11 research outputs found

    Temporal structure of neural oscillations underlying sensorimotor coordination: a theoretical approach with evolutionary robotics

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    The temporal structure of neural oscillations has become a widespread hypothetical \mechanism" to explain how neurodynamics give rise to neural functions. Despite the great number of empirical experiments in neuroscience and mathematical and computa- tional modelling investigating the temporal structure of the oscillations, there are still few systematic studies proposing dynamical explanations of how it operates within closed sensorimotor loops of agents performing minimally cognitive behaviours. In this thesis we explore this problem by developing and analysing theoretical models of evolutionary robotics controlled by oscillatory networks. The results obtained suggest that: i) the in- formational content in an oscillatory network about the sensorimotor dynamics is equally distributed throughout the entire range of phase relations; neither synchronous nor desyn- chronous oscillations carries a privileged status in terms of informational content in relation to an agent's sensorimotor activity; ii) although the phase relations of oscillations with a narrow frequency difference carry a relatively higher causal relevance than the rest of the phase relations to sensorimotor coordinations, overall there is no privileged functional causal contribution to either synchronous or desynchronous oscillations; and iii) oscilla- tory regimes underlying functional behaviours (e.g. phototaxis, categorical perception) are generated and sustained by the agent's sensorimotor loop dynamics, they depend not only on the dynamic structure of a sensory input but also on the coordinated coupling of the agent's motor-sensory dynamics. This thesis also contributes to the Coordination Dynam- ics framework (Kelso, 1995) by analysing the dynamics of the HKB (Haken-Kelso-Bunz) equation within a closed sensorimotor loop and by discussing the theoretical implications of such an analysis. Besides, it contributes to the ongoing philosophical debate about whether actions are either causally relevant or a constituent of cognitive functionalities by bringing this debate to the context of oscillatory neurodynamics and by illustrating the constitutive notion of actions to cognition

    Behavior control in the sensorimotor loop with short-term synaptic dynamics induced by self-regulating neurons

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    The behavior and skills of living systems depend on the distributed control provided by specialized and highly recurrent neural networks. Learning and memory in these systems is mediated by a set of adaptation mechanisms, known collectively as neuronal plasticity. Translating principles of recurrent neural control and plasticity to artificial agents has seen major strides, but is usually hampered by the complex interactions between the agent's body and its environment. One of the important standing issues is for the agent to support multiple stable states of behavior, so that its behavioral repertoire matches the requirements imposed by these interactions. The agent also must have the capacity to switch between these states in time scales that are comparable to those by which sensory stimulation varies. Achieving this requires a mechanism of short-term memory that allows the neurocontroller to keep track of the recent history of its input, which finds its biological counterpart in short-term synaptic plasticity. This issue is approached here by deriving synaptic dynamics in recurrent neural networks. Neurons are introduced as self-regulating units with a rich repertoire of dynamics. They exhibit homeostatic properties for certain parameter domains, which result in a set of stable states and the required short-term memory. They can also operate as oscillators, which allow them to surpass the level of activity imposed by their homeostatic operation conditions. Neural systems endowed with the derived synaptic dynamics can be utilized for the neural behavior control of autonomous mobile agents. The resulting behavior depends also on the underlying network structure, which is either engineered or developed by evolutionary techniques. The effectiveness of these self-regulating units is demonstrated by controlling locomotion of a hexapod with 18 degrees of freedom, and obstacle-avoidance of a wheel-driven robot. © 2014 Toutounji and Pasemann

    Modes of production, metabolism and resilience: toward a framework for the analysis of complex social-ecological systems

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    The field of environmental sociology has undergone drastic change in recent decades, in context of a broader reconfiguration of the terrain of sociological theory and practice. Systems-based approaches to the study of human society, located at the interface between the natural and social sciences have since yielded to a fragmentary body of theory and practice. Subsequent developments such as the emergence of actor network theory, linguistic constructivism and epistemic relativism, have sought not only to question the status of scientific discourse as immutable authority, but also the legitimacies of positivism and macro-theoretical modeling as tenable research programs. This thesis suggests that much of this critique is misdirected, informed as it is by false dichotomies of theory and method which empahsise the separatism of the social, and the difficulty of normative analysis. Over the past twenty years, sociologists have begun to re-engage with systemic theory, albeit with a plethora of new anti-reductionist informants rooted in epistemologies of emergentism, complexity and critical realism. Parallel developments in Marxian ecological thought and human ecology offer further conceptual complementarities and points of dialogue, with which to develop new methodologies for the study of human collectives as ‗social-ecological systems‘. The objectives of this work are thus twofold; (1) to advance an alternative basis for theory and practice in environmental sociology, drawing upon the informants of complexity theory, resilience-based human ecology, and Marx‘s concepts of mode of production and metabolic rift; (2) to contribute to this largely theoretical body of knowledge, by operationalising the preceding informants within a specific case study; that of communal farming, or the 'rundale system‘, in nineteenth century Ireland. The ecological dynamics of the rundale system are thus explored through the imposition of a range of quantitative, archival and comparative methods, as an exercise in the explanatory capacities of the investigative framework developed throughout this work. This methodology rejects existing explanatory models which emphasise the role of 'prime movers‘ in the generation of differential ecological outcomes, toward an account which emphasises both macro-structural complexity, and the augmentation of adaptive capacity from below

