and laboratory animals recover their sense of orientation primarily by detecting geometric properties of large-scale surface layouts (e.g. room shape), but the reasons for the primacy of layout geometry have not been clarified. In four experiments, we tested whether 4-year-old children reorient by the geometry of extended wall-like surfaces because such surfaces are large and perceived as stable, because they serve as barriers to vision or to locomotion, or because they form a single, connected geometric figure. Disoriented children successfully reoriented by the shape of an arena formed by surfaces that were short enough to see and step over. In contrast, children failed to reorient by the shape of an arena defined by large and stable columns or by connected lines on the floor. We conclude that preschool children's reorientation is not guided by the functional relevance of the immediate environmental properties, but rather by a specific sensitivity to the geometric properties of the extended three-dimensional surface layout.     

Experience and geometry: controlled-rearing studies with chicks

Animals can reorient making use of the geometric shape of an environment, i.e., using sense and metric properties of surfaces. Animals reared soon after birth either in circular or in rectangular enclosures (and thus affording different experiences with metric properties of the spatial layout) showed similar abilities when tested for spatial reorientation in a rectangular enclosure. Thus, early experience in environments with different geometric characteristics does not seem to affect animals’ ability to reorient using sense and metric information. However, some results seem to suggest that when geometric and non-geometric information are set in conflict, rearing experience could affect the relative dominance of featural (landmark) and geometric information. In three separate experiments, newborn chicks reared either in circular- or in rectangular-shaped home-cages were tested for spatial reorientation in a rectangular enclosure, with featural information provided either by panels at the corners or by a blue-coloured wall. At test, when faced with affine transformations in the arrangement of featural information that contrasted with the geometric information, chicks showed no evidence of any effect of early experience on their relative use of geometric and featural information for spatial reorientation. These findings suggest that, at least for this highly precocial species, the ability to deal with geometry seems to depend more on predisposed mechanisms than on learning and experience after hatching.     

Navigation as a source of geometric knowledge: young children's use of length, angle, distance, and direction in a reorientation task

Geometry is one of the highest achievements of our species, but its foundations are obscure. Consistent with longstanding suggestions that geometrical knowledge is rooted in processes guiding navigation, the present study examines potential sources of geometrical knowledge in the navigation processes by which young children establish their sense of orientation. Past research reveals that children reorient both by the shape of the surface layout and the shapes of distinctive landmarks, but it fails to clarify what shape properties children use. The present study explores 2-year-old children's sensitivity to angle, length, distance and direction by testing disoriented children's search in a variety of fragmented rhombic and rectangular environments. Children reoriented themselves in accord with surface distances and directions, but they failed to use surface lengths or corner angles either for directional reorientation or as local landmarks. Thus, navigating children navigate by some but not all of the abstract properties captured by formal Euclidean geometry. While navigation systems may contribute to children's developing geometric understanding, they likely are not the sole source of abstract geometric intuitions.     

A modular geometric mechanism for reorientation in children

Although disoriented young children reorient themselves in relation to the shape of the surrounding surface layout, cognitive accounts of this ability vary. The present paper tests three theories of reorientation: a snapshot theory based on visual image-matching computations, an adaptive combination theory proposing that diverse environmental cues to orientation are weighted according to their experienced reliability, and a modular theory centering on encapsulated computations of the shape of the extended surface layout. Seven experiments test these theories by manipulating four properties of objects placed within a cylindrical space: their size, motion, dimensionality, and distance from the space’s borders. Their findings support the modular theory and suggest that disoriented search behavior centers on two processes: a reorientation process based on the geometry of the 3D surface layout, and a beacon-guidance process based on the local features of objects and surface markings.     

路标信息在幼儿空间再定向中的作用

以往研究表明幼儿不能有效地整合利用路标等非几何信息,主要依赖几何信息进行再定向。即使能利用路标信息,也只是建立了靶物体与路标之间的直接联结,而不是用于空间再定向。本研究在矩形房间的四角设置颜色不同的档板作为路标线索,以平均年龄为3.5岁的幼儿为被试,结果发现,在几何信息与路标信息同时存在的情形下,幼儿可以整合利用空间中的几何信息与路标信息;即使只有路标信息,幼儿也能依赖路标信息结合左右方位感准确地再定向,这些结果表明幼儿能够充分利用空间中的路标信息以重新确定自己的方位。     

