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.     

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.     

Environment size and the use of feature and geometric cues for reorientation

We tested associative-based accounts of orientation by investigating the influence of environment size on the use of feature and geometric cues for reorientation. Two groups of participants were trained in dynamic three-dimensional virtual rectangular environments that differed in size to find a distinctly colored bin located at one of the four corners. Subsequently, we probed the reliance on feature and geometric cues for reorientation during test trials by presenting six trial types: Small Geometry Only, Large Geometry Only, Small Cue Conflict, Large Cue Conflict, Small Distal, and Large Distal. During Geometry Only test trials, all bins were black; thus, all distinctive featural information was removed leaving only geometric cues. For Cue Conflict test trials, all colored bins were shifted counter-clockwise one corner; thus, the geometric cues from the trained corner and the trained color were in direct conflict. During Distal test trials, the bin in the geometrically incorrect corner farthest from the trained corner was colored the same as during training; the remaining three bins were black. Thus, only this distant feature cue could be used to determine the location of the goal bin. Results suggested that geometric cues were used across changes in environment size, featural cues exerted greater influence when in conflict with geometric cues, and the far featural cue was used to disambiguate the correct from the rotationally equivalent location. In short, both feature and geometric cues were used for reorientation, and environment size influenced the relative use of feature and geometric cues. Collectively, our results provide evidence against associative-based accounts of orientation.     

Children's use ofGet passives

Children's use ofget in passivelike constructions was examined in this study. Fifty-eight children at three age levels were tested twice on imitation, comprehension, and production tasks. For the imitation and comprehension tasks, passive sentences withget were modeled in one instance and withbe in the other instance. On both tasks, children performed significantly better on theget items than on thebe items. For the production tasks, active sentences were used as the experimental stimuli. Among 928 production responses possible, children produced 423get passives and 6be passives. The frequency ofget passives increased with increasing age. Qualitative analyses were performed to determine agerelated changes in the pattern of linguistic strategies chosen. These data were consistent with predictions derived from a model of lexical directionality: Children used moreget thanbe passives and more truncated than full passives.     

Enclosure size and the use of local and global geometric cues for reorientation

Multiple spatial cues are utilized to orient with respect to the environment, but it remains unclear why feature (i.e., objects in the environment) and geometric (i.e., shape of the environment) cues are differentially influenced by enclosure size, and the extent to which local (i.e., wall lengths and corner angles) and global (i.e., principal axis of space) geometric cues are influenced by enclosure size. In the present study, we investigated the extent to which environmental size influenced the use of corner angle (i.e., a local geometric cue) and the principal axis of space (i.e., a global geometric cue) for reorientation. We developed an orientation task that allowed the manipulation of enclosure size during training and the isolation of the use of the principal axis of space during testing. Participants were trained to respond to a location in either a small or a large trapezoid-shaped enclosure uniquely specified by both local (i.e., wall lengths and corner angles) and global (i.e., principal axis of space) geometric cues. During testing, we presented both groups with a small and large rectangle (to assess the use of principal axis of space) and a small and large parallelogram (to asses relative use of corner angles and the principal axis of space when in conflict). Enclosure size influenced the relative use of corner angles but not of the principal axis of space. Results suggest that corner angles function like features and that changes in the use of feature cues are the source of the relative reliance on feature and geometric cues during changes of enclosure size.     

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.     

Spatial reorientation: the effects of space size on the encoding of landmark and geometry information

The effects of the size of the environment on animals’ spatial reorientation was investigated. Domestic chicks were trained to find food in a corner of either a small or a large rectangular enclosure. A distinctive panel was located at each of the four corners of the enclosures. After removal of the panels, chicks tested in the small enclosure showed better retention of geometrical information than chicks tested in the large enclosure. In contrast, after changing the enclosure from a rectangular-shaped to a square-shaped one, chicks tested in the large enclosure showed better retention of landmark (panels) information than chicks tested in the small enclosure. No differences in the encoding of the overall arrangement of landmarks were apparent when chicks were tested for generalisation in an enclosure differing from that of training in size together with a transformation (affine transformation) that altered the geometric relations between the target and the shape of the environment. These findings suggest that primacy of geometric or landmark information in reorientation tasks depends on the size of the experimental space, likely reflecting a preferential use of the most reliable source of information available during visual exploration of the environment.     

