| 1. |
- Anselm, Jonas, et al.
(författare)
-
Bannlys alla politiska beslut som ger mer klimatutsläpp
- 2014
-
Ingår i: Dagens Nyheter.
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Torftig valdebatt. Dagspolitiken klarar inte att hantera ödesfrågan om klimatet, vilket oroar oss. Vi föreslår därför ett ”utsläppsmoratorium”: inga beslut får tas som ökar utsläppen av växthusgaser. Principen måste kopplas till mål om exempelvis förnybar energi och grön infrastruktur, skriver 23 forskare och debattörer.
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| 2. |
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| 3. |
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| 4. |
- Drets, G. A., et al.
(författare)
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Fingerprint Sub-Classification : A Neural Network Approach
- 2022
-
Ingår i: Intelligent Biometric Techniques in Fingerprint and Face Recognition. - Boca Raton : Informa UK Limited. ; , s. 106-134
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The modern era in fingerprint identification began at the end of last century, with Sir Francis Galton and Juan Vucetich, and at the beginning of the present century with Sir Edward Henry. Fingerprints are commonly associated with law enforcement applications, like criminal identification, but recently their application has been extended to more popular areas, such as access control, driver license applications, and bank transactions. Due to the great variety of fingerprint patterns, the application of Henry’s definitions of core and delta, stated previously, is not straightforward. The FBI proposes more specialized rules for locating the SPs in different archetypes of fingerprints. Human fingerprints are the most widespread mean of person identification. The use of fingerprints in law enforcement applications deals with large databases, so classification aids to narrow the search space for further matching stage. The process of counting ridges between singular points core and delta is the basis for fingerprint subclassification.
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| 5. |
- Eckerberg, Katarina, et al.
(författare)
-
Varför brister politikerna när det gäller miljömålen?
- 2012
-
Ingår i: Dagens Nyheter. - 1101-2447.
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Vad ska vi svara? Politikernas ambitiösa miljömål uppfylls sällan eller aldrig. När våra elever frågar oss varför blir vi ofta svaret skyldiga. Om politikerna inte vill att väljarna ska dra slutsatsen att de har misslyckats, måste de ange en realistisk väg att nå de uppsatta målen. Det skulle väcka respekt, skriver ledande forskare och samhällsplanerare.
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| 6. |
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| 7. |
- Ekenberg, Love, et al.
(författare)
-
Deliberation, representation, equity : research approaches, tools and algorithms for participatory processes
- 2017
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- What can we learn about the development of public interaction in e-democracy from a drama delivered by mobile headphones to an audience standing around a shopping center in a Stockholm suburb? In democratic societies there is widespread acknowledgment of the need to incorporate citizens' input in decision-making processes in more or less structured ways. But participatory decision making is balancing on the borders of inclusion, structure, precision and accuracy. To simply enable more participation will not yield enhanced democracy, and there is a clear need for more elaborated elicitation and decision analytical tools. This rigorous and thought-provoking volume draws on a stimulating variety of international case studies, from flood risk management in the Red River Delta of Vietnam, to the consideration of alternatives to gold mining in Ro?ia Montana in Transylvania, to the application of multi-criteria decision analysis in evaluating the impact of e-learning opportunities at Uganda's Makerere University. Editors Love Ekenberg (senior research scholar, International Institute for Applied Systems Analysis [IIASA], Laxenburg, professor of Computer and Systems Sciences, Stockholm University), Karin Hansson (artist and research fellow, Department of Computer and Systems Sciences, Stockholm University), Mats Danielson (vice president and professor of Computer and Systems Sciences, Stockholm University, affiliate researcher, IIASA) and Göran Cars (professor of Societal Planning and Environment, Royal Institute of Technology, Stockholm) draw innovative collaborations between mathematics, social science, and the arts. They develop new problem formulations and solutions, with the aim of carrying decisions from agenda setting and problem awareness through to feasible courses of action by setting objectives, alternative generation, consequence assessments, and trade-off clarifications. As a result, this book is important new reading for decision makers in government, public administration and urban planning, as well as students and researchers in the fields of participatory democracy, urban planning, social policy, communication design, participatory art, decision theory, risk analysis and computer and systems sciences.
