Full Publications

    In Press/Submitted

  1. L. Gabora, K. Kitto. Concept Combination and the Origins of Complex Cognition. Forthcoming: The Origins of Mind, a volume in the Springer book series in Biosemiotics [http://www.springer.com/series/7710].

  2. K. Kitto, P. Bruza. Tests and models of non-compositional concepts. Accepted: Cognitive Science 2012.

    This paper proposes a well developed mathematical apparatus to determine whether a conceptual combination is compositional, or not. Within cognitive science, systematicity and productivity appear to require that conceptual representation should be compositional, but the need to represent prototypical information implies that concepts must be represented non-compositionally. As a consequence, the question of under what conditions conceptual representation is compositional (or not) remains debatable. By drawing on general probabilistic methods developed in quantum theory to test whether a system is decomposable, or not, a formal test is proposed that can determine whether a specific conceptual combination is compositional. This test examines a joint probability distribution modelling the combination, asking whether or not it is factorizable. Empirical studies indicate that some combinations should be considered as non-compositional.

  3. K. Kitto, P. Bruza, L. Gabora. A quantum information retrieval approach to memory. In Press: 2012 International Joint Conference on Neural Networks (IJCNN).

    As computers approach the physical limits of information storable in memory, new methods are needed to advance computing power. We propose proposed is a quantum vector-based approach to memory which may overcome the difficulty of mapping symbolic to subsymbolic representations. The approach is inspired by the structure of human memory and incorporates elements of Gardenfors' vector-based Conceptual Space approach and Humphries et. al's matrix model of memory. Though in its infancy, the quantum information retrieval approach can provide not just exceptionally high density memory storage but creative capacities as well.

  4. P.D. Bruza, K. Kitto, B. Ramm, L. Sitbon. The non-decompositionality of concept combinations.

    Concept combinations form a vital component in the creation of a broad range of compound phrases. They range considerably in type, from the everyday ``black cat" to novel compound nominals such as ``cactus fish". The prevailing view in both cognitive science and computational linguistics is that the semantics of concept combination are compositional i.e., can be determined from the semantics of the constituents. However, this assumption has been questioned in both cognitive science and philosophy. This article provides a new formal framework for studying the semantics of concept combination. Utilizing probabilistic methods developed for analyzing composite systems in quantum theory, we show that it is possible to classify concept combinations as having ``classically compositional", ``pseudo-classically non-compositional" or ``non-classically non-compositional" semantics by determining whether the joint probability distribution modeling the combination is factorisable, or not. An empirical study of twelve bi-ambiguous concept combinations shows how (non-)compositional semantic analysis can be applied using these probabilistic methods.

    Published

  5. K. Kitto, P. Bruza. (2012) Non-compositional concepts and quantum tests. Proceedings of The Foundations of Probability and Physics-6 (FPP6) conference, Eds. D'Ariano, Fei, Haven, et al., AIP Conf. Proc. 1424, pp. 458-462.

    Compositionality is a frequently made assumption in linguistics, and yet many human subjects reveal highly non-compositional word associations when confronted with novel concept combinations. This article will show how a non-compositional account of concept combinations can be supplied by modelling them as interacting quantum systems.

  6. Bruza, P.D., Kitto, K., Ramm, B., Sitbon, L., Blomberg, S. and Song, D. (2012) Quantum-like non-separability of concept combinations, emergent associates and abduction. Logic Journal of the IGPL, 20(2):445-457.

    Consider the concept combination "pet human". In word association experiments, human subjects produce the associate "slave" in relation this combination. The striking aspect of this associate is that it is not produced as an associate of "pet", or "human" in isolation. In other words, the associate "slave" seems to be emergent. Such emergent associations sometimes have a creative character and cognitive science is largely silent about how we produce them. Departing from a dimensional model of human conceptual space, this article will explore concept combinations, and will argue emergent associations are related to abductive reasoning within conceptual space, that is, below the symbolic level of cognition. A tensor based approach is used to model concept combinations allowing such combinations to be formalized as interacting quantum systems. Free association norm data is used to motivate the underlying basis of the conceptual space. It is shown by analogy how concept combinations may behave like quantum-entangled (non-separable) particles. Two methods of analysis were presented for empirically validating the presence of non-separable concept combinations in human cognition. One method is based on quantum theory and another based on comparing a joint (true theoretic) probability distribution with another distribution based on a separability assumption using a chi-square goodness-of-fit test. Although these methods were inconclusive in relation to an empirical study of bi-ambiguous concept combinations, avenues for further refinement of these methods are identified.