Rhesus monkeys use geometric and nongeometric information during a reorientation task

Rhesus monkeys (Macaca mulata) were subjected to a place finding task in a rectangular room perfectly homogeneous and without distinctive featural information. Results of Experiment 1 show that monkeys rely on the large-scale geometry of the room to retrieve a food reward. Experiments 2 and 3 indicate that subjects use also nongeometric information (colored wall) to reorient. Data of Experiments 4 and 5 suggest that monkeys do not use small angular cues but that they are sensitive to the size of the cues (Experiments 6, 7, and 8). Our findings strengthen the idea that a mechanism based on the geometry of the environment is at work in several mammalian species. In addition, the present data offer new perspectives on spatial cognition in animals that are phylogenetically close to humans. Specifically, the joint use of both geometric and landmark-based cues by rhesus monkeys tends to demonstrate that spatial processing became more flexible with evolution.     

Children's use of the temporal dimension of gaze for inferring preference

This study examined 4- and 5-year-olds' ability to spontaneously use the relative duration and frequency of another's object-directed gaze for inferring that person's preference. In Experiment 1, analysis revealed a strong age effect for judgment accuracy, which could not be accounted for by cue-monitoring proficiency. Reducing the saliency of the objects in Experiment 2 yielded significant improvement in the younger children's performance. Thus, at 4 years, children already show signs of attending to the temporal dimension of gaze for making mentalistic inferences of preferential liking, but their competence may be undermined by the object choices themselves. By 5 years, they appear to overcome this competition. The obtained developmental difference is discussed in terms of concurrent transitions in attention regulation.     

Children's use of frequency information for trait categorization and behavioral prediction

Two experiments examined young children's use of behavioral frequency information to make behavioral predictions and global personality attributions. In Experiment 1, participants heard about an actor who behaved positively or negatively toward 1 or several recipients. Generally, children did not differentiate their judgments of the actor on the basis of the amount of information provided. In Experiment 2, the actor behaved positively or negatively toward a single recipient once or repeatedly. Participants were more likely to make appropriate predictions and attributions after exposure to multiple target behaviors and with increasing age. Overall, children's performance was influenced by age-related positivity and negativity biases. These findings indicate that frequency information is important for personality judgments but that its use is affected by contextual complexity and information-processing biases.     

A viewpoint-independent process for spatial reorientation

Reorientation tasks, in which disoriented participants attempt to relocate objects using different visual cues, have previously been understood to depend on representing aspects of the global organisation of the space, for example its major axis for judgements based on geometry. Careful analysis of the visual information available for these tasks shows that successful performance could be based on the much simpler process of storing a visual ‘snapshot’ at the target location, and subsequently moving in order to match it. We tested 4-8-year olds on a new spatial reorientation task that could not be solved based on information directly contained in any retinal projection that they had been exposed to, but required participants to infer how the space is structured. Only 6-8-year olds showed flexible recall from novel viewpoints. Five-year olds were able to recall locations given movement information or a unique proximal landmark, but without these they could not do so, even when they were not disoriented or when the landmark was a familiar object. These results indicate that early developing spatial abilities based on view matching and self motion are supplemented by a later-developing process that takes into account the structure of spatial layouts and so enables flexible recall from arbitrary viewpoints.     

Independent effects of geometry and landmark in a spontaneous reorientation task: a study of two species of fish

While disoriented humans and animals use both landmarks and environmental geometry to guide their navigation, it is not clear what kinds of cognitive mechanisms underlie these behaviors. Because traditional tests of trained navigation behavior in environments containing both landmarks and geometric information may cloud our insight into the nature of these processes, the present study tested the spontaneous use of landmarks and environmental shape by two species of fish-Redtail Splitfins (Xenotoca eiseni) and Zebrafish (Danio rerio). The results suggest that while geometry is spontaneously used by both species and both sexes to compute relative position or direction, the spontaneous use of landmarks is limited to direct beaconing and complicated by attraction to features and variability across species and sex. These findings support the view that while multiple cues may ultimately guide behavior, the computation of orientation and relative positions is specified by geometric input and is independent from other navigation processes such as beaconing.     

Children's strategy use in computational estimation.

This study reports an investigation of ten-year-old children's strategy use in computational estimation (i.e., give an approximate answer like 400 to an arithmetic problem like 224 + 213). Children used four strategies: rounding with decomposition, rounding without decomposition, truncation, and compensation. Strategies appeared to differ in frequency and effectiveness. Finally, children chose strategies in an adaptive way so as to obtain fast and accurate performance. Implications of these findings for understanding children's computational estimation performance and strategies in numerical cognition in general are discussed.     