    Using MapReduce Streaming for Distributed Life Simulation on the Cloud

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    Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

    African Handbook of Climate Change Adaptation

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    This open access book discusses current thinking and presents the main issues and challenges associated with climate change in Africa. It introduces evidences from studies and projects which show how climate change adaptation is being - and may continue to be successfully implemented in African countries. Thanks to its scope and wide range of themes surrounding climate change, the ambition is that this book will be a lead publication on the topic, which may be regularly updated and hence capture further works. Climate change is a major global challenge. However, some geographical regions are more severly affected than others. One of these regions is the African continent. Due to a combination of unfavourable socio-economic and meteorological conditions, African countries are particularly vulnerable to climate change and its impacts. The recently released IPCC special report "Global Warming of 1.5º C" outlines the fact that keeping global warming by the level of 1.5º C is possible, but also suggested that an increase by 2º C could lead to crises with crops (agriculture fed by rain could drop by 50% in some African countries by 2020) and livestock production, could damage water supplies and pose an additonal threat to coastal areas. The 5th Assessment Report produced by IPCC predicts that wheat may disappear from Africa by 2080, and that maize— a staple—will fall significantly in southern Africa. Also, arid and semi-arid lands are likely to increase by up to 8%, with severe ramifications for livelihoods, poverty eradication and meeting the SDGs. Pursuing appropriate adaptation strategies is thus vital, in order to address the current and future challenges posed by a changing climate. It is against this background that the "African Handbook of Climate Change Adaptation" is being published. It contains papers prepared by scholars, representatives from social movements, practitioners and members of governmental agencies, undertaking research and/or executing climate change projects in Africa, and working with communities across the African continent. Encompassing over 100 contribtions from across Africa, it is the most comprehensive publication on climate change adaptation in Africa ever produced

    Social context of creativity

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    This thesis analyses the long-distance control of the environmentally-situated imagination, in both spatial and temporal dimensions. Central to the project is what I call the extended social brain hypothesis. Grounded in the Peircean conception of 'pragmaticism‘, this re-introduces technical intelligence to Dunbar‘s social brain—conceptually, through Clark‘s 'extended mind‘ philosophy, and materially, through Callon‘s 'actor–network theory‘. I claim that: There is no subjectivity without intersubjectivity. That is to say: as an evolutionary matter, it was necessary for the empathic capacities to evolve before the sense of self we identify as human could emerge. Intersubjectivity is critical to human communication, because of its role in interpreting intention. While the idea that human communication requires three levels of intentionality carries analytical weight, I argue that the inflationary trajectory is wrong as an evolutionary matter. The trend is instead towards increasing powers of individuation. The capacity for tool-use is emphasized less under the social brain hypothesis, but the importance of digital manipulation needs to be reasserted as part of a mature ontology. These claims are modulated to substantiate the work-maker, a socially situated (and embodied) creative agent who draws together Peircean notions of epistemology, phenomenology and oral performance