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| 8. |
- Hammerstein, Peter, 1971-
(författare)
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Stochastic Resonance and Noise-Assisted Signal Transfer : On Coupling Effects of Stochastic Resonators and Spectral Optimization of Fluctuations in Random Network Switches
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Recent research shows that noise or random fluctuations must not always be destructive in Nature by degrading system performance. On the contrary, in nonlinear systems they can synchronize systems or enhance the quality of signal transmission. The latter possibility is reported in the thesis.The phenomenon of stochastic resonance (SR) is presented and illustrated by an example of a ferromagnetically coupled spin chain, described by the Glauber's stochastic Ising spin model. It is demonstrated that an optimal strength of the next-neighbor interaction is able to improve the SR-effect. A similar mechanism has further been studied on the stochastic nonlinear dynamics of a ferromagnetic stripe domain in an inhomogeneous thin film. SR and its dependence on the domain stiffness, which is due to the exchange interaction, are presented. Experimental parameters for potential verification on Bi-doped epitaxial garnet-ferrite films are proposed. Further-on, a nonlinear model of a junction in neuronal and road structures is studied using various types of noise (stochastic processes) to generate the incoming traffic. It is shown that random fluctuations are able to enhance signal transmission, whereby the zero crossings of colored (1/fk) Gaussian noise is superior to Poissonian noise and, in certain cases, to deterministic, periodic traffic too. Optimal traffic for k ≈ 1 has been found. In case of Gaussian 1/fk noise modulated periodic input, noise-assisted traffic can be observed as well and demonstrate how random fluctuations can enhance the signal traffic efficiency in a network. The effect of an optimal k has finally been applied to a data package network switch, whereby a stochastic data scheduling algorithm is proposed and investigated numerically and analytically.
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| 9. |
- Hassannejad, Nazir Azadeh, et al.
(författare)
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A Cortical Network Model for Cognitive and Emotional Influences in Human Decision Making.
- 2015
-
Ingår i: BioSystems. - : Elsevier BV. - 0303-2647 .- 1872-8324. ; 136, s. 128-141
-
Tidskriftsartikel (refereegranskat)abstract
- Decision making (DM)[1] is a complex process that appears to involve several brain structures. In particular, amygdala, orbitofrontal cortex (OFC) and lateral prefrontal cortex (LPFC) seem to be essential in human decision making, where both emotional and cognitive aspects are taken into account. In this paper, we present a computational network model representing the neural information processing of DM, from perception to behavior. We model the population dynamics of the three neural structures (amygdala, OFC and LPFC), as well as their interaction. In our model, the neurodynamic activity of amygdala and OFC represents the neural correlates of secondary emotion, while the activity of certain neural populations in OFC alone, represent the outcome expectancy of different options. The cognitive/rational aspect of DM is associated with LPFC. Our model is intended to give insights on the emotional and cognitive processes involved in DM under various internal and external contexts. Different options for actions are represented by the oscillatory activity of cell assemblies, which may change due to experience and learning. Knowledge and experience of the outcome of our decisions and actions can eventually result in changes in our neural structures, attitudes and behaviors. Simulation results may have implications for how we make decisions for our individual actions, as well as for societal choices, where we take examples from transport and its impact on CO2 emissions and climate change. [1] Decision making is abbreviated as DM throughout the text
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| 10. |
- Hassannejad Nazir, Azadeh, et al.
(författare)
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Computational modeling of attractor-based neural processes involved in the preparation of voluntary actions
- 2023
-
Ingår i: Cognitive Neurodynamics. - : Springer Nature. - 1871-4080 .- 1871-4099.
-
Tidskriftsartikel (refereegranskat)abstract
- Volition is conceived as a set of orchestrated executive functions, which can be characterized by features, such as reason-based and goal-directedness, driven by endogenous signals. The lateral prefrontal cortex (LPFC) has long been considered to be responsible for cognitive control and executive function, and its neurodynamics appears to be central to goal-directed cognition. In order to address both associative processes (i.e. reason-action and action-outcome) based on internal stimuli, it seems essential to consider the interconnectivity of LPFC and the anterior cingulate cortex (ACC). The critical placement of ACC as a hub mediates projection of afferent expectancy signals directly from brain structures associated with emotion, as well as internal signals from subcortical areas to the LPFC. Apparently, the two cortical areas LPFC and ACC play a pivotal role in the formation of voluntary behaviors. In this paper, we model the neurodynamics of these two neural structures and their interactions related to intentional control. We predict that the emergence of intention is the result of both feedback-based and competitive mechanisms among neural attractors. These mechanisms alter the dimensionalities of coexisting chaotic attractors to more stable, low dimensional manifolds as limit cycle attractors, which may result in the onset of a readiness potential (RP) in SMA, associated with a decision to act.