Children's use of geometric information in mapping tasks

Accumulating evidence, particularly from research using the disorientation technique, demonstrates early sensitivity to geometric properties of space. However, it is not known whether children can use geometric cues to interpret a map. The current study examined how 3- to 6-year-olds use geometric features of layouts in solving mapping tasks. Children were asked to identify a target location in a layout shaped as an isosceles triangle by using information provided in a picture of that layout. Performance depended on whether the shape was presented explicitly or needed to be inferred. Younger participants performed better when the triangle was formed by continuous connected lines than when it was formed by separate objects. Performance also depended on the type of geometric cues available. Children found it easier to establish mapping for targets located in the unique corner of the triangle than for targets located in equal-sized corners. Overall, the findings reveal both a remarkable early ability to use geometric information in mapping and limits in this ability.     

Children's use of verbal collaterals in DRL performance

This study examines the effects of a verbal collateral (counting) on a series of three differential reinforcement of low rates of response (DRL) tasks with progressively longer interresponse time requirements (DRL-2, DRL-6 and DRL-12). Forty-eight 10-year-old children, divided according to sex and conceptual tempo (fast-inaccurate vs. slow-accurate) participated in DRL training, half of them being instructed to count aloud between responses. Counting was found to be related to faster learning of all the tasks and to greater efficiency in obtaining reinforcement in most cases. It also eliminated differences due to sex and conceptual tempo except in DRL-12. However, it had the disadvantage of causing inexact temporal discrimination. The results were replicated in a group of 8-year-old subjects performing the same tasks.     

Children's use of gesture to resolve lexical ambiguity

We report on a study investigating 3–5‐year‐old children's use of gesture to resolve lexical ambiguity. Children were told three short stories that contained two homonym senses; for example, bat (flying mammal) and bat (sports equipment). They were then asked to re‐tell these stories to a second experimenter. The data were coded for the means that children used during attempts at disambiguation: speech, gesture, or a combination of the two. The results indicated that the 3‐year‐old children rarely disambiguated the two senses, mainly using deictic pointing gestures during attempts at disambiguation. In contrast, the 4‐year‐old children attempted to disambiguate the two senses more often, using a larger proportion of iconic gestures than the other children. The 5‐year‐old children used less iconic gestures than the 4‐year‐olds, but unlike the 3‐year‐olds, were able to disambiguate the senses through the verbal channel. The results highlight the value of gesture to the development of children's language and communication skills.     

Young children's spontaneous use of geometry in maps

Two experiments tested whether 4-year-old children extract and use geometric information in simple maps without task instruction or feedback. Children saw maps depicting an arrangement of three containers and were asked to place an object into a container designated on the map. In Experiment 1, one of the three locations on the map and the array was distinct and therefore served as a landmark; in Experiment 2, only angle, distance and sense information specified the target container. Children in both experiments used information for distance and angle, but not sense, showing signature error patterns found in adults. Children thus show early, spontaneously developing abilities to detect geometric correspondences between three-dimensional layouts and two-dimensional maps, and they use these correspondences to guide navigation. These findings begin to chart the nature and limits of the use of core geometry in a uniquely human, symbolic task.     

Children's use of language context in lexical ambiguity resolution

Lexical ambiguity resolution was examined in children aged 7 to 10 years and adults. In Experiment 1, participants heard sentences supporting one (or neither) meaning of a balanced ambiguous word in a cross-modal naming paradigm. Naming latencies for context-congruent versus context-incongruent targets and judgements of the relatedness of targets to the sentence served as indices of appropriate context use. While younger children were faster to respond to related targets regardless of the sentence context, older children and adults showed priming only for context-appropriate targets. In Experiment 2, only a single-word context preceded the homophone, and in contrast to Experiment 1, all groups showed contextual sensitivity. Individual working-memory span and inhibition ability were also measured in Experiment 2, and more mature executive function abilities were associated with greater contextual sensitivity. These findings support a developmental model whereby sentential context use for lexical ambiguity resolution increases with age, cognitive processing capacity, and reading skill.     

Children's use of the bearing angle in interceptive actions

The authors investigated the effect of ball velocity and walking direction on children's adherence to the constant bearing angle (CBA) strategy. Children (N = 20) approached a moving ball to manually intercept it at a predefined target area. Results revealed that 10- to 12-year-olds adhered more than 5- to 7-year-olds to the CBA strategy. Younger children deviated more than older children from smaller angles of approach and lower ball velocities. The present findings suggest that younger children have difficulty adjusting to task requirements because they fail to couple walking velocity with ball velocity. The improvement seen with increasing age suggests that compliance with the CBA strategy may be attributed to older children's enhanced coincidence anticipation.