Egocentric Vs Allocentric

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FOREWORD: This thesis presents finding from perspective-taking tasks (see Figs. 2 and 3) that were NOT published in Zhong & Kozhevnikov (2016).

ABSTRACT (Revised):
The current study proposed the existence of two subtypes of survey knowledge/representations: (i) “allocentric-survey” versus (ii) “egocentric-survey”. On one hand, the allocentric-survey representation was proposed as a third person representation abstracted/inferred from knowledge of landmarks, routes, and spatial relations between them. On the other hand, the egocentric-survey representation was proposed as a survey representation formed incrementally through an engagement of egocentric spatial updating, which involves the automatic and continuous updating of transient self-to-object relations as one navigates in space.

Findings from study 1 suggested that egocentric survey representations were qualitatively different from allocentric survey representations as the former preserved information not only about spatial locations, but also about orientation. Two groups of sketchmap drawers exhibited comparable accuracy in representing the spatial layout of the learned route. However, sketchers of egocentric-survey maps were significantly faster on orientation and navigational pointing judgments than sketchers of allocentric-survey maps.

In Study 2, a Navigational Strategy Questionnaire (NSQ) was designed. It included a novel scale assessing a preference for spatial updating navigational strategy and two traditional scales assessing survey based and procedural navigational strategies. Critically, the spatial updating scale exhibited predictive validity in relation to large scale navigational performance and related spatial updating strategy use to the formation of egocentric survey representations.

Common ground is a problematic concept. It is a necessary part of any pragmatic theory because it names the context that speakers take for granted in carrying out a communicative act, or in other words the background against which a signal shows up as a particular pattern of sounds or shapes, words, and social effects. But it is too often either ignored or treated as a stative body of information, a definition which makes it impossible to understand how common ground is used and instantiated in actual conversations. This essay remedies this problem by presenting a novel account of common ground which subsumes most extant theories by approaching the topic separately on each of three levels of explanation. I begin by presenting a dynamical definition of common ground based on elements of Stalnaker’s theory of speaker presupposition, on which common ground is the information presented by a speaker as not-at-issue in the process of carrying out some speech act. I then justify and enrich this approach with a psycholinguistic account of the uses of common ground in conversation based on Clark’s work on joint action, and show that common ground underlies both egocentric and cooperative communication. I then justify and enrich the psycholinguistic account by showing how it is instantiated on a biological level as intra- and interpersonal synergies in a conversation. Finally, I use an analysis of referring to illustrate the relations between these three levels of description, which between presupposition and joint action and between joint action and synergies I take to be one of coherence, clarification, and specifying the object of explanation. In the other direction - from synergies to joint action and joint action to presupposition - the relation is one of grounding and providing naturalistic credentials via mechanistic details. The originality and generality of this explanatory strategy suggest tremendous opportunities for pragmatic research from a dynamical perspective.

To validate the significant relationship found previously between egocentric perspective-taking ability (PTA) and environmental learning, the current study employed an immersive, three-dimensional (3D) virtual reality PTA task coupled with in-depth assessments of environmental learning. Based on structural equation modelling, the combined use of the 3D perspective-taking task with its desktop-based computerized counterpart predicted environmental learning (based on two pointing-to-landmarks tasks, and one shortcut-finding/navigation task) with a high standardized regression weight (0.83) in terms of pointing accuracy and goal proximity (i.e., walking distance to the point-of-origin). Correlational analyses further implicated the 3D perspective-taking task to be a more sensitive measurement of egocentric perspective-taking ability. These findings were interpreted with regards to the spatial processes engendering PTA and the need for further investigations into the functional roles of different spatial or imagery strategies for perspective-taking COPYRIGHT CC-BY-NC-ND 4.0, J. Y. ZHONG 2016, GEORGIA INSTITUTE OF TECHNOLOGY, NATIONAL UNIVERSITY OF SINGAPORE, US COPYRIGHT OFFICE REG. NO.: TXu-0002-053-351]. ENDNOTE: This manuscript is protected under U.S. and international copyright laws. The author reserves the right to legal actions to protect the contents featured in this paper.