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| 11. |
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| 12. |
- Liljenström, Hans
(författare)
-
A biologically inspired model for pattern recognition
- 2010
-
Ingår i: Journal of Zhejiang University Science B. - 1673-1581 .- 1862-1783. ; 11, s. 115-126
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, a novel bionic model and its performance in pattern recognition are presented and discussed. The model is constructed from a bulb model and a three-layered cortical model, mimicking the main features of the olfactory system. The olfactory bulb and cortex models are connected by feedforward and feedback fibers with distributed delays. The Breast Cancer Wisconsin dataset consisting of data from 683 patients divided into benign and malignant classes is used to demonstrate the capacity of the model to learn and recognize patterns, even when these are deformed versions of the originally learned patterns. The performance of the novel model was compared with three artificial neural networks (ANNs), a back-propagation network, a support vector machine classifier, and a radial basis function classifier. All the ANNs and the olfactory bionic model were tested in a benchmark study of a standard dataset. Experimental results show that the bionic olfactory system model can learn and classify patterns based on a small training set and a few learning trials to reflect biological intelligence to some extent
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| 13. |
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| 14. |
- Liljenström, Hans
(författare)
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Att fatta beslut, av fri vilja
- 2021
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Ingår i: Fri vilja och mänskligt ansvar. - 9789189139602 ; , s. 123-156
-
Bokkapitel (populärvet., debatt m.m.)
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| 15. |
- Liljenström, Hans
(författare)
-
Attention Modulation of Sensory Systems
- 2009
-
Konferensbidrag (refereegranskat)abstract
- Attention and arousal seems to enhance the efficiency of neural information processing. We use computer simulations of various sensory systems in order to investigate how the neurodynamics of these systems can be modulated for optimal performance in an unknown and changing environment. Using an inter-scale model of the insect antennal lobe, we demonstrate how attention modulation can change the sensitivity for sex pheromones. We also study how neural oscillations in mammalian olfactory cortex can serve to amplify weak signals and sustain an input pattern for more accurate information processing, and how chaotic-like behaviour could increase the sensitivity in initial, exploratory states. Finally, we use a neural network model of visual cortex area V4, in order to investigate potential cellular and network mechanisms for visual attention, reproducing experimental findings of attention induced gamma-frequency synchronization
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| 16. |
- Liljenström, Hans, et al.
(författare)
-
Background survey
- 2016
-
Ingår i: Towards a fossil-free society in the Stockhol-Mälar region. - 9789197604840 ; , s. 12-92
-
Bokkapitel (refereegranskat)
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| 17. |
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| 18. |
- Liljenström, Hans
(författare)
-
Connecting urban and regional socio-ecological transitions: Paths to a non fossil society in the Swedish Stockholm-Malar area
- 2017
-
Ingår i: Procedia Engineering. - : Elsevier BV. - 1877-7058. ; 198, s. 1036-1045
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: The embedding of cities in a wider regional frame is central for long term planning regarding the transformation of such parts of society. This holds especially true for urban centers of national or sub national status. In this presentation we are drawing on 4 years of research work and stakeholder consultations in the Swedish part of the EU COMPLEX project dealing with the transition to non fossil societies. In our presentation the regional multi layered governance which encompasses both a large (the Swedish capital) city and its surrounding region with an archipelago of larger and smaller towns is at the heart of the presentation. Our core interest is in the transition to sustainable and resilient urban futures. Especially we are drawing on the experiences from the Swedish case in the EU project COMPLEX.Method: We are relying both on stakeholder consultations with regard to long term planning as well as on specific regional modelling efforts covering specific features as municipality planning, economic regional analysis, land use studies and cognitive analysis regarding decision making by individuals,Results: We have focused on the systemic interactions of many different kinds covering long term developments (up to 2050). Our focus is to analyze features of the transition process of our urban-region at large and the connected decision making features e.g. in terms of scenario elaborations.Discussion: We highlight the differences of opinions among a wide range of stakeholders with regard to their understanding of the issues, their ideological positioning about core matters of concerns and the various positions about appropriate paths for reaching the goals of the transition to a non-fossil urban-super region situation in our chosen case area. (c) 2017 Published by Elsevier Ltd.