Young children's use of features to reorient is more than just associative: further evidence against a modular view of spatial processing

Proponents of a geometric module have argued that instances of young children's use of features as well as geometry to reorient can be explained by a two-stage process. In this model, only the first stage is a true reorientation, accomplished by using geometric information alone; features are considered in a second stage using association ( Lee, Shusterman & Spelke, 2006 ). This account is contradicted by the data from two experiments. Experiment 1a sets the stage for Experiment 1b by showing that young children use geometric information to reorient in a complex geometric figure without a single principal axis of symmetry (an octagon). In such a figure, there are two sets of geometrically congruent corners, with four corners in each set. The addition of a colored wall leads to the existence of three geometrically congruent but, crucially, all unmarked corners; using the colored wall to distinguish among them could not be done associatively. In Experiment 1b, both 3- and 5-year-old children showed true non-associative reorientation using features by performing at above-chance levels on all-white trials. Experiment 2 used a paradigm without distinctive geometry, modeled on Lee et al. (2006) , involving an equilateral triangle of hiding places located within a circular enclosure, but with a large stable feature rather than a small moveable one. Four-year-olds (the age group studied by Lee et al.) used features at above-chance levels. Thus, features can be used to reorient, in a way not dependent on association, in contradiction to the two-stage version of the modular view.     

Children's use of geometry and landmarks to reorient in an open space

Eight experiments tested the abilities of 3-4-year-old children to reorient themselves and locate a hidden object in an open circular space furnished with three or four landmark objects. Reorientation was tested by hiding a target object inside one of the landmarks, disorienting the child, observing the child's search for the target, and comparing the child's performance to otherwise similar trials in which the child remained oriented. On oriented trials, children located the target successfully in every experiment. On disoriented trials, in contrast, children failed to locate the object when the landmarks were indistinguishable from one another but formed a distinctive geometric configuration (a triangle with sides of unequal length or a rectangle). This finding provides evidence that the children failed to use the geometric configuration of objects to reorient themselves. As in past research, children also did not appear to reorient themselves in accord with non-geometric properties of the layout. In contrast to these findings, children successfully located the object in relation to a geometric configuration of walls. Moreover, adults, who were tested in two further experiments, located the object by using both geometric and non-geometric information. Together, these ten experiments provide evidence that early-developing navigational abilities depend on a mechanism that is sensitive to the shape of the permanent, extended surface layout, but that is not sensitive to geometric or non-geometric properties of objects in the layout.     

Is language necessary for human spatial reorientation? Reconsidering evidence from dual task paradigms

Being able to reorient to the spatial environment after disorientation is a basic adaptive challenge. There is clear evidence that reorientation uses geometric information about the shape of the surrounding space. However, there has been controversy concerning whether use of geometry is a modular function, and whether use of features is dependent on human language. A key argument for the role of language comes from shadowing findings where adults engaged in a linguistic task during reorientation ignored a colored wall feature and only used geometric information to reorient [Hermer-Vazquez, L., Spelke, E., & Katsnelson, A. (1999). Sources of flexibility in human cognition: Dual task studies of space and language. Cognitive Psychology, 39, 3-36]. We report three studies showing: (a) that the results of Hermer-Vazques et al. [Hermer-Vazquez, L., Spelke, E., & Katsnelson, A. (1999). Sources of flexibility in human cognition: Dual task studies of space and language. Cognitive Psychology, 39, 3-36] are obtained in incidental learning but not with explicit instructions, (b) that a spatial task impedes use of features at least as much as a verbal shadowing task, and (c) that neither secondary task impedes use of features in a room larger than that used by Hermer-Vazquez et al. These results suggest that language is not necessary for successful use of features in reorientation. In fact, whether or not there is an encapsulated geometric module is currently unsettled. The current findings support an alternative to modularity; the adaptive combination view hypothesizes that geometric and featural information are utilized in varying degrees, dependent upon the certainty and variance with which the two kinds of information are encoded, along with their salience and perceived usefulness.     