  7. K. Kitto, F. Boschetti, P. Bruza. (2011) The geometric modelling of social frames and contexts Proceedings of the 2011 International Congress on Modelling and Simulation (MSSANZ MODSIM), p2975-2981.

    How do humans respond to their social context? This question is becoming increasingly urgent in a society where democracy requires that the citizens of a country help to decide upon its policy directions, and yet those citizens frequently have very little knowledge of the complex issues that these policies seek to address. Frequently, we find that humans make their decisions more with reference to their social setting, than to the arguments of scientists, academics, and policy makers. It is broadly anticipated that the agent based modelling (ABM) of human behaviour will make it possible to treat such social effects, but we take the position here that a more sophisticated treatment of context will be required in many such models. While notions such as historical context (where the past history of an agent might affect its later actions) and situational context (where the agent will choose a different action in a different situation) abound in ABM scenarios, we will discuss a case of a potentially changing context, where social effects can have a strong influence upon the perceptions of a group of subjects. In particular, we shall discuss a recently reported case where a biased worm in an election debate led to significant distortions in the reports given by participants as to who won the debate (Davis et al 2011). Thus, participants in a different social context drew different conclusions about the perceived winner of the same debate, with associated significant differences among the two groups as to who they would vote for in the coming election. We extend this example to the problem of modelling the likely electoral responses of agents in the context of the climate change debate, and discuss the notion of interference between related questions that might be asked of an agent in a social simulation that was intended to simulate their likely responses. A modelling technology which could account for such strong social contextual effects would benefit regulatory bodies which need to navigate between multiple interests and concerns, and we shall present one viable avenue for constructing such a technology. A geometric approach will be presented, where the internal state of an agent is represented in a vector space, and their social context is naturally modelled as a set of basis states that are chosen with reference to the problem space.

  8. D. Galea, P. Bruza, K. Kitto, D. Nelson, C. McEvoy, (2011). Modelling the activation of words in human memory: The Spreading Activation, Spooky-action-at-a-distance and the entanglement models compared. Quantum Interaction 5th International Symposium, QI 2011, Aberdeen, UK, June 26-29, 2011, Revised Selected Papers, Eds. D. Song, M. Melucci, et al. LNCS vol. 7052, pp 149-160, Springer.

    Modeling how a word is activated in human memory is an important feature for determining the probability of recall of a word in an extra-list cueing experiment. The spreading activation, spooky-action-at-a-distance and entanglement models have been used to model the activation of a word. Recently a hypothesis was put forward where the mean activation levels of the respective models are as follows: Spreading-activation ≤ Entanglement ≤ Spooky-action-at-a-distance. This article investigates this hypothesis by means of a substantial empirical analysis of each model using the University of South Florida word association, rhyme and word fragment norms.

  9. S. Aerts, K. Kitto, L. Sitbon, (2011). Similarity metrics within a point of view. Quantum Interaction 5th International Symposium, QI 2011, Aberdeen, UK, June 26-29, 2011, Revised Selected Papers, Eds. D. Song, M. Melucci, et al. LNCS vol. 7052, pp 13-24, Springer.

    Vector space based approaches to natural language processing are contrasted with human similarity judgements to show the manner in which human subjects fail to produce data which satisfies all requirements for a metric space. This result would constrains the validity and applicability vector space based (and hence also quantum inspired) approaches to the modelling of cognitive processes. This paper proposes a resolution to this problem, by arguing that pairs of words imply a context which in turn induces a point of view, so allowing a subject to estimate semantic similarity. Context is here introduced as a point of view vector (POVV) and the expected similarity is derived as a measure over the POVV's. Different pairs of words will invoke different contexts and different POVV's. We illustrate the proposal on a few triples of words and outline further research.

  10. K. Kitto, B. Ramm, L. Sitbon, P.D. Bruza, (2011). Quantum theory beyond the physical: information in context. Axiomathes, Volume 21, Number 2, 331-345, DOI: 10.1007/s10516-010-9144-6 .

    Measures and theories of information abound, but there are few formalised methods for treating the contextuality that can manifest in different information systems. Quantum theory provides one possible formalism for treating information in context. This paper introduces a quantum-like model of the human mental lexicon, and shows one set of recent experimental data suggesting that concept combinations can indeed behave non-separably. There is some reason to believe that the human mental lexicon displays entanglement.