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| 19. |
- Liljenström, Hans
(författare)
-
Consciousness, decision making, and volition: freedom beyond chance and necessity
- 2022
-
Ingår i: Theorie in den Biowissenschaften / Theory in Biosciences. - : Springer Science and Business Media LLC. - 1431-7613 .- 1611-7530. ; 141, s. 125-140
-
Tidskriftsartikel (refereegranskat)abstract
- What is the role of consciousness in volition and decision-making? Are our actions fully determined by brain activity preceding our decisions to act, or can consciousness instead affect the brain activity leading to action? This has been much debated in philosophy, but also in science since the famous experiments by Libet in the 1980s, where the current most common interpretation is that conscious free will is an illusion. It seems that the brain knows, up to several seconds in advance what "you" decide to do. These studies have, however, been criticized, and alternative interpretations of the experiments can be given, some of which are discussed in this paper. In an attempt to elucidate the processes involved in decision-making (DM), as an essential part of volition, we have developed a computational model of relevant brain structures and their neurodynamics. While DM is a complex process, we have particularly focused on the amygdala and orbitofrontal cortex (OFC) for its emotional, and the lateral prefrontal cortex (LPFC) for its cognitive aspects. In this paper, we present a stochastic population model representing the neural information processing of DM. Simulation results seem to confirm the notion that if decisions have to be made fast, emotional processes and aspects dominate, while rational processes are more time consuming and may result in a delayed decision. Finally, some limitations of current science and computational modeling will be discussed, hinting at a future development of science, where consciousness and free will may add to chance and necessity as explanation for what happens in the world.
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| 20. |
- Liljenström, Hans, et al.
(författare)
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Decisions and Downward Causation in Neural Systems
- 2016
-
Ingår i: Advances in Cognitive Neurodynamics (V). - Singapore : Springer Singapore. - 9789811002052 ; :5, s. 161-167
-
Bokkapitel (refereegranskat)abstract
- For any complex system, consisting of several organizational levels, the problem of causation is profound. Usually, science considers upward causation as fundamental, paying less or no attention to any downward causation. This is also true for the nervous system, where cortical neurodynamics and higher mental functions are normally considered causally dependent on the nerve cell activity, or even the activity at the ion channel level. This study presents a computational approach to decision making (DM) and downward causation in cortical neural systems. We have developed models of paleo- and neocortical structures, in order to study their mesoscopic neurodynamics, as a link between the microscopic neuronal and macroscopic mental events and processes. We demonstrate how complex neurodynamics may play a role for the functions of cortical structures. While microscopic random noise may trigger meso- or macroscopic states, the nonlinear dynamics at these levels may also affect the activity at the microscopic level.
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| 21. |
- Liljenström, Hans
(författare)
-
Dialog - en väg till ökad förståelse?
- 2010
-
Ingår i: Bortom tro och vetande - tankar från en dialog. - 9789173313582 ; , s. 96-126
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 22. |
- Liljenström, Hans
(författare)
-
Editorial Introduction
- 2018
-
Ingår i: Journal of Consciousness Studies. - 1355-8250. ; 25, s. 8-12
-
Annan publikation (refereegranskat)
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| 23. |
- Liljenström, Hans
(författare)
-
Evolving complexity, cognition, and consciousness
- 2012
-
Ingår i: Science and Culture Series - Astrophysics. ; , s. 171-188
-
Konferensbidrag (refereegranskat)abstract
- All through the history of the universe there is an apparent tendency for increasing complexity, with the organization of matter in evermore elaborate and interactive systems. The living world in general, and the human brain in particular, provides the highest complexity known. It seems obvious that all of this complexity must be the result of physical, chemical and biological evolution, but it was only with Darwin that we began to get a scientific understanding of biological evolution. Darwinian principles are guiding in our understanding of such complex systems as the nervous system, but also for the evolution of human society and technology. Living organisms have to survive in a complex and changing environment. This implies response and adaption to environmental events and changes at several time scales. The interaction with the environment depends on the present state of the organism, as well as on previous experiences stored in its molecular and cellular structures. At a longer time scale, organisms can adapt to slow environmental changes, by storing information in the genetic material carried over from generation to generation. This phylogenetic learning is complemented by ontogenetic learning, which is adaptation at a shorter time scale, occuring in non -genetic structures. The evolution of a nervous system is a major transition in biological evolution and allows for an increasing capacity for information storage and processing, increasing chances of survival. Such neural knowledge processing, cognition, shows the same principal features as non neural adaptive processes. Similarly, consciousness might appear, to different degrees, at different stages in evolution. Both cognition and consciousness depends critically on the organization and complexity of the organism. In this presentation, I will briefly discuss general principles for evolution of complexity, focussing on the evolution of the nervous system, which provides organisms with ever increasing capacity for complex behaviour, cognition and consciousness. I will also discuss some computational approaches, as tools for understanding relations between structure, dynamics and function of the nervous system.
