Showing papers on "Representation (systemics) published in 1993"

Parts and wholes in face recognition

Abstract: Are faces recognized using more holistic representations than other types of stimuli? Taking holistic representation to mean representation without an internal part structure, we interpret the available evidence on this issue and then design new empirical tests. Based on previous research, we reasoned that if a portion of an object corresponds to an explicitly represented part in a hierarchical visual representation, then when that portion is presented in isolation it will be identified relatively more easily than if it did not have the status of an explicitly represented part. The hypothesis that face recognition is holistic therefore predicts that a part of a face will be disproportionately more easily recognized in the whole face than as an isolated part, relative to recognition of the parts and wholes of other kinds of stimuli. This prediction was borne out in three experiments: subjects were more accurate at identifying the parts of faces, presented in the whole object, than they were at identifying ...

Things That Make Us Smart: Defending Human Attributes In The Age Of The Machine

Abstract: * A Human-Centered Technology * Experiencing the World * The Power of Representation * Fitting the Artifact to the Person * The Human Mind * Distributed Cognition * A Place for Everything, and Everything in Its Place * Predicting the Future * Soft and Hard Technology * Technology Is Not Neutral

What Is a Knowledge Representation

Abstract: Although knowledge representation is one of the central and, in some ways, most familiar concepts in AI, the most fundamental question about it -- What is it? -- has rarely been answered directly. Numerous papers have lobbied for one or another variety of representation, other papers have argued for various properties a representation should have, and still others have focused on properties that are important to the notion of representation in general. In this article, we go back to basics to address the question directly. We believe that the answer can best be understood in terms of five important and distinctly different roles that a representation plays, each of which places different and, at times, conflicting demands on the properties a representation should have. We argue that keeping in mind all five of these roles provides a usefully broad perspective that sheds light on some longstanding disputes and can invigorate both research and practice in the field.

Neuronal mechanisms of object recognition

Abstract: Recognition of objects from their visual images is a key function of the primate brain. This recognition is not a template matching between the input image and stored images like the vision in lower animals but is a flexible process in which considerable change in images, resulting from different illumination, viewing angle, and articulation of the object, can be tolerated. Recent experimental findings about the representation of object images in the inferotemporal cortex, a brain structure that is thought to be essential for object vision, are summarized and discussed in relation to the computational frames proposed for object recognition.

Representational content in humans and machines

Abstract: This article focuses on the problem of representational content. Accounting for representational content is the central issue in contemporary naturalism: it is the major remaining task facing a naturalistic conception of the world. Representational content is also the central barrier to contemporary cognitive science and artificial intelligence: it is not possible to understand representation in animals nor to construct machines with genuine representation given current (lack of) understanding of what representation is. An elaborated critique is offered to current approaches to representation, arguing that the basic underlying approach is, at root, logically incoherent, and, thus, that standard approaches are doomed to failure. An alternative model of representation— interactivism is presented that avoids or solves the problems facing standard approaches. Interactivism is framed by a version of functionalism, and a naturalization of that functionalism completes an outline of a naturalization of r...

The cognizer's innards: A psychological and philosophical perspective on the development of thought.

Abstract: A travers l'analyse du comportement cognitif des enfants, l'A. etudie le processus de redescription representative qui semble indissociable des modeles connexionnistes complexes ou d'un systeme connexionniste-symbolique

Method for representation of knowledge in a computer as a network database system

Abstract: A system for knowledge representation in a computer, together with the ability to recognize, store and use patterns in the knowledge representation, together with the ability for Natural Language Interaction with the knowledge representation system, together with systems to automatically transform information in the knowledge representation into a multitude of documents or other human interpretable displays in a plurality of different formats or views. User interaction with the knowledge representation through the view documents is achievable through a multitude of various possible formats. The Knowledge Representation system defines a novel database engine constituting a method for modeling knowledge as a network of concepts and a plurality of relationships between the concepts comprising the network. Each concept is represented as a record in the database which is identified by a unique record reference number. The unique record reference numbers are stored within the records comprising the database to record the plurality of relationships between concepts.

On the importance of time—a temporal representation of sound

Abstract: 5 1 INTRODUCTION The human auditory system has an amazing ability to separate and understand sounds. We believe that temporal information plays a key role in this ability, more important than the spectral information that is traditionally emphasized in hearing science. In many hearing tasks, such as describing or classifying single sound sources, the underlying mathematical equivalence makes the temporal versus spectral argument moot. We show how the nonlinear-ity of the auditory system breaks this equivalence, and is especially important in analyzing complex sounds from multiple sources of different characteristics. The auditory system is inherently nonlinear. In a linear system, the component frequencies of a signal are unchanged, and it is easy to characterize the amplitude and phase changes caused by the system. The cochlea and the neural processing that follow are more interesting. The bandwidth of a cochlear " filter " changes at different sound levels, and neurons change their sensitivity as they adapt to sounds. Inner Hair Cells (IHC) produce nonlinear rectified versions of the sound, generating new frequencies such as envelope components. All of these changes make it difficult to describe auditory perception in terms of the spectrum or Fourier transform of a sound. One characteristic of an auditory signal that is undisturbed by most nonlinear transformations is the periodicity information in the signal. Even if the bandwidth, amplitude, and phase characteristics of a signal are changing, the repetitive characteristics do not. In addition, it is very unlikely that a periodic signal could come from more than one source. Thus the auditory system can safely assume that sound fragments with a consistent periodicity can be combined and assigned to a single source. Consider, for example, a sound formed by opening and closing the glottis four times and filtering the resulting puffs of air with the vocal resonances. After nonlinear processing the lower auditory nervous system will still detect four similar events which will be heard and integrated as coming from a voice. The duplex theory of pitch perception, proposed by Licklider in 1951 [11] as a unifying model of pitch perception, is even more useful as a model for the extraction and representation of temporal structure for both periodic and non-periodic signals. This theory produces a movie-like image of sound which is called a correlogram. We believe that the correlogram, like other representations that summarize the temporal information in a signal, is an important tool for understanding …