  11. K. Kitto, B. Ramm, P.D. Bruza, L. Sitbon, (2010). Testing for the non-separability of ambiguous compounds. Proceedings of the AAAI Fall Symposium on Quantum Informatics for Cognitive, Social, and Semantic Processes (QI 2010). (Definitive version here.)

    Separability is a concept that is very difficult to define, and yet much of our scientific method is implicitly based upon the assumption that systems can sensibly be reduced to a set of interacting components. This paper examines the notion of separability in the creation of bi-ambiguous compounds that is based upon the CHSH and CH inequalities. It reports results of an experiment showing that violations of the CHSH and CH inequality can occur in human conceptual combination.

  12. P. D. Bruza, A. Iqbal and K. Kitto (2010). The role of non-factorizability in determining "pseudo-classical" non-separability. Proceedings of the AAAI Fall Symposium on Quantum Informatics for Cognitive, Social, and Semantic Processes (QI 2010). (Definitive version here.)

    This article introduces a "pseudo classical" notion of modelling non-separability of phenomena. This form of non-separability can viewed as lying between separability and quantum-like non-separability. Non-separability is formalized in terms of the non-factorizabilty of the underlying joint probability distribution. A decision criterium for determining the non-factorizability of the joint distribution is related to determining the rank of a matrix as well as another approach based on the chi-square-goodness-of-fit test. This pseudo-classical notion of non-separability is discussed in terms of quantum games and concept combinations in human cognition.

  13. K. Kitto, P.D. Bruza, (2010) Meaning in context. European Conference on Complex Systems 2010, Satellite meeting Modelling the nonseparability of a very complex world, Lisbon, Portugal.

    Language exhibits a number of contextuality and non-separability effects. This paper reviews a new set of models showing promise for capturing this complexity which are based upon a quantum-like approach.

  14. K. Kitto, (2009). Science and Subjectivity Literary Paritantra (Systems), 1(3&4):18-28.

    Science has been under attack in the last thirty years, and recently a number of prominent scientists have been busy fighting back. Here, an argument is presented that the `science wars' stem from an unreasonably strict adherence to the reductive method on the part of science, but that weakening this stance need not imply a lapse into subjectivity. One possible method for formalising the description of non-separable, contextually dependent complex systems is presented. This is based upon a quantum-like approach.

  15. P.D. Bruza, K. Kitto, D. Nelson and C. McEvoy, (2009). Is there something quantum-like about the human mental lexicon?, Journal of Mathematical Psychology, 53 362-377, doi:10.1016/j.jmp.2009.04.004.
    The link above goes to the definitive version of this paper, but you can access an old preprint of it here.

    Following an early claim by Nelson & McEvoy suggesting that word associations can display `spooky action at a distance behaviour', a serious investigation of the potentially quantum nature of such associations is currently underway. In this paper quantum theory is proposed as a framework suitable for modelling the mental lexicon, specifically the results obtained from both intralist and extralist word association experiments. Some initial models exploring this hypothesis are discussed, and they appear to be capable of substantial agreement with pre-existing experimental data. The paper concludes with a discussion of some experiments that will be performed in order to test these models.

  16. K. Kitto, P.D. Bruza and L. Sitbon, (2009). Generalising Unitary Time Evolution, Proceedings of the Third Quantum Interaction Symposium, Eds. P. Bruza et al. LNAI vol. 5494, pp. 17-28, Springer.

    In this third Quantum Interaction (QI) meeting it is time to examine our failures. One of the weakest elements of QI as a field, arises in its continuing lack of models displaying proper evolutionary dynamics. This paper presents an overview of the modern generalised approach to the derivation of time evolution equations in physics, showing how the notion of symmetry is essential to the extraction of operators in quantum theory. The form that symmetry might take in non-physical models is explored, with a number of viable avenues identified.

  17. P.D. Bruza, K. Kitto, D. Nelson and C. McEvoy, (2009). Extracting spooky-activation-at-a-distance from considerations of entanglement, Proceedings of the third Quantum Interaction symposium. Eds. P. Bruza et al. LNAI vol. 5494, pp. 71-83, Springer.

    Following an early claim by Nelson & McEvoy suggesting that word associations can display `spooky action at a distance behaviour', a serious investigation of the potentially quantum nature of such associations is currently underway. This paper presents a simple quantum model of a word association system. It is shown that a quantum model of word entanglement can recover aspects of both the Spreading Activation model and the Spooky model of word association experiments.