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| 24. |
- Liljenström, Hans
(författare)
-
Free Will and Spatiotemporal Neurodynamics
- 2014
-
Ingår i: Advances in cognitive neurodynamics. - 2213-3569. ; 4, s. 521-527
-
Konferensbidrag (refereegranskat)abstract
- It is widely assumed that neuroscience has proved that conscious will is an illusion. Indeed, a number of experimental results seem to indicate that conscious will is not causally related to the willed action, i.e. epiphenomenal. There are, however, alternative ways of interpreting the results that these conclusions are based on, and this paper examines the scientific arguments and experiments regarding conscious will. We argue that there is, as yet, no empirical support for epiphenomenal conscious will, and that the alternative hypothesis, that conscious will is causative, is also consistent with experimental data. We also use computational models and simulations to demonstrate that local neural impulses may trigger global oscillatory activity after a substantial delay period, supporting the idea that intentional impulses may be part of a conscious will experience.
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| 25. |
- Liljenström, Hans
(författare)
-
Freeman Neurodynamics The Past 25 Years
- 2018
-
Ingår i: Journal of Consciousness Studies. - 1355-8250. ; 25, s. 13-32
-
Tidskriftsartikel (refereegranskat)abstract
- Walter Freeman established a unique approach for interpreting brain processes, perception, cognition, and intentionality. Freeman's neurodynamics approach evokes the concepts of mass action and synchrony in neural populations, and even today is far ahead of the field of dynamical systems in hierarchical brain models. He summarized the essence of his views on the physiology of perception in a landmark paper on the pages of Scientific American in 1991. He spelled out the main components of his neurodynamics theory in that essay, which became a classic in brain theory and cognition. His approach has been hailed by many and attracted a large number of scientists all over the world. At the same time there were fellow scientists who objected to Freeman's approach and dismissed its basic tenets. This love or hate relationship followed Freeman until his death in his home in Berkeley, on 24 April 2016. In the present contribution we review the progress of Freeman's theory of neurodynamics over the past 25 years. We describe his work in light of new developments in experimental and theoretical approaches to brain dynamics, establishing new directions in computational neuroscience, cognitive monitoring, computational and mathematical modelling, field theories of cognition and intelligence, and his quest towards inventing novel engineering applications.
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| 26. |
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| 27. |
- Liljenström, Hans
(författare)
-
Inducing Transitions in Mesoscopic Brain Dynamics
- 2010
-
Ingår i: Modeling Phase Transitions in the Brain. - New York, NY : Springer New York. - 9781441907950 ; :4, s. 147-177
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 28. |
- Liljenström, Hans
(författare)
-
Intention and Attention in Consciousness Dynamics and Evolution
- 2011
-
Ingår i: Journal of Cosmology. - 2159-063X. ; 14, s. 4848-4858
-
Tidskriftsartikel (refereegranskat)abstract
- All through the history of the universe there is an apparent tendency for increasing complexity, with the organization of matter in evermore elaborate and interactive systems. The living world in general, and the human brain in particular, provides the highest complexity known. Presumably, the neural system with its complex dynamics has evolved to cope with the complex dynamics of the environment, where it is embedded. The evolution of a nervous system constitutes a major transition in biological evolution and allows for an increasing capacity for information storage and processing. Neural knowledge processing, cognition, shows the same principal features as non-neural adaptive processes. Similarly, consciousness might appear, to different degrees, at different stages in evolution. Both cognition and consciousness seem to depend critically on the organization and complexity of the organism. Different states of consciousness can apparently be associated with different levels of neural activity, in particular with different oscillatory modes at the mesoscopic level of cortical networks. Transitions between such modes could also be related to transitions between different states of consciousness. For example, a transition from an awake to an anaesthetized state, or sleep, is accompanied by a transition from high frequency oscillations to low frequency oscillations in the cortical neurodynamics. In this article, I will briefly discuss some general aspects on the evolution of the nervous system and its complex neurodynamics, which provides organisms with ever increasing capacity for complex behaviour, cognition and consciousness. Consciousness and cognition apparently evolve through interaction with the environment, where the organism is embedded. Such exploration of the environment requires both attention and intention. I will discuss these dual and complementary aspects of consciousness, and their effects as perception and action. Finally, I will speculate on consciousness related to life, and how it may be regarded as a driving force in the exploration of our world
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| 29. |
