Prioritized Spatial Updating in the Intrinsic Frame of Reference

In order to maintain valid situation awareness, people need to update the spatial representations of their surroundings as objects, including themselves, move. The present study investigates the properties of spatial updating in the intrinsic frame of reference, where spatial relations are represented with respect to an external object (other than the viewer self) with an intrinsic reference direction. Three experiments were conducted using a task of direction pointing. It was found that given a relatively stable intrinsic reference direction, responses to a small number of salient objects were faster than responses to non-salient objects (Experiment 1 and Experiment 3). The salience effect disappeared when the intrinsic reference direction was no longer stable (Experiment 2). Furthermore, all three experiments revealed a type of orientation dependence similar to that found in egocentric spatial updating. Our results indicate that spatial updating in the intrinsic reference system can be easy only if a fixed reference direction is maintained and the number of objects that need to be tracked is limited.     

The Effect of an Extra Object on the Linguistic Apprehension of the Spatial Relationship between Two Objects

A sentence describing a spatial relationship includes at least two objects: a located object and a reference object. The presence of an extra object in a scene that is recognized as neither a located nor a reference object, reduces the acceptability of spatial terms related to the spatial relationship between reference and located objects under given conditions (Carlson & Logan, 2001). However, it is still unclear how the overall acceptability distribution of a spatial term changes in a scene when an extra object is present in various locations. In this study, we examined this point, using the paired comparison method with Thurstone's law of judgment (Case V). The results showed that an extra object had both relative increase and reduction effects on the overall acceptability distribution of a spatial term. This suggests that our linguistic apprehension of the spatial relationship is biased intricately by the presence of extra objects.     

Egocentric frames of reference used for the retrieval of survey knowledge learned by map and navigation

Two experiments are reported that use a ``point-to-unseen-targets' task to study the role of egocentric reference frames in the retrieval of survey knowledge learned from either studying a map or navigating an environment. In Experiment 1, performance was generally consistent with the hypothesis that map knowledge is retrieved using a frame of reference centered on the eye, characterized by (a) a fixed orientation in a ``frontal representational plane' and (b) equal access to spatial relations both in front of, or above, and behind, or below, a right-left retrieval axis. The results of Experiment 2 were consistent with the hypothesis that environment knowledge is retrieved within a frame of reference centered on the body, characterized by (a) flexible orientation within a ``transverse representational plane' and (b) privileged access to spatial relations located in front of the right-left retrieval axis in representational space. Both types of knowledge function as if they preserve information about the Euclidean angles connecting elements in physical space.     

Representing a stable environment by egocentric updating and invariant representations

To represent a stable environment despite the experience of changes during self movements, one can either develop an invariant allocentric representation, or update the egocentric representations as one moves. Using a disorientation paradigm, three sets of studies investigated these mechanisms in human navigation and scene recognition. Accuracy in the configuration of multiple object localization is impaired by disorientation, an effect not due to artifacts such as memory deterioration over time, intervening physical activities, uncertainty in self position and orientation, etc., suggesting one can locate objects primarily by updating their egocentric positions as she or he moves. Disorientation also impaired the judgment of changes to a scene after viewer movements, suggesting a similar egocentric updating process. On the contrary, representation of the shape of the surroundings is invariant and persists through disorientation. The coexistence of multiple mechanisms may increase the flexibility and robustness of the system.     

Verb Semantics Affects the Interpretation of Spatial Prepositions

Abstract

Spatial prepositions, more specifically projective prepositions, such as in front of or behind can be interpreted in different ways. Their interpretation depends on the spatial perspective taken as the basis for determining the reference frame's orientation. In 3 series of placement experiments with German speakers, we examined whether the interpretation of projective prepositions in a motion context is affected by the verb used in a spatial instruction. Results suggest that verb semantics is a factor accounting for previously observed seemingly social-situational differences in the interpretation of projective prepositions. Specifically, the findings indicate that, relative to a car as reference object, the semantic aspect of motion interruption associated with some verbs leads to a higher proportion of deictic interpretations determined by the direction from which one is approaching the car. This verb effect on the interpretation of spatial prepositions can be explained by an activation of the temporal dimension through stop-implying verbs, which is integrated into the spatial situation model of the perceived dynamic scene making the deictic frame of reference more compatible. The experimental evidence also shows that verb semantics can account for previously unexplained cross-linguistic differences, and is related to patterns concerning the prepositional inventory of languages.     