  18. C. Flender, K. Kitto and P. Bruza, (2009). Nonseparability of Shared Intentionality, Proceedings of the third Quantum Interaction symposium. Eds. P. Bruza et al. LNAI vol. 5494, pp. 211-224, Springer.

    According to recent studies in developmental psychology and neuroscience, symbolic language is essentially intersubjective. Empathetically relating to others renders possible the acquisition of linguistic constructs. Intersubjectivity develops in early ontogentic life when interactions between mother and infant mutually shape their relatedness. Empirical findings suggest that the shared attention and intention involved in those interactions is sustained as it becomes internalized and embodied. Symbolic language is derivative and emerges from shared intentionality. In this paper, we present a formalization of shared intentionality based upon a quantum approach. From a phenomenological viewpoint, we investigate the nonseparable, dynamic and sustainable nature of social cognition and evaluate the appropriateness of quantum interaction for modelling intersubjectivity.

  19. C. Flender, K. Kitto and P. Bruza, (2009). Beyond Ontology in Information Systems, Proceedings of the third Quantum Interaction symposium. Eds. P. Bruza et al. LNAI vol. 5494, pp. 289-298, Springer.

    Information systems are socio-technical systems. Their design, analysis and implementation requires appropriate languages for representing social and technical concepts. However, many symbolic modelling approaches fall into the trap of underemphasizing social aspects of information systems. This often leads to an inability of ontological models to incorporate effects such as contextual dependence and emergence. Moreover, as designers take the perspective of people living with and alongside the information system to be modelled social interaction becomes a primary concern. Ontologies are too prescriptive and do not account properly for social concepts. Based on State-Context-Property (SCoP) systems we propose a quantum-inspired approach for modelling information systems.

  20.  K. Kitto, (2008). High End Complexity, International Journal of General Systems, Volume 37, Issue 6, pp 689-714, doi:10.1080/03081070701524232.
    The link above goes to the definitive version of this paper, but you can access an old preprint of it here.

    Despite the general recognition of complexity as an important concept and decades of work, very little progress has been made in the attempt to define complexity. It is suggested that this is due to the fact that the definition of complex behaviour is itself complex, forming a scale from the simple to the more and more complex. Those systems at the high end of the scale are not at present well modelled, and reasons why this might be the case are presented. The possibility that quantum theories may be able to model such high end complexity is investigated.

  21. K. Kitto, (2008). Why Quantum Theory?, Proceedings of the Second Quantum Interaction Symposium, pp. 11-18, College Publications.

    This article investigates one of the fundamental issues confronting a field that investigates quantum interaction; namely why is it necessary? The need to investigate an interaction using a quantum formalism is argued to arise when the system under study is sufficiently complex. In particular, if the system is displaying contextual behaviour then a quantum approach often incorporates this behaviour very naturally. Thus, a way in which much of the disparte work in the field of quantum interaction can be both justified to the broader community and eventually unified is presented. The nature of contextual behaviour and its relationship to nonlocality is explored.

  22. P. D. Bruza, K. Kitto, D. Nelson and C. McEvoy, (2008). Entangling Words and Meaning, Proceedings of the Second Quantum Interaction Symposium, pp. 118-124, College Publications.

    Human memory experiments appear to be generating "nonlocal" effects. In this paper the possibility that words might be entangled in human semantic space is seriously entertained. This approach leads to a very natural picture of the way in which context might affect word association via the standard interpretation of quantum measurement. Two possible scenarios for testing such a hypothesis are suggested, both based upon potential violations of the CHSH inequality.

  23. K. Kitto, (2007). Process Physics: quantum theories as models of complexity, Invited paper for the Electronic Journal of Theoretical Physics Special Issue on the Physics of Emergence and Organization, Volume 4, Issue 16 I.
    Published: (2008) Physics of Emergence and Organization, pp77-108, Eds. I. Licata, A. J. Sakaji, World Scientific.

    Originally based upon a pregeometric model of the Universe, Process Physics has now been formulated as far more general modelling paradigm that is capable of generating complex emergent behaviour. This article discusses the original relational model of Process Physics and the emergent hierarchical structure that it generates, linking the reason for this emergence to the historical basis of the model in quantum field theory. This historical connection is used to motivate a new interpretation of the general class of quantum theories as providing models of certain aspects of complex behaviour. A summary of this new realistic interpretation of quantum theory is presented and some applications of this viewpoint to the description of complex emergent behaviour are sketched out.