An empirical analysis of optimization techniques for terminological representation systems : or: 'Making KRIS get a move on'

Abstract: We consider different methods of optimizing the classification process of terminological representation systems, and evaluate their effect on three different types of test data Though these techniques can probably be found in many existing systems, until now there has been no coherent description of these techniques and their impact on the performance of a system One goal of this paper is to make such a description available for future implementors of terminological systems Building the optimizations that came off best into the KRIS system greatly enhanced its efficiency

Social representations and social identity

Abstract: Doise (in press) has emphasised that researchers have focused empirical work on only one aspect of the theory of social representations. They have mainly been concerned either with describing the content of existing representations or they have been interested in examining how anchoring and objectification operate. They have left largely unexplored Moscovici’s hypotheses concerning the ways in which, at the level of the metasystem, social groups generate representations which serve group purposes. Representations serve different types of group interest and Moscovici describes three: diffusion, propagation and propaganda. Representations serving these three communicative purposes have different structures and organisation. They differ particularly in the extent to which they are consensually shared within a group or a subgroup. The defining property of a social representation is not simply that it should be shared. The predicted internal structure of the representation and the extent to which it is dispersed within a recognisable group or social category will depend upon the functions it is serving. This has major implications for the empirical approaches which should be adopted when exploring social representations. It suggests that intra-group dynamics and inter-group relations will direct or channel the formation of any specific social representation. This requires that the theorist should formulate clear predictions concerning the structure of a representation as revealed in the thought, utterances and action of the individual in relation to that individual’s position in a group. It calls for the analysis of likely implications of changes in group structure for the representation. It necessitates consideration of the inter-group processes which promulgate the social representation and afford it a venue in which to be used. It emphasises that representations are embedded in complex representational networks and that they are liable to change, whether subtle or global, as a result of their relationships to each other.

Functional representation as design rationale

Abstract: The functional representation (FR) framework, which captures the causal component of a design rationale (DR), is described. FR encodes the designer's account of the causal processes in the device that culminate in achieving its function. The representation makes explicit the components' roles in the causal process. The limitations of FR as a design rationale and the limitations of the current repertoire of representational primitives in FR for capturing the causal component are discussed. >

The Imagery Debate

Abstract: One central debate in cognitive science is over imagery. Do images constitute, or constitute evidence for, a distinctive, depictive form of mental representation? The most sophisticated advocacy of this view has been developed by Kosslyn and his coworkers. This paper focuses on his position and argues (i) that though Kosslyn has not developed a satisfactory account of depiction, there is nothing in principle unintelligible about the idea of depictive neural representation, but (ii) Kosslyn's model of imagery rescues the intelligibility of pictorialism at the cost of its explanatory power.

The complex EGI: a new representation for 3-D pose determination

Abstract: The complex extended Gaussian image (CEGI), a 3D object representation that can be used to determine the pose of an object, is described. In this representation, the weight associated with each outward surface normal is a complex weight. The normal distance of the surface from the predefined origin is encoded as the phase of the weight, whereas the magnitude of the weight is the visible area of the surface. This approach decouples the orientation and translation determination into two distinct least-squares problems. The justification for using such a scheme is twofold: it not only allows the pose of the object to be extracted, but it also distinguishes a convex object from a nonconvex object having the same EGI representation. The CEGI scheme has the advantage of not requiring explicit spatial object-model surface correspondence in determining object orientation and translation. Experiments involving synthetic data of two polyhedral and two smooth objects are presented to illustrate the feasibility of this method. >

Representation, Similarity, and the Chorus of Prototypes

Abstract: It is proposed to conceive of representation as an emergent phenomenon that is supervenient on patterns of activity of coarsely tuned and highly redundant feature detectors. The present preliminary study appears to indicate that this concept of representation is computationally viable, and is compatible with psychological and neurobiological data.

Content-based depictions of computer icons

Abstract: A means and method for generating and displaying a contentbased depiction of a standard icon on the display of a computer is described. The depiction is generated upon the occurrence of predetermined events, such as the closure of the document or file associated with the icon, and is displayed in either a static or animated form in place of the standard icon in response to selection signals from a selection device. A single content-based depiction of an icon is generated by creating a representation of the object (file or document) to be depicted, and translating this representation into a scaled-down replica of the representation. This representation may be in the form of a bit-map, a full-scale image, etc. The replica is created by partitioning the representation into a number of equal segments, measuring the percentages of different colors (black and white, gray scale, or color) within each segment, and assigning a single color value to each display element or pixel of the replica based upon the color percentage measured from each corresponding segment of the representation. Animated depictions are created by forming a number of different replicas for each representation to be depicted and then displaying those replicas in a serial sequence to create an animated depiction of the representation. Like the icons these depictions replace when selected, the depictions would be movable to any position on the display through use of the mouse.