Use of geometry for spatial reorientation in children applies only to symmetric spaces

Proponents of the geometric module hypothesis argue that following disorientation, many species reorient by use of macro‐environment geometry. It is suggested that attention to the surface layout geometry of natural terrain features may have been selected for over evolutionary time due to the enduring and unambiguous location information it provides. Paradoxically, however, tests of the hypothesis have been exclusively conducted in symmetric (hence ‘unnatural’ and geometrically ambiguous) environments. The present series of studies examines reorientation by 18‐month–3‐year‐old children in a rectangular versus irregular quadrilateral enclosure (Study 1), a rectangular versus irregular quadrilateral array (Study 2) and an isosceles versus irregular triangular array (Study 3). Children were successful in symmetric but not asymmetric environments, casting doubt on the functional argument for an empirical basis of the geometric module hypothesis.     

Core Knowledge and the Emergence of Symbols: The Case of Maps

Map reading is unique to humans but is present in people of diverse cultures, at ages as young as 4 years old. Here, we explore the nature and sources of this ability and ask both what geometric information young children use in maps and what nonsymbolic systems are associated with their map-reading performance. Four-year-old children were given two tests of map-based navigation (placing an object within a small three-dimensional [3D] surface layout at a position indicated on a two-dimensional [2D] map), one focused on distance relations and the other on angle relations. Children also were given two nonsymbolic tasks, testing their use of geometry for navigation (a reorientation task) and for visual form analysis (a deviant-detection task). Although children successfully performed both map tasks, their performance on the two map tasks was uncorrelated, providing evidence for distinct abilities to represent distance and angle on 2D maps of 3D surface layouts. In contrast, performance on each map task was associated with performance on one of the two nonsymbolic tasks: Map-based navigation by distance correlated with sensitivity to the shape of the environment in the reorientation task, whereas map-based navigation by angle correlated with sensitivity to the shapes of 2D forms and patterns in the deviant-detection task. These findings suggest links between one uniquely human, emerging symbolic ability, geometric map use, and two core systems of geometry.     

儿童空间再定向的几何模块论及其局限

儿童的空间再定向指的是迷失方向的儿童在空间中重新确定自己方位并找回被藏物体的能力。儿童的这一能力与某些低等哺乳动物（如大鼠）相似,都只能利用空间环境所构成的几何信息,不能利用非几何信息来再定向。几何模块论认为造成这一现象的原因是儿童与低等哺乳动物的认知系统里存在几何模块。然而,众多研究对这种简单化的观点提出了异议。针对这些异议,几何模块论又进行了新的修订     

Modularity and spatial reorientation in a simple mind: encoding of geometric and nongeometric properties of a spatial environment by fish

When disoriented in environments with distinctive geometry, such as a closed rectangular arena, human infants and adult rats reorient in accord with the large-scale shape of the environment, but not in accord with nongeometric properties such as the colour of a wall. Human adults, however, conjoined geometric and nongeometric information to reorient themselves, which has led to the suggestion that spatial processing tends to become more flexible over development and evolution. We here show that fish tested in the same tasks perform like human adults and surpass rats and human infants. These findings suggest that the ability to make use of geometry for spatial reorientation is an ancient evolutionary tract and that flexibility and accessibility to multiple sources of information to reorient in space is more a matter of ecological adaptations than phylogenetic distance from humans.     

儿童空间再定向能力发展的理论之争

空间再定向是指迷失方向的个体在空间中重新确定自己方位并找回迷失方向前丢失或被隐藏物体的能力.几何模块理论、适应性结合理论和视觉图像匹配理论都能够对儿童空间再定向做出一定解释,但三者之间互不相容,并存在局限:解释不了语言对整合几何和非几何信息的影响、环境空间大小和参照系选择对再定向的影响以及空间再定向中性别差异的现象.今后研究应注意实验的生态效应、空间条件的规则性、几何信息的直接性与间接性以及对三个理论的整合.     

Children's use of landmarks: implications for modularity theory

Previous studies have shown that disoriented children use the geometric features of the environment to reorient, but the results have not consistently demonstrated whether children can combine such information with landmark information. Results indicating that they cannot suggest the existence of a geometric module for reorientation. However, results indicating that children can use geometric information in combination with landmark information challenge the modularity interpretation. An uncontrolled variable in the studies yielding conflicting results has been the size of the experimental space. In the present studies, which tested young children in spaces of two different sizes, the size of the space affected their ability to use available landmark information. In the small space, the children did not use the landmark to reorient, but in the large space they did. The ability of children to use landmarks in combination with geometric information raises important questions about the existence of an encapsulated geometric module.     