  24. K. Kitto, (2005). Gauging ALife: Emerging Complex Systems, in Recent Advances in Artificial Life. Advances in Natural Computation vol. 3, pp117-130, Eds. H.A. Abbas, et al. Singapore: World Scientific.

    Despite its early successes, ALife has not tended to live up to its original promise, with any emergent behaviour very rarely manifesting itself in such a way that new higher level emergence can occur. This problem has been recognised in two related concepts; the failure of ALife simulations to display Open Ended Evolution, and their inability to dynamically generate more than two hierarchical levels of behaviour. This paper will suggest that these problems of ALife stem from a missing sense of contextuality in the models of ALife. A number of theories which exhibit some form of contextual dependence will be discussed, in particular, the gauge theories of quantum field theory.

  25. Cahill, R. T. and K. Kitto, (2003). Michelson-Morley Experiments Revisited and the Cosmic Background Radiation Preferred Frame , Aperion 10:104-117.

    The Michelson-Morley interferometer experiments were designed to measure the speed of the Earth through the aether. The results were always believed to have been null - no effect. This outcome formed the basis for Einstein's Special and General Relativity formalism. The new process physics shows that absolute motion, now understood to be relative to the quantum foam that is space, is observable, but only if the interferometer operates in gas mode. A re-analysis here shows that the results from the gas-mode interferometers were not null, but in fact large when re-analysed to take account of the effect of the air, or helium, in which the apparatus operated. The speed of absolute motion is comparable to that determined from the Cosmic Background Radiation anisotropy, but the direction is not revealed. So absolute motion is meaningful and measureable, thus refuting Einstein's assumption. This discovery shows that a major re-assessment of the interpretation of the Special and General Relativity formalism is called for, a task already provided by Process Physics. This new information-theoretic physics makes it clear that Michelson-Morley type experiments are detecting motion through the quantum foam, which is space. Hence we see direct evidence of quantum gravity effects, as predicted by Process Physics

  26. K, Kitto, (2002). Dynamical Hierarchies in Fundamental Physics, in Workshop Proceedings of the 8th International Conference on the Simulation and Synthesis of Living Systems (ALife VIII), pp55-62, Eds. E. Bilotta et al. Sydney: Univ. New South Wales.

    A new process orientated physics is being developed at Flinders University. These ideas were initially motivated by deep unsolved problems in fundamental physics, such as the difficulty of quantizing gravity, the missing arrow of time, the question of how to interpret quantum mechanics, and perhaps most importantly, a problem with the very methodology of our fundamental descriptions of the Universe. A proposed solution to these problems, Process Physics, has led to what can be viewed as a hierarchical model of reality featuring a Universe that exhibits behaviour very reminiscent of living systems.

  27. R.T. Cahill, C.M. Klinger and K. Kitto, (2000). Process Physics: Modelling Reality as Self-Organising Information arXiv:gr-qc/0009023v1, The Physicist, 37(6), 191-195.

    The new Process Physics models reality as self-organising relational information and takes account of the limitations of logic, discovered by Godel and extended by Chaitin, by using the concept of self-referential noise. Space and quantum physics are emergent and unified, and described by a Quantum Homotopic Field Theory of fractal topological defects embedded in a three-dimensional fractal process-space.

    PhD thesis

    Modelling and generating complex emergent behaviour
    PhD Awarded December 2006

    Despite a general recognition of the importance of complex systems, there is a dearth of general models capable of describing their dynamics. This is attributed to a complexity scale; the models are attempting to describe systems at different parts of the scale and are hence not compatible. We require new models capable of describing complex behaviour at different points of the complexity scale. This work identifies, and proceeds to examine systems at the high end of the complexity scale, those which have not to date been well understood by our current modelling methodology. It is shown that many such models exhibit what might be termed contextual dependency, and that it is precisely this feature which is not well understood by our current modelling methodology. A particular problem is discussed; our apparent inability to generate systems which display high end complexity, exhibited by for example the general failure of strong ALife. A new model, Process Physics, that has been developed at Flinders University is discussed, and arguments are presented that it exhibits high end complexity. The features of this model that lead to its displaying such behaviour are discussed, and the generalisation of this model to a broader range of complex systems is attempted.
    Themes: contextuality and complexity; reductive failure; Process Physics; quantum theories as models of complexity

    You can download a copy of its frontmatter, or if you like, the entire manuscript.