The article contributes to the quest to relate global data on brain and behavior (e.g. from PET, Positron Emission Tomography, and fMRI, functional Magnetic Resonance Imaging) to the underpinning neural networks. Models tied to human brain imaging data often focus on a few "boxes" based on brain regions associated with exceptionally high blood flow, rather than analyzing the cooperative computation of multiple brain regions. For analysis directly at the level of such data, a schema-based model may be most appropriate. To further address neurophysiological data, the Synthetic PET imaging method uses computational models of biological neural circuitry based on animal data to predict and analyze the results of human PET studies. This technique makes use of the hypothesis that rCBF (regional cerebral blood flow) is correlated with the integrated synaptic activity in a localized brain region. We also describe the possible extension of the Synthetic PET method to fMRI. The second half of the...

We show that by introducing an appropriate schema concept and exploiting the higher-level features of a resonance function in a neural network it is possible to define a form of nonmonotonic inference relation between the input and the output of the network. This inference relation satisfies some of the most fundamental postulates for nonmonotonic logics. The construction presented in the paper is an example of how symbolic features can emerge from the subsymbolic level of a neural network.

Hypertext is a computer-supported medium for information in which many interlinked documents are displayed with their links on a high-resolution computer screen. The links may be directly activated by a pointing device such as a mouse, which causes the document referenced by the link to appear instantly in a new window on the screen. While the concepts of hypertext are not new, the technology to make it effective is new. This paper reviews most of the existing hypertext systems, and then explores in some detail the fundamental features of hypertext and some of the design options in constructing hypertext systems. The advantages and disadvantages of hypertext are discussed in terms of four major application categories: macro literary systems, problem exploration systems, structured browsing systems, and systems developed to explore hypertext technology.

The most vexing question in natural language generation is 'what is the source'--what do speakers start from when they begin to compose an utterance? Theories of generation in the literature differ markedly in their assumptions. A few start with an unanalyzed body of numerical data (e.g. Bourbeau et al. 1990; Kukich 1988). Most start with the structured objects that are used by a particular reasoning system or simulator and are cast in that system's representational formalism (e.g. Hovy 1990; Meteer 1992; R6sner 1988). A growing number of systems, largely focused on problems in machine translation or grammatical theory, take their input to be logical formulae based on lexical predicates (e.g. Wedekind 1988; Shieber et al. 1990). The lack of a consistent answer to the question of the generator's source has been at the heart of the problem of how to make research on generation intelligible and engaging for the rest of the computational linguistics community, and has complicated efforts to evaluate alternative treatments even for people in the field. Nevertheless, a source cannot be imposed by fiat. Differences in what information is assumed to be available, its relative decomposition when compared to the "packaging " available in

How can artificial or natural agents autonomously gain understanding of its own internal (sensory) state? This is an important question not just for physically embodied agents but also for software agents in the information technology environment. In this paper, we investigate this issue in the context of a simple biologically motivated sensorimotor agent. We observe and acknowledge, as many other researchers do, that action plays a key role in providing meaning to the sensory state.

. The concept of schema and some general characteristics of models using schemata are discussed. It is shown by computer simulations how a combination of a number of simple neural circuits are capable of performing actions similar to those commonly attributed to schemata, especially self-organization of a representational code, recognition of spatial and temporal structure, adaptive performance and semantic constraint satisfaction. 1. INTRODUCTION What are the basic units of cognitive processing? The so called Classical Theories (Fodor & Pylyshyn, 1988) argue that these units are symbols together with symbolic processes. On the other hand, the Connectionist School argues that we should approach cognition at another level and study how neuronlike elements interact to produce collective effects (Rumelhart et. al. 1986). Both camps seem to assume that the other is totally wrong. Yet, there is no doubt that human behaviour exhibits examples of both the symbol processing capabilities of t...

Abstract. The COTESYS cluster of excellence a investigates cognition for technical systems such as vehicles, robots, and factories. Cognitive technical systems (CTS) are information processing systems equipped with artificial sensors and actuators, integrated and embedded into physical systems, and acting in a physical world. They differ from other technical systems as they perform cognitive control and have cognitive capabilities. Cognitive control orchestrates reflexive and habitual behavior in accord with longterm intentions. Cognitive capabilities such as perception, reasoning, learning, and planning turn technical systems into systems that “know what they are doing”. The cognitive capabilities will result in systems of higher reliability, flexibility, adaptivity, and better performance. They will be easier to interact and cooperate with.

an 1984). Of related interest is a phenomenon of lexical memory which may be dubbed "natural keyword abstraction ": when given a list of words such as "chocolate, bitter, cake, honey, sour", subjects recall the semantically related word "sweet" together with the actually presented words, or even with a higher probability (Roediger & McDermott 1995). There have been a number of ways whereby psychologists and neuropsychologists have attempted to deal with the general human faculty of memorization. Again, recent accounts have found evidence for a distinction between general, "source-free" information encoding and the creation of full, episodic memories that include source encoding, personal memory, and emotive experience (Eichenbaum 1997). In fact, source encoding, i.e. the verbatim retention of linguistic material, is an additional process which is rarely used in the context of story understanding; the activation of schematic memory leading to natural summarization of a text is the norm.

Abstract. The concept of schema and some general characteristics of models using schemata are discussed. It is shown by computer simulations how a combination of a number of simple neural circuits are capable of performing actions similar to those commonly attributed to schemata, especially self-organization of a representational code, recognition of spatial and temporal structure, adaptive performance and semantic constraint satisfaction. 1.

Part of understanding a foreign language text involves the ability to solve lexical ambiguities that are not found in the first language. Traditionally, it has been claimed that the resolution of lexical ambiguity is done through schema activation. The hypothesis investigated here is that collocation may be a more dependable source than the reader’s previous knowledge. Twenty ambiguous words were selected, disambiguated through rules based on collocation, and then tested with a concordancer, using an English language corpus of 20,000,000 words of expository text. The results showed that more than 94% of the ambiguities were solved by using syntactic and semantic restrictions between the ambiguous word and a related disambiguating word that co-occurred in the same sentence. The interpretation offered for these results is that collocation replaces with many advantages the use of encyclopedic knowledge to solve lexical ambiguities.