Route generation and description using the notions of object's influence area and spatial conceptual map

In the GRAAD Project we aimed at creatinga system which could generate route directions thatare comparable to route directions created by humanparticipants. With this goal in mind, we started froma linguistic and cognitive study of route directionsproduced by people and the study of cognitive modelsof mental maps. We proposed a new qualitative spatialmodel that can support the spatial properties of humanroute directions. This model is based on the notion ofobject's influence area which is used to modelneighborhood, orientation and distance. The proposedapproach relies on the manipulation of spatialentities in a spatial conceptual map (SCM) which isthe computarized analog of a mental map used bypeople. We developped the GRAAD System, software thatgenerates routes in a SCM and describes them innatural language. Finally, we conducted an experimentin order to compare GRAAD's route directions androutes described by human participants in similarexperimental conditions. GRAAD's output was notdistinguishable from route directions created by humanparticipants. In this paper we present the mainresults obtained during all phases of the GRAADProject.     

Variable Granularity in Route Directions

Abstract

This paper addresses changes of spatial granularity in route directions in relation to information needs in multimodal traveling. We outline a model of variability in granularity and apply this model to empirical data. Results reveal that linguistic route directions produced by humans as well as automatically generated web-based services provide the most crucial route elements in hierarchically structured ways that reflect the salient structure imposed by multimodal traveling. However, although the web-based information is impressively comprehensive, human route directions exhibit more flexibility regarding switches of place-related granularity, and they provide more detailed information at complex locations or decision points.     

When gestures show us the way: Co-thought gestures selectively facilitate navigation and spatial memory

How does gesturing during route learning relate to subsequent spatial performance? We examined the relationship between gestures produced spontaneously while studying route directions and spatial representations of the navigated environment. Participants studied route directions, then navigated those routes from memory in a virtual environment, and finally had their memory of the environment assessed. We found that, for navigators with low spatial perspective-taking performance on the Spatial Orientation Test, more gesturing from a survey perspective predicted more accurate memory following navigation. Thus, co-thought gestures accompanying route learning relate to performance selectively, depending on the gesturers’ spatial ability and the perspective of their gestures. Survey gestures may help some individuals visualize an overall route that they can retain in memory.     

Spatial Reorientation: Effects of Verbal and Spatial Shadowing

ABSTRACT

Spatially disoriented adults flexibly conjoin geometric information (macroscopic shape) and nongeometric information (e.g., the color of a wall) to re-establish their bearings. It has been proposed that non-geometric information is incorporated into a geometric frame of reference through the use of spatial language. Support for this assumption comes from dual-task studies in which participants failed to use non-geometric features when they shadowed a verbal message concurrent to the reorientation task. These studies were performed in small rectangular spaces. In contrast, our study was performed in a large square room. Experiment 1 showed that verbal shadowing did not disrupt non-geometric feature use in this environment. In Experiment 2, we found that a spatial shadowing task that required the encoding of frequently changing spatial directions impaired reorientation behavior. Our study shows that nongeometric information can be used for reorientation without recourse to linguistic processes, and suggests that the use of non-geometric features is dependent upon a spatial coding process.     

Selection of Salient Features for Route Directions

People navigating in unfamiliar environments rely on wayfinding directions, either given by people familiar with the place, or given by maps or wayfinding services. The essential role of landmarks in human route communication is well-known. However, mapping the human ability to select landmarks ad hoc for route directions to a computational model was never tried before. Wayfinding services manage the problem by using predefined points of interest. These points are not automatically identified, and they are not related to any route. In contrast, here a computational model is presented that selects salient features along a route where needed, e.g., at decision points. We propose measures to formally specify the salience of a feature. The observed values of these measures are subject to stochastical tests in order to identify the most salient features from datasets. The proposed model is implemented and checked for computability with a use case from the city of Vienna. It is also crosschecked with a human subject survey for landmarks along a given route. The survey provides evidence that the proposed model selects features that are strongly correlated to human concepts of landmarks. Hence, integrating the selected salient features in wayfinding directions will produce directions with lower cognitive workload and higher success rates, compared to directions based only on geometry, or on geometry and static points of interest.     