Children's control of reference systems in spatial tasks: Foundations of spatial cognitive skill?

Two experiments are presented, one that focused on the abilities of 3- through 8-year-old children to use frames of reference as means for solving a search task in a small-scale perceived space and one that focused on the abilities of 8- through 11-year-old children to use different frames of reference to answer questions about the locations of objects in an environment they had read about. Experiment 1 revealed developmental improvement in the consistent application of object-, place-, and viewer-based frames of reference, with scale of space impacting the pattern of age-related improvement. Experiment 2 showed that young readers' first successes with switching from one reference system to another in representational space involved a vantage point perspective, a viewer-based ``gaze tour' of a small-scale area. Although disparate in focus and method, the studies point to the need for a new theoretical framework for examining developmental issues in the application of spatial frames of reference.     

Editorial: Cognitive Semantics and Spatio-Temporal Ontologies

How do people describe the location of a target object to another? This task requires a reference object or frame and terms of reference. Traditional linguistic analyses have loosely organized perspectives around people, objects, or environments as reference objects, using reference terms based on a viewpoint or the intrinsic sides of an object, such as left, right, front, and back or based on the environment, such as north, south, east, and west. In actual communication, social, spatial, and cognitive factors may also affect perspective choice. We examine those factors by varying the spatial information (landmarks and cardinal directions), the communication task (relative cognitive burden to speakers and addressees), and the culture of participants (American and Japanese). Speakers used addressees' perspectives more when addressees had the greater cognitive burden. They also used landmarks and cardinal directions when they were available, especially to avoid difficult discriminations like left/right. Some cases appearing to be perspective taking can be interpreted as using a person as a landmark. Finally, terms like near indicating close proximity were preferred to far and to terms requiring projection of directions. Globally, perspective choices of American and Japanese samples were strikingly similar; that is, Japanese did not select addressees' perspectives more than Americans. The traditional linguistic analyses need to be enhanced to account for effects of cognitive, situational, and social factors.     

Why do speakers mix perspectives?

Although considerations of discourse coherence and cognitive processing suggest that communicators should adopt consistent perspectives when describing spatial scenes, in many cases they switch perspectives. Ongoing research examining cognitive costs indicates that these are small and exacted in establishing a mental model of a scene but not in retrieving information from a well-known scene. A perspective entails a point of view, a referent object, and terms of reference. These may change within a perspective, exacting cognitive costs, so that the costs of switching perspective may not be greater than the costs of maintaining the same perspective. Another project investigating perspective choice for self and other demonstrates effects of salience of referent object and ease of terms of reference. Perspective is mixed not just in verbal communications but also in pictorial ones, suggesting that at times, switching perspective is more effective than maintaining a consistent one.     

The Influence of Movement,Alignment and Orientation on the Comprehension of Spatial Adpositions in English and Finnish

In contrast to English, Finnish has several postpositions which indicate in front of locations (edella, edessa) and behind locations (takana, jaljessa and perassa). Based on predictions generated from findings from other prepositions in English, and following the prediction by Nikanne (2003) that some postpositions mark motion while others do not, an experiment was designed to examine the influence of movement, alignment, and orientation of located and reference objects on the comprehension of in front of and behind in English and the corresponding Finnish postpositions. Native speakers of English and Finnish had to rate the appropriateness of sentences containing these terms to describe pictures of cars at various positions on a roundabout. The results show similarity between "in front of" and 7quot;behind" terms across languages. While movement does distinguish between "behind" terms in Finnish, in both Finnish and English movement only affected the acceptability of "in front of" and "behind" when reference frame conflicts were present.     

Spatial Memory Organized by Environmental Geometry

We investigated the simultaneous effects of different reference systems on spatial memory. Participants studied a configuration of objects surrounding them. During retrieval, they imagined themselves in the center of the object configuration facing a particular object, and then indicated the directions of other objects relative to this imagined heading. Besides strong effects of egocentric retrieval direction, retrieval was enhanced for objects and headings aligned with an object-centered reference system (triangular object configuration within a neutrally-shaped room), or with a sufficiently salient environmental reference system (triangular room surrounding a neutrally-shaped object configuration). Moreover, remembered object positions were spatially distorted by the object-centered reference system. Results suggest that object positions are accessed by imagining oneself within a topographical representation of objects which is preorganized in terms of both environmental and object-centered reference systems.     