According to actionism (Noë 2010), perception constitutively depends on implicit knowledge of the way sensory stimulations vary as a consequence of the perceiver’s self-movement. My aim in this contribution is to develop an alternative conception of the role of action in perception present in the work of Gareth Evans using resources provided by Ruth Millikan’s biosemantic theory of mental representation.

Isovist analysis is useful tool for understanding how individuals perceive and act in space. It is often used in space syntax research as part of a set of techniques that examine users' visibility of space. Traditionally, isovists represent the optimal viewshed from any given location; when working with real-world spaces, however, there may be obstacles that obscure the optimal isovist. This paper explores the relevance of first-person isovists that are drawn from what is actually (and not only theoretically) visible in the scene. A candidate measure, termed " choice zones " , is evaluated. The paper argues that for real-world studies examining the social use of space, it may be desirable to complement traditional viewshed analyses with ones that take an egocentric perspective. The art of architectural representation is to depict the 3D properties of a space in a 2D form in such a way, that they aid people to imagine what a space may look or feel like. People with high spatial abilities (eg. architects) find it easy to switch between different drawings projections (eg. plan vs. section) and between drawings viewpoints (eg. allocentric vs. egocentric). Viewsheds can be a useful way for analysing the geometric properties of a space, as they are a simple abstraction: they represent the boundaries of any space as a 2D polygon, measured from a generating location. In their traditional form, viewsheds tend to be an allocentric form of analysis. This paper examines the merit of representing viewsheds from an egocentric perspective. It discusses what the drawbacks of the traditional allocentric form are, and how these can be addressed by using an egocentric approach. The paper begins with a discussion of existing representations and measures. It goes on to discuss a newly proposed measure, " choice zones " , as a way of defining the first-person isovist. The paper ends with a discussion of the value of such a measure for the space syntax community. 2. Background Viewsheds are often used in architectural analyses to convey what can be seen at any given point. A particular type of viewshed, or vista, has proved especially relevant for the analysis of the built environment: an isovist is a 2D polygon, taken at a stated height (commonly either floor level or eye-height) that represents the visible area from a point (the generating location of the isovist) (Figure 1). The aim of this section is to give an overview of some of the key concepts and measures used in viewshed analysis to date.

As tasks in Virtual and Augmented Reality applications become increasingly complex, there is a need to better organize information or virtual objects within the virtual environment. For example, 3D Widget or menus may need to hide information from the user until it is needed. Users may need to organize their own virtual objects or tools by storing them until usage is needed or carry with them to another location. For these scenarios and others, there may be benefits to associating or storing virtual objects in relation to one’s own avatar (Egocentric) or in relation to the other virtual objects in the environment (Exocentric). This paper presents the results of a user study comparing the effects of Egocentric and Exocentric Virtual Object Storage Techniques on cognition in a virtual envi- ronment. Participants performed a task that enabled them to store virtual objects using different Virtual Object Storage Techniques. As participants completed their tasks, we measured task and cognition performance. We found that the egocentric technique improves task performance, increases accuracy, and reduces cognitive workload during memory task for virtual object storage in comparison to the exocentric technique in a virtual environment.

In everyday living, one of our most fundamental human needs entails in knowing the objects and places around us and having the capacity to freely roam about this environment. A great part of our lives is spent on travelling from one place to another, either within the same environment or between environments. This spontaneous activity stems from our adaptive needs to seek shelter, to find food, and to escape from harm's way. It is summarized by the word "navigation," which is characterized by the "planning of travel through the environment, updating position and orientation during travel, and in the event of becoming lost, reorienting and reestablishing travel towards the destination" (Loomis et al., 1999, p. 125). More precisely, navigation has been conceived to comprise of the behavioral component of locomotion, and the cognitive component of wayfinding (Montello, 2001, 2005). Locomotion refers to the physical movement from one place to another that is usually guided by vision. It is typified by activities such as steering, obstacle avoidance, and approaching objects. On the other hand, wayfinding involves the tactical and strategic aspects of navigation. It encapsulates decision-making or reasoning, route planning, and the formation of environmental representation for the exploration of places beyond the line of sight. With these definitions in mind, this paper addresses how individuals differ with regard to the environmental representations formed after travelling a novel route, and how different navigational strategies contribute to the formation of these distinct types of environmental representations.