Representation of two geometric features of the environment in the domestic chick (<Emphasis Type="Italic">Gallus gallus</Emphasis>)

We report experiments based on a novel test in domestic chicks (Gallus gallus), designed to examine the encoding of two different geometric features of an enclosed environment: relative lengths of the walls and amplitude of the corners. Chicks were trained to search for a food reward located in one corner of a parallelogram-shaped enclosure. Between trials, chicks were passively disoriented and the enclosure was rotated, making reorientation possible only on the basis of the internal spatial structure of the enclosure. In order to reorient, chicks could rely on two sources of information: the relative lengths of the walls of the enclosure (associated to their left-right sense order) and the angles subtended by walls at corners. Chicks learned the task choosing equally often the reinforced corner and its rotational equivalent. Results of tests carried out in novel enclosures, the shapes of which were chosen ad hoc (1) to induce reorientation based only on the ratio of walls lengths plus sense (rectangular enclosure), or (2) to induce reorientation based only on corner angles (rhombus-shaped enclosure), suggested that chicks encoded both features of the environment. In a third test, in which chicks faced a conflict between these geometric features (mirror parallelogram-shaped enclosure), reorientation seemed to depend on the salience of corner angles. These results shed light on the elements of the environmental geometry which control spatial reorientation, and broaden the knowledge on the geometric representation of space in animals.     

Inexperienced newborn chicks use geometry to spontaneously reorient to an artificial social partner

A fundamental process underlying navigation behaviour, shown to occur in every species tested, uses geometric properties of the environment for location memory and orientation. Here we employ a new method to ask whether this basic geometric orientation ability is innately predisposed in the brain or depends on specific experiences navigating in a geometrically rich environment. Using the newborn domestic chick as a model system, we present a working memory task testing reorientation towards a filial imprinting object under rigorous controlled rearing conditions. In the absence of any previous exposure to a geometrically rich environment, newly hatched chicks spontaneously recovered their bearings by making use of distances and directional relations to reorient themselves to an artificial social partner. These findings provide evidence for an innate capacity to navigate by the geometric structure of the environment.     

Using perceptrons to explore the reorientation task

The reorientation task is a paradigm that has been used extensively to study the types of information used by humans and animals to navigate in their environment. In this task, subjects are reinforced for going to a particular location in an arena that is typically rectangular in shape. The subject then has to find that location again after being disoriented, and possibly after changes have been made to the arena. This task is used to determine the geometric and featural cues that can be used to reorient the agent in the arena. The purpose of the present paper is to present several simulation results that show that a simple neural network, a perceptron, can be used to generate many of the traditional findings that have been obtained using the reorientation task. These results suggest that reorientation task regularities can be explained without appealing to a geometric module that is a component of spatial processing.     

Reorientation in the real world: the development of landmark use and integration in a natural environment

An influential series of studies have argued that young children are unable to use landmark information to reorient. However, these studies have used artificial experimental environments that may lead to an underestimation of the children’s ability. We tested whether young children could reorient using landmarks in an ecologically valid setting. Children aged between 3 and 7 years completed a reorientation task in open parkland, and the properties of the search array (size and distinctiveness) were manipulated in a within-subjects design. Responses were recorded using Global Positioning Systems technology. All age groups performed above chance level, demonstrating that young children can reorient using natural landmarks. This behaviour was modulated by the nature of the search array: children were more accurate when the locations were spaced in a large array, and when the search locations were distinctively coloured. This suggests that the integration between landmarks and search locations, at different spatial scales, is a key factor in characterising human reorientation in the real world.     

Dissecting the geometric module: a sense linkage for metric and landmark information in animals' spatial reorientation

Disoriented children can use geometric information in combination with featural information to reorient themselves in large but not in small spaces; somewhat similar effects have been found in nonhuman animals. These results call for an explanation. We trained young chicks to reorient to find food in a corner of a small or a large rectangular room with a distinctive featural cue (a blue wall) -- a task similar to that used with children. Then we tested the chicks after displacement of the feature to an adjacent wall. In the large enclosure, chicks chose the corner that maintained the correct arrangement of the featural cue with respect to sense, whereas in the small enclosure, they chose the corner that maintained the correct metrical arrangement of the walls with respect to sense. On the basis of these findings, we propose a simple model that can explain the effects of room size on spatial reorientation.