Reinforcing connectionism: learning the statistical way

Connectionism's main contribution to cognitive science will prove to be the renewed impetus it has imparted to learning. Learning can be integrated into the existing theoretical foundations of the subject, and the combination, statistical computational theories, provide a framework within which many connectionist mathematical mechanisms naturally fit. Examples from supervised and reinforcement learning demonstrate this. Statistical computational theories already exist for certainn associative matrix memories. This work is extended, allowing real valued synapses and arbitrarily biased inputs. It shows that a covariance learning rule optimises the signal/noise ratio, a measure of the potential quality of the memory, and quantifies the performance penalty incurred by other rules. In particular two that have been suggested as occuring naturally are shown to be asymptotically optimal in the limit of sparse coding. The mathematical model is justified in comparison with other treatments whose results differ. Reinforcement comparison is a way of hastening the learning of reinforcement learning systems in statistical environments. Previous theoretical analysis has not distinguished between different comparison terms, even though empirically, a covariance rule has been shown to be better than just a constant one. The workings of reinforcement comparison are investigated by a second order analysis of the expected statistical performance of learning, and an alternative rule is proposed and empirically justified. The existing proof that temporal difference prediction learning converges in the mean is extended from a special case involving adjacent time steps to the general case involving arbitary ones. The interaction between the statistical mechanism of temporal difference and the linear representation is particularly stark. The performance of the method given a linearly dependent representation is also analysed

COLAB : a hybrid knowledge representation and compilation laboratory

Knowledge bases for real-world domains such as mechanical engineering require expressive and efficient representation and processing tools. We pursue a declarative-compilative approach to knowledge engineering. While Horn logic (as implemented in PROLOG) is well-suited for representing relational clauses, other kinds of declarative knowledge call for hybrid extensions: functional dependencies and higher-order knowledge should be modeled directly. Forward (bottom-up) reasoning should be integrated with backward (top-down) reasoning. Constraint propagation should be used wherever possible instead of search-intensive resolution. Taxonomic knowledge should be classified into an intuitive subsumption hierarchy. Our LISP-based tools provide direct translators of these declarative representations into abstract machines such as an extended Warren Abstract Machine (WAM) and specialized inference engines that are interfaced to each other. More importantly, we provide source-to-source transformers between various knowledge types, both for user convenience and machine efficiency. These formalisms with their translators and transformers have been developed as part of COLAB, a compilation laboratory for studying what we call, respectively, "vertical\u27; and "horizontal\u27; compilation of knowledge, as well as for exploring the synergetic collaboration of the knowledge representation formalisms. A case study in the realm of mechanical engineering has been an important driving force behind the development of COLAB. It will be used as the source of examples throughout the paper when discussing the enhanced formalisms, the hybrid representation architecture, and the compilers