A semantic ‘engine’ for universal translation

Having dedicated prior research to identifying a range of methods for detecting the hierarchical layers of language, which also incorporates unsupervised learning toolkits and a Corpus that represents the entire ‘Human Chorus’, this paper outlines the concepts behind providing the last piece in the jigsaw. This particular piece, which ultimately will provide the ability to decipher meaning without an exhaustive crib or primer, poses the perplexing problem of dealing with the seemingly arbitrary nature of this linguistic ‘veneer’. Techniques that, if perfected, will also have a profound impact on developing a universal translator for everyday translation issues and cryptopalaeography.     

Selecting a reference frame

Reference frames are representations that parse space. In the case of spatial terms, reference frames mediate the mapping of linguistic expressions onto spatial configurations of objects. In the sentence ``The fly is above the cat,' ``above' is defined with respect to a reference frame that is imposed on the cat. Different types of reference frames can be used to define spatial terms, each based on a different source of information. For example, gravity, the orientation of objects in the scene or the orientation of the viewer can all be used to set the orientation of a reference frame. When these reference frames disagree (because the viewer is reclining or because the objects in the scene are overturned), there are competing definitions for the spatial term, resulting in the need for reference frame selection. The purpose of this paper is to review a line of research that examines reference frame selection in the context of spatial language. This work shows that all reference frames are initially active and assign a direction to a spatial term. Moreover, this activation is automatic, and is followed by the selection of a single reference frame, with selection accompanied by inhibition of the non-selected frames. Parallels between reference frame selection in language and in perception and attention are discussed.     

Spatial Reference in Linguistic Human-Robot Interaction: Iterative,Empirically Supported Development of a Model of Projective Relations

The aim of our research is to enable spontaneous and efficient spatial reference to objects in human-robot interaction situations. This paper presents the iterative, empirically based design of a robotic system that uses a computational model for identifying objects on the basis of a range of spatial reference systems. The efficiency of the system is evaluated by two successive empirical studies involving uninformed users. The linguistic analysis points to the striking variability in speakers' spontaneous strategies and preferences, and it motivates a number of modifications of the computational model.     

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.     

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.     

Landmarks on the move: Producing and understanding references to moving landmarks

There is a general agreement that landmarks in route directions should be perceptually salient and stable objects. Yet, other attributes, such as (animated) motion, can also attract visual attention and make entities salient. In the present study, we investigate if and when speakers refer to moving entities in route directions and how listeners evaluate such instructions. We asked speakers to watch short videos of different crossroads with and without moving landmarks and give directions to listeners, who in turn had to choose a street on which to continue (Experiment 1) or choose the instruction they most preferred among three route directions (Experiment 2). Results reveal that speakers mentioned moving entities, especially when the trajectory was informative for the place where a turn should be taken (Experiment 1). Listeners had no problem understanding instructions with moving landmarks (Experiment 1). Yet, participants chose instructions with stable landmarks more often (Experiment 2). These results are discussed in relation to automatic route directions generation.     

Coordinating signs and eye gaze in the depiction of directions and spatial scenes by fluent and L2 signers of Norwegian Sign Language

The current study investigates the coordination of signs and eye gaze during depictions of directions and spatial scenes by fluent and second language (L2) signers of Norwegian Sign Language. First, findings show that fluent and L2 signers make different choices regarding the perspective they use to depict spatial scenes. Second, there is variation within and across groups in relation to how eye gaze is directed during these depictions. Findings suggest that eye gaze is used to establish a vantage point upon a depicted scene, but L2 learners may not always engage in this type of coordination. This study contributes to our understanding of how visual perspective is depicted in signed languages and has implications for signed language pedagogy.     

'Fine-to-Coarse' Route Planning and Navigation in Regionalized Environments

Environments that are divided into regions lead to hierarchical encoding of space. Such memory structures are known to systematically distort estimates of distance and direction and affect spatial priming and memory recall. Here we present two navigation experiments in virtual environments that reveal an influence of environmental regions on human route planning and navigation behaviour. Following the hierarchical theories of spatial representations, it is argued that environmental regions are explicitly represented in spatial memory and that human route planning takes into account region-connectivity and is not based on place-connectivity alone. We also propose a fine-to-coarse planning heuristic that could account for the empirical data by planning in a representation that uses fine-space information for close locations and coarse-space information for distant locations simultaneously.     