- Liljenström, Hans
(författare)
-
Intentionality as a Driving Force
- 2018
-
Ingår i: Journal of Consciousness Studies. - 1355-8250. ; 25, s. 206-229
-
Tidskriftsartikel (refereegranskat)abstract
- Intentionality - in the sense of purposiveness - is essential for the action perception cycle, which is central in Walter Freeman's work. In this paper, I will reflect upon Walter Freeman's view on intentionality and its relation to mesoscopic neurodynamics, also quoting him from a couple of unique dialogues. Further, I will elaborate on the role of intentionality for decision making and free will, in particular focusing on intentionality as a driving force in evolution and in life in general. I will also describe briefly a computational model of decision making and put that model in the broader context of the action perception cycle. Finally, in some philosophical comments on consciousness, I will discuss its dual aspects of intention and attention, which appears to be causally effective in the material world.
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| 30. |
- Liljenström, Hans
(författare)
-
Mesoscopic Brain Dynamics
- 2012
-
Ingår i: Scholarpedia. - : Scholarpedia. - 1941-6016. ; 7, s. 4601-
-
Tidskriftsartikel (refereegranskat)abstract
- Mesoscopicbraindynamicsusually refers to theneuralactivity or dynamics at intermediate scales of thenervous system, at levels between neurons and the entire brain. It is commonly considered to relate to the dynamics of cortical neural networks, typically on the spatial order of a few millimeters to centimeters, and temporally on the order of milliseconds to seconds. It is usually the type of dynamics that can be measured by methods such as ECoG (electrocorticography),EEG(electroencephalography), LFP (local field potentials) orMEG(magnetoencephalography). Indeed, the terminology can be used in relative terms, where “meso” just indicates that the scale of interest is in between the “micro” and the “macro”.
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| 31. |
- Liljenström, Hans
(författare)
-
Mesoscopic Brain Dynamics and Mental Disorders
- 2011
-
Ingår i: European Psychiatry. - 0924-9338 .- 1778-3585. ; 26, s. 2225-2225
-
Konferensbidrag (refereegranskat)abstract
- Mesoscopic brain dynamics, typically studied with electro- and magnetoencephalography (EEG and MEG), display a rich complexity of oscillatory and chaotic-like states, including many different frequencies, amplitudes and phases. Presumably, these different dynamical states correspond to different mental states and functions, and studying transitions between such states could provide valuable insights into brain–mind relations that should also be of clinical interest. We use computational methods to investigate these transitions, with the objective of finding relations between structure, dynamics, and function. In particular, we have developed models of paleo- and neocortical structures, in order to study their mesoscopic neurodynamics, as a link between the microscopic neuronal and macroscopic mental events and processes. I will describe several types of models that emphasize network connectivity and structure, but which also include molecular and cellular properties at varying detail, depending on the particular problem and experimental data available. We use these models to study how phase transitions can be induced in the mesoscopic neurodynamics of cortical networks by internal (natural) and external (artificial) factors. I will discuss the models, and relate the simulation results to macroscopic phenomena, such as arousal, attention, anaesthesia, learning, and certain mental disorders
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| 32. |
- Liljenström, Hans
(författare)
-
Modeling effects of neural fluctuations and inter-scale interactions
- 2018
-
Ingår i: Chaos. - : AIP Publishing. - 1054-1500 .- 1089-7682. ; 28
-
Tidskriftsartikel (refereegranskat)abstract
- One of the greatest challenges to science, in particular, to neuroscience, is to understand how processes at different levels of organization are related to each other. In connection with this problem is the question of the functional significance of fluctuations, noise, and chaos. This paper deals with three related issues: (1) how processes at different organizational levels of neural systems might be related, (2) the functional significance of non-linear neurodynamics, including oscillations, chaos, and noise, and (3) how computational models can serve as useful tools in elucidating these types of issues. In order to capture and describe phenomena at different micro (molecular), meso (cellular), and macro (network) scales, the computational models need to be of appropriate complexity making use of available experimental data. I exemplify by two major types of computational models, those of Hans Braun and colleagues and those of my own group, which both aim at bridging gaps between different levels of neural systems. In particular, the constructive role of noise and chaos in such systems is modelled and related to functions, such as sensation, perception, learning/memory, decision making, and transitions between different (un-)conscious states. While there is, in general, a focus on upward causation, I will also discuss downward causation, where higher level activity may affect the activity at lower levels, which should be a condition for any functional role of consciousness and free will, often considered to be problematic to science. Published by AIP Publishing.