    Handbook of Well-Being

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    It is a pleasure to bring to you the eHandbook of Subjective Well-Being, the science of when and why people experience and evaluate their lives in positive ways, including aspects such as positive feelings, life satisfaction, and optimism. There are chapters in this eHandbook on the philosophy and history of well-being, as well as reviews of empirical research on the ways to assess well-being, the circumstances that predict it, the outcomes that it produces, the societal policies that enhance it, and many other social, biological, and cultural processes that help us understand why some people are happy and satisfied with their lives, while others are not. There are also chapters on theories of well-being, such as the baseline or set-point models. We believe that Open publication is the wave of the future (Jhangiani & Biswas-Diener, 2017). Therefore, we are presenting the handbook in an electronic format so that it is widely available to everyone around the world. The handbook is entirely open and free – anyone can read and use it without cost. This is important to us as we desire to lower knowledge barriers for individuals and communities, especially because it provides access to students, educators, and scholars who do not have substantial financial resources. We are not certain if this is the first free and open handbook in the behavioral sciences, but hopefully it will not be the last. In the past the prohibitive price of many handbooks have made them available only to scholars or institutions in wealthy nations, and this is unfortunate. We believe scientific scholarship should be available to all. The field of subjective well-being has grown at rapid pace over the last several decades, and many discoveries have been made. When Ed Diener began his research within the field in 1981 there were about 130 studies published that year on the topic, as shown using a Google Scholar search on “subjective well-being.” Eighteen years later when Shigehiro Oishi earned his Ph.D. in 2000 there were 1,640 publications that year on the topic, and when Louis Tay was awarded a Ph.D. in 2011 there were 10,400 publications about subjective well-being. Finally, in 2016 there were 18,300 publications – in that single year alone! In other words, during the time that Diener has been studying the topic, scholarship on subjective well-being has grown over 100-fold! It is not merely the number of published studies that has grown, but there have been enormous leaps forward in our understanding. In the 1980s, there were questions about the reliability and validity of subjective well-being assessments, and the components that underlie it. One notable advance is our understanding and measurement of well-being. We now know a great deal about the validity of self-report measures, as well as the core evaluative and affective components that make up subjective well-being. Further, scholars have a much greater understanding of the processes by which people report their subjective well-being, and various biases or artifacts that may influence these reports. In 1982 many studies were focused on demographic factors such as income, sex, and age that were correlated with subjective well-being. By 2016 we understood much more about temperament and other internal factors that influence happiness, as well as some of the outcomes in behavior that subjective well-being helps produce (e.g., income, performance, physical health, longevity). In the 1980s, researchers assumed that people adapt to almost any life event, and that different life events only have a short-term effect on subjective well-being. A number of large-scale longitudinal studies later showed that that is not the case. By now we know what kinds of life events affect our subjective well-being, how much, and for roughly how long. In the 1980s researchers believed that economic growth would not increase the happiness of a given nation. Now we know when economic growth tends to increase the happiness of a given nation. Additionally, we know much more about the biology of subjective well-being, and an enormous amount more about culture and well-being, a field that was almost nonexistent in 1982. With the advent of positive psychology, we are also beginning to examine practices and interventions that can raise subjective well-being. Given the broad interest in subjective well-being in multiple fields like psychology, economics, political science, and sociology, there have been important developments made toward understanding how societies differ in well-being. This understanding led to the development of national accounts of well-being – societies using well-being measures to help inform policy deliberations. This advance changes the focus of governments away from a narrow emphasis on economic development to a broader view which sees government policies as designed to raise human well-being. We were fortunate to have so many leading scholars of subjective well-being and related topics contribute to this volume. We might be slightly biased but most of the chapters in this eHandbook are truly superb. Not only do they provide a broad coverage of a large number of areas, but many of the chapters present new ways of thinking about these areas. Below is a brief overview of each of the sections in this volume: In Section 1 we begin the volume with chapters on philosophical, historical, and religious thinking on well-being through the ages. Next, we cover the methods and measures used in the scientific study of well-being. Section 2 is devoted to theories of well-being such as the top-down theory, activity theory, goal theory, self-determination theory, and evolutionary theory. Section 3 covers the personality, genetics, hormones, and neuroscience of well-being. Then, demographic factors such as age, gender, race, religion, and marital status are discussed. Section 4 is devoted to how domains of life – such as work, finance, close relationships, and leisure – are related to overall subjective well-being. Section 5 covers the various outcomes of subjective well-being, ranging from work outcomes, to cognitive outcomes, to health, and finally relationship outcomes. Section 6 covers interventions to increase subjective well-being. Finally, Section 7 is devoted to cultural, geographical, and historical variations in subjective well-being. This eHandbook presents the most up-to-date and comprehensive understanding of subjective well-being – and it is freely available to all! The editors would like to extend their thanks to several individuals who have been critical to the success of the handbook. First, our gratitude is immense toward Chris Wiese, Keya Biswas-Diener, and Danielle Geerling, who organized and kept the entire venture on track. Their hard work and organizational skills were wonderful, and the book would not have been possible without them. Second, we extend our thanks to the Diener Education Fund, a charitable organization devoted to education that in part made this project possible. In particular we express deep gratitude to Mary Alice and Frank Diener. Not only did their help make this eHandbook possible, but their lives stood as shining examples of the way to pursue well-being!https://digitalcommons.unomaha.edu/psychfacbooks/1008/thumbnail.jp

    Ambivalent Sovereignty: Inquiries into the Dual Foundation of Political Realism\u27s Subject

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    Ambivalent Sovereignty inquires into the subject of political realism. This subject, sovereign authority, appears to have a dual foundation. It appears divided against itself, but how can realism nonetheless observe legitimate modes of sovereignty emerge? Against the liberal idea that a synthesis of both material-coercive and ideal-persuasive powers should be accomplished, within the world of international relations, realism gives meaning to a structural type of state power that is also constitutionally and legitimately dividing itself--against itself. Machiavelli but particularly also other realists such as Hannah Arendt, Max Weber, and Aristotle are being reinterpreted to demonstrate why each state\u27s ultimate authority may symbiotically emerge from its self-divisions, rather than from one synthetic unity. Whereas liberal theorists, from Montesquieu to John Rawls and Alexander Wendt, err too far in assuming the presence of the state\u27s monistic authority, the realist theorists further advance an answer to how sovereign states may begin to both recognize and include only the most-legitimate manifestations of their common dualist authority. Ambivalent Sovereignty is relevant in this sense as it transcends-and-yet-includes these common dualities: freedom/necessity; emergence/causation; self-organization/power structures
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