Geometric structures of frames of reference and natural language semantics

This article aims at formal specifications of reference systems in spatial cognition. It concentrates on two roles of reference systems connected to spatial language: reference systems resolving ambiguities and reference systems forming a basis for the classification of linguistic terms. Although coordinate systems are often seen as candidates for the geometric structure of reference systems, it is shown here that they do not appear in the explanations that go into the details. An analysis of the German terms vor, hinter, rechts and links (in front of, in back of, right, left) presents an alternative model for the geometric structure of spatial reference systems.     

Multiple Systems for Spatial Imagery: Transformations of Objects and Bodies

Problem-solving often requires imagining spatial changes. Object-based transformations allow imagining an object in a different orientation. Perspective transformations allow imagining changes in one's viewpoint. Three experiments tested the hypothesis that these two transformations are dissociable and specialized for different situations, by manipulating instructions and task parameters and measuring response times, errors, and introspective reports. Human experience with small objects such as telephones and clothes irons consists mostly of manipulation or observed manipulation, which is characterized by object-based transformations. Consistent with this experience, when participants made judgments about small manipulable objects, they showed a strong tendency to use object-based transformations. Experience with human bodies is more varied, including both object-like interactions and interactions in which one must estimate another's perspective. Accordingly, when making judgments about pictures of bodies, participants' selection of a spatial transformation depended on the type of judgment that needed to be made. When instructions violated these natural mappings, performance was impaired. These data argue for the view that multiple spatial transformation systems evolved to solve different spatial reasoning problems.     

Spatial updating and common misinterpretations of spatial reference frames

Spatial memory plays an important role in everyday life, and a large amount of research has been devoted to understanding spatial coding and reference frames across many areas. The popular research paradigms to study spatial reference frames include novel shortcut, perspective change, and landmark control tests. However, the growing research on spatial updating challenges the logical foundation of these classical paradigms, and suggests that the experimental findings using these paradigms have usually been misinterpreted. That is, performance in these tasks is generally unrelated to whether the spatial representations themselves are egocentric or allocentric. This article reviews the traditional paradigms and their logic, summarizes the theories of spatial updating, analyzes the logical flaws in these popular paradigms, and discusses their implications.     

连续景象匹配的后处理算法

下视景象匹配是各类巡航飞行器实现导航误差修正的关键技术。由于基准图和实时图存在差异，配准点往往落在相关阵的次峰上，导致匹配的失败。提出了N帧连续景象匹配决策的图论算法。该算法利用单帧匹配后形成的相关阵中的主次峰信息以及惯导的位移信息，进行多帧景象匹配的一致性决策。由于引入了相关阵中的次峰信息并结合惯导位移的一致性判断，使得匹配算法能有效剔除误匹配点，从而提高算法的鲁棒性和匹配概率。     

The face inversion effect in microgravity: is gravity used as a spatial reference for complex object recognition?

Complex objects are better recognized under a specific orientation. When presented upside down, a face, even very familiar, is recognized with greater difficulty than when presented upright ("Inversion effect"). Up to now it was not possible to decide whether the direction provided by gravity or the one provided by the retina and the body constitutes the spatial reference involved in this "Inversion effect". Three cosmonautes learned photographed faces on the ground and had to recognize them both on ground and on flight. Other photographed faces were learned in flight and where presented for recognition on flight. Results show that the Inversion effect is still present on flight for faces that have been learned on ground as well as for those learned on flight. Persistence of the inversion effect in 0-G shows that gravity is not involved as a spatial reference in recognition of faces. Learning and recognition performances of faces learned in flight were significantly lower than performances for faces learned on ground. A possible role of gravity in configural processing, but not in the Inversion effect, is suggested.     

Context Affects Scale Selection for Proximity Terms

Abstract

Spatial proximity terms, such as near and far, communicate information regarding the distance in which a “located” object can be found with respect to a “reference” object. The present paper investigates whether people take into account the location of an object extraneous to the located object and reference object pair, when setting the scale for proximity language judgements. Across three experiments participants rated the appropriateness of near and far to describe spatial scenes that included a third (distractor) object positioned the same distance as the located object from the reference object, but at varying distances from the located object. The results show that the presence of other spatial relations affects scale setting, resulting in differences in appropriateness ratings for those spatial terms.