Spatial memory is the metaphorical hook on which our everyday experiences hang. One way of thinking about the development of spatial memory is as a progression from (a) egocentric (self-based) codings to (b) simple allocentric (world-based) codings relative to just one spatial reference to (c) codings using multiple allocentric spatial references together. We re-examined that timeline in a simplified virtual environment. Children aged 3-5 years saw a virtual penguin in relation to symmetric landmarks and then recalled its location after being ‘teleported’ to a new viewpoint. We found that children aged 3.5-4.0 years successfully used a single-landmark recall strategy, which is even younger than our previous work with a more cue-rich environment (Negen, Heywood-Everett, Roome & Nardini, 2017). Children succeeded at multiple-landmark allocentric recall at age 4.0-4.5 years, which is also younger than our previous findings in a more cue-rich environment. In addition, an inhibition measure was found to be a significant predictor of single-landmark strategies and recall accuracy. These findings suggest that single- and multi-landmark allocentric recall emerge earlier than previously thought, and that executive functions may form a bottleneck in environments that are not purposefully simplified to have fewer cues than naturalistic environments.

Previous research has shown an effect of handle-response correspondence on key-press responses when participants judged the upright or inverted orientation of photographed one-handled graspable objects. In three experiments, we explored whether this effect still holds for symmetric graspable objects that are usually grasped by two hands (i.e. two-handled objects; e.g. shears). In Experiments 1 and 2, participants were required to perform a between-hand response in order to categorize cooking or amusement objects appearing as grasped from either an allocentric (Experiment 1) or an egocentric perspective (Experiment 2). In Experiment 3, they were required to perform a within-hand response to categorize the same stimuli appearing as grasped from an egocentric perspective. Across all three experiments, results showed that categorization was more difficult when the objects were displayed as grasped on the opposite side than the response rather than on the same side. We discuss the implications of these results for theories of action potentiation and spatial coding and suggest that different mechanisms may be recruited depending on the required action (i.e. response mode).

Neglect patients show contralesional deficits in egocentric and object-centred visuospatial tasks. The extent to which these different phenomena are modulated by sensory stimulation remains to be clarified. Subliminal galvanic vestibular stimulation (GVS) induces imperceptible, polarity-specific changes in the cortical vestibular systems without the unpleasant side effects (nystagmus, vertigo) induced by caloric vestibular stimulation. While previous studies showed vestibular stimulation effects on egocentric spatial neglect phenomena, such effects were rarely demonstrated in object-centred neglect. Here, we applied bipolar subsensory GVS over the mastoids (mean intensity: 0.7 mA) to investigate its influence on egocentric (digit cancellation, text copying), object-centred (copy of symmetrical figures), or both (line bisection) components of visual neglect in 24 patients with unilateral right hemisphere stroke. Patients were assigned to two patient groups (impaired vs. normal in the respective task) on the basis of cutoff scores derived from the literature or from normal controls. Both groups performed all tasks under three experimental conditions carried out on three separate days: (a) sham/baseline GVS where no electric current was applied, (b) left cathodal/right anodal (CL/AR) GVS and (c) left anodal/right cathodal (AL/CR) GVS, for a period of 20 min per session. CL/AR GVS significantly improved line bisection and text copying whereas AL/CR GVS significantly ameliorated figure copying and digit cancellation. These GVS effects were selectively observed in the impaired-but not in the unimpaired patient group. In conclusion, subliminal GVS modulates ego-and object-centred components of visual neglect rapidly. Implications for neurorehabilitation are discussed.