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| 33. |
- Liljenström, Hans
(författare)
-
Multi-scale Causation in Brain Dynamics
- 2016
-
Ingår i: Cognitive Phase Transitions in the Cerebral Cortex - Enhancing the Neuron Doctrine by Modeling Neural Fields. - Cham : Springer International Publishing. - 9783319244044 ; 39:39, s. 177-186
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- For any complex system, consisting of several organizational levels, the problem of causation is profound. Usually, science considers upward causation as funda-mental, paying less or no attention to any downward causation. This is also true for the nervous system, where cortical neurodynamics, or even higher mental functions of the brain are normally considered causally dependent on the nerve cell activity, or even the activity at the ion channel level. This study presents both upward and downward causation in cortical neural systems, using computational methods with focus on cortical fluctuations. We have developed models of paleo- and neocortical structures, in order to study their mesoscopic neurodynamics, as a link between the microscopic neuronal and macroscopic mental events and pro-cesses. We demonstrate how both noise and chaos may play a role for the func-tions of cortical structures. While microscopic random noise may trigger meso- or macroscopic states, the nonlinear dynamics at these levels may also affect the ac-tivity at the microscopic level.
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| 34. |
- Liljenström, Hans
(författare)
-
Network Effects of Synaptic Modifications
- 2010
-
Ingår i: Pharmacopsychiatry. - : Georg Thieme Verlag KG. - 0176-3679 .- 1439-0795. ; 43, s. S67-S81
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we use computational models of varying complexity to investigate the role of synaptic modifications for cortical network properties. In particular, we study how the dynamics can be regulated by neuromodulators, intrinsic noise and chemical agents. We focus on the complex neurodynamics and its modulation, and how this is related to the neural circuitry, where connectivity enhancement and pruning is considered. The emphasis is on the overall net-work structures, with feedforward and feedback loops between excitatory and inhibitory neurons at several layers and distances, and less details at the synaptic level. Our models aim at linking processes at a molecular and cellular (microscale), with processes at a network level (mesoscale), which in turn are linked to the mental processes and cognitive functions (macroscale). We also discuss the relevance of these results for clinical and experimental neuroscience, with applications to learning, memory, arousal, and mental disorders.
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| 35. |
- Liljenström, Hans, et al.
(författare)
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Neurodynamics of Decision-Making—A Computational Approach
- 2016
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Ingår i: Advances in Cognitive Neurodynamics (V). - Singapore : Springer Singapore. - 9789811002052 ; :5, s. 41-47
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Bokkapitel (refereegranskat)abstract
- Decision-making is a complex process that normally seems to involve several brain structures. In particular, amygdala, orbitofrontal cortex (OFC), and lateral prefrontal cortex (LPFC) seem to be essential in human decision-making, where both emotional and cognitive aspects are taken into consideration. In this paper, we present a stochastic population model representing the neural information processing of decision-making, from perception to behavioral activity. We model the population dynamics of the three neural structures significant in the decision-making process (amygdala, OFC, and LPFC), as well as their interaction. In our model, amygdala and OFC represent the neural correlates of secondary emotion, while the activity of OFC neural populations represents the outcome expectancy of alternatives, and the cognitive aspect of decision-making is controlled by LPFC. The results may have implications for how we make decisions for our individual actions, as well as for societal choices, where we take examples from transport and its impact on climate change.