Collaborative Navigation in an Unfamiliar Environment with People Having Different Spatial Aptitudes

This study addressed the issue of collaborative navigation by examining the types of information communicated in the processes of direction giving and receiving between people who guided each other simultaneously to a destination over the cell phone in a novel environment. When paired with a partner whose sense of direction differed greatly from their own, people found the collaboration difficult and took a longer time to verbally direct the partner to the destination. Landmarks that people used in giving navigational instructions differed depending on sense of direction. People with a good sense of direction adjusted route directions to their partners' wayfinding ability. Results from a detailed qualitative analysis of participants' verbal protocols and implications for personalized navigation tools are discussed.     

Language cues in the formation of hierarchical representations of space

We study the role of place and region names in the formation of spatial hierarchies. Representations were probed behaviorally, i.e., by choices between two equidistant routes differing only in the number of regions they touched. Routes crossing fewer region boundaries are preferred over routes crossing more region boundaries. Visual landmark objects from a common semantic category placed in spatial vicinity induce region representations. Here we show that region dependent route preference is reduced if the landmark objects are replaced by signs displaying object names. The effects of explicit region names and linguistic properties of different naming schemes are discussed.     

A Formalism Supplementing Cognitive Semantics Based on Mereology

ABSTRACT

This paper is motivated by and aims to supplement Cognitive Semantics. Details of this latter prominent approach within contemporary linguistic research will not be discussed here. Rather, we focus on a formalization of the concept of Gestalt and provide a formal semantics that can be used to interpret a certain formal language (LM ₀) with respect to a universe of structured wholes (Gestalts). Since a great deal of the analyses of linguistic organization that has been provided by Cognitive Semantics since the mid-1970s is based on the concept of Gestalt, the semantics unfolded in the following may be viewed as an attempt to provide a starting point for supplementing the yet informal analyses of Cognitive Semantics by formal models. Since Gestaltists have talked about Gestalts in terms of parts and wholes, it is a natural step to make use of mereological techniques.     

一种新的共轭增强MUSIC测向算法

提出一种新的测向算法。利用阵列输出的非零时延互相关函数及其共轭形成伪阵列输出,从而得到伪协方差矩阵,对其进行特征分解,利用信号子空间与噪声子空间的正交性,搜索得到的空间谱函数的极大值点对应的角度就是波达方向。仿真实验表明,新算法可对多于阵元数的信号进行测向,其测角精度和分辨力优于MUISC和MUSIC-like算法。     

Modelling Dynamic Spatial Systems in the Situation Calculus

Abstract

We propose and systematically formalise a dynamical spatial systems approach for the modelling of changing spatial environments. The formalisation adheres to the semantics of the situation calculus and includes a systematic account of key aspects that are necessary to realize a domain-independent qualitative spatial theory that may be utilised across diverse application domains. The spatial theory is primarily derivable from the all-pervasive generic notion of “qualitative spatial calculi” that are representative of differing aspects of space. In addition, the theory also includes aspects, both ontological and phenomenal in nature, that are considered inherent in dynamic spatial systems. Foundational to the formalisation is a causal theory that adheres to the representational and computational semantics of the situation calculus. This foundational theory provides the necessary (general) mechanism required to represent and reason about changing spatial environments and also includes an account of the key fundamental epistemological issues concerning the frame and the ramification problems that arise whilst modelling change within such domains. The main advantage of the proposed approach is that based on the structure and semantics of the proposed framework, fundamental reasoning tasks such as projection and explanation directly follow. Within the specialised spatial reasoning domain, these translate to spatial planning/re-configuration, causal explanation and spatial simulation. Our approach is based on the hypothesis that alternate formalisations of existing qualitative spatial calculi using high-level tools such as the situation calculus are essential for their utilisation in diverse application domains such as intelligent systems, cognitive robotics and event-based GIS.