IT-Gestützte Kollaborative Kreativität

Companies and organizations must constantly evolve in order to stay competitive in the marketplace. An important role is played by innovations that ensure this continuous corporate success. Producing innovations depends strongly on creativity, which is why active support makes sense and is worthwhile. Creativity can be supported by information technology and is most effective in teams and groups. Collaboration and the consideration of different collaboration mechanisms play an equally important role in this context as the active support by information technology. This dissertation deals with the question of how information systems can be designed in order to use information technology to actively support creativity and that collaborative creativity processes are promoted. With the help of a systematic literature review, current creativity support systems were examined and the necessity of research was explained. A design-oriented approach was then used to develop and evaluate various approaches that address the research question. A total of 25 scientific articles were produced, five of which are included in this dissertation. Various conducted studies show the additional value of active support through information technology and provide design guidelines for better support of collaborative creativity.Unternehmen und Organisationen müssen sich ständig weiterentwickeln, um am Markt beständig zu sein und geschäftsfähig zu bleiben. Eine wichtige Rolle sind Innovationen, die diesen kontinuierlichen Unternehmenserfolg sicherstellen. Innovationen zu produzieren hängt stark von Kreativität ab, weshalb eine aktive Unterstützung sinnvoll und lohnenswert ist. Kreativität kann dabei durch Informationstechnik unterstützt werden und entfaltet vor allem in Teams und Gruppen ihre größte Wirkung. Kollaboration und die Betrachtung unterschiedlicher Kollaborationsmechanismen spielt in diesem Kontext gleichermaßen eine wichtige Rolle, wie die aktive Unterstützung durch Informatikstechnik. Die vorliegende Dissertation beschäftigt sich mit der Fragestellung, wie Informationssysteme gestaltet werden können, um einerseits Informationstechnik so einzusetzen, dass sie aktiv Kreativität unterstützt, andererseits so gestaltet werden sollte, dass kollaborative Kreativitätsprozesse gefördert werden. Mit Hilfe einer systematischen Literaturanalyse wurden dabei aktuelle Kreativitätsunterstützungsysteme untersucht und die Notwendigkeit der Forschung dargelegt. Mit einem gestaltungsorientierten Vorgehen wurden daraufhin unterschiedliche Ansätze entwickelt und evaluiert, die die Fragestellung adressieren. Dabei sind insgesamt 25 wissenschaftliche Artikel entstanden, von welchen fünf in diese Dissertation eingebunden sind. Unterschiedliche durchgeführte Studien zeigen daraufhin den Mehrwert von aktiver Unterstützung durch Informationstechnik auf und geben Gestaltungsrichtlinien zur besseren Unterstützung von kollaborativer Kreativität

Rhetorical memory, synaptic mapping, and ethical grounding

This research applies neuroscience to classical accounts of rhetorical memory, and argues that the physical operations of memory via synaptic activity support causal theories of language, and account for individual agency in systematically considering, creating, and revising our stances toward rhetorical situations. The dissertation explores ways that rhetorical memory grounds the work of the other canons of rhetoric in specific contexts, thereby expanding memory's classical function as "custodian" to the canons. In this approach, rhetorical memory actively orients the canons as interdependent phases of discursive communicative acts, and grounds them in an ethical baseline from which we enter discourse. Finally, the work applies its re-conception of rhetorical memory to various aspects of composition and Living Learning Community educational models via practical and deliberate interpretation and arrangement of our synaptic "maps.

Re-thinking lifelogging : designing human-centric prosthetic memory devices.

Building Prosthetic Memory (PM) technology has been an active research area for the past few decades, with the primary aim in supporting Organic Memory (OM) in remembering everyday events and experiences. Through building and evaluating new PM tools, this thesis attempts to explore how and when PM tools are used to help OM in everyday memory tasks. The focus of this thesis is to investigate PM tools as an extension of, or a supplement to, OM and to understand why people choose to use PM as opposed to their OM to help them retrieve information. Further aims of this thesis are to investigate the role of Metamemory and social processes. Finally, the work aims to support Autobiographical memory through building new PM tools. The studies apply mixed experimental and naturalistic methods, and include 3 controlled lab studies and 3 field trials involving a total of 217 participants. Overall, there were 5 new PM devices built and evaluated in long-term and controlled contexts. Results obtained through lab studies suggest that PM and OM function in a synergetic relationship. In particular, use of PM increases when OM is particularly weak and this interaction is mediated by organic Metamemory processes. PM properties also have an influence - people prefer efficient over accurate PM devices. Furthermore, PM cues help in two ways: 1) at encoding to help focus OM; and 2) at retrieval to cue partially remembered information. Longer term studies also reveal that PM is not used to substitute for OM. Instead users prefer to use recordings to access specific parts of a lecture rather than listen to the whole thing. Such tools are extensively used by non-native speakers, although only native speakers' coursework benefits from usage. PM tools that support social summarisation demonstrate that people exploit social feedback and cues provided by other users and that these improve recall. IV Finally, evaluations of new autobiographical memory tools show that people upload mementos based on their importance. There is evidence for preference for mementos that are associated with other people and home. I conclude with a discussion of the design and theory implications of this work