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| 36. |
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| 37. |
- Liljenström, Hans
(författare)
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On Color Texture Generating Based on Simplified KIII Model
- 2009
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Konferensbidrag (refereegranskat)abstract
- KIII model is an olfactory neural networks bionic model proposed by Walter J. Freeman. Its architecture simulates that of olfactory neural system, which is different from other artificial neural networks. Through simplifying KIII model, a color texture generating algorithm is proposed combining with RGB. In RGB space, the tricolor of each pixel (red, green and blue) is used as the model input and the model output is composed as the tricolor of corresponding pixel in generated texture image. Experimental results show that simplified KIII model can generate beautiful color texture images
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| 38. |
- Liljenström, Hans
(författare)
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Peak experiences in a consciousness landscape - report on the science of consciousness conference in Interlaken, Switzerland, 2019
- 2019
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Ingår i: Journal of Consciousness Studies. - 1355-8250. ; 26, s. 238-263
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Introduction The Science of Consciousness (TSC) 2019 was the 26th international interdisciplinary conference in the series that started in Tucson in 1994. This one was held in late June in the beautiful Swiss town of Interlaken, between two lakes and surrounded by high alps. The local organizer was Harald Atmanspacher from Collegium Helveticum in Zurich, assisted by the “eternal” main organizer, Stuart Hameroff from the Center for Consciousness Studies in Tucson. There was no special theme for this conference, but I agree with the introductory comment in the abstract book: “Despite remarkable empirical and theoretical progress, consciousness is not understood yet, and therefore the field will benefit from a healthy scientific attitude that includes openness to multiple perspectives”. This was certainly applicable here. The beautiful alpine landscape provided a perfect setting for the conference, but the unexpectedly hot weather made it hard to concentrate and contemplate on the deep questions discussed. Yet, the organizers had done what they could to make the conference welcoming and inspiring for the 620 participants from about 30 countries. There were in total 24 invited talks in 9 plenary sessions, 105 oral presentations in concurrent sessions, and 220 posters - on topics, such as connectomics, placebo research, first-person experience, anesthetics, psychedelics, plant cognition, quantum biology, dual-aspect monism, bistable perception, insight, religious studies, evolution, and language. More details on the conference, including video recordings of the plenary talks are available on the website, www.tsc2019-interlaken.ch. This will be a very subjective report, where I have cherry-picked among the talks I attended, primarily focusing on the plenaries, but with some visits to concurrent sessions. In addition, I will not give equal amount of space to all the presentations I refer to, and apologize if anyone feels mistreated that way. It also goes without saying that the report is biased with respect to my own research interests, as a biophysicist working with neurocomputational models of decision making, based on mesoscopic neurodynamics. Inspired by the surrounding alpine landscape, I think it could serve as a metaphor for the mental landscape and intellectual challenges we have to climb when trying to understand the ancient conundrum of consciousness. The perspectives provided by various research areas, can then be likened with different alps, with rather deep valleys between. Somewhat arbitrary, I will structure my report around three major peak perspectives, Physics, Biology, and Metaphysics, where I have roughly and not chronologically grouped the various presentations.
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| 39. |
- Liljenström, Hans
(författare)
-
Phase Transitions in Mesoscopic Brain Dynamics : Implications for Cognition and Consciousness
- 2009
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Konferensbidrag (refereegranskat)abstract
- Mesoscopic brain dynamics, typically studied with electroand magnetoencephalography (EEG and MEG) display a rich complexity of oscillatory and chaotic-like states, including many different frequencies, amplitudes and phases. Presumably, these different dynamical states correspond to different mental states and functions, and to study transitions between such states could give us valuable insight in brain-mind relations that should also be of clinical interest. We use computational methods to address these problems, with an objective to find relations between structure, dynamics and function. In particular, we have developed models of paleo- and neocortical structures, in order to study their mesoscopic neurodynamics, as a link between the microscopic neuronal and macroscopic mental events and processes. In this presentation, I will describe different types of models, where the emphasis is on network connectivity and structure, but also including molecular and cellular properties at varying detail, depending on the particular problem and experimental data available. We use these models to study how phase transitions can be induced in the mesoscopic neurodynamics of cortical networks by internal (natural) and external (artificial) factors. We relate and discuss the models and simulation results to macroscopic phenomena, such as arousal, attention, anaesthesia, learning, and mental disorders
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| 40. |
- Liljenström, Hans
(författare)
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Review for Cognitive Systems Research of the book The Brain and AI, by authors Karl Schlagenhauf and Fanji Gu
- 2020
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Ingår i: Cognitive Systems Research. - : Elsevier BV. - 1389-0417. ; 64, s. 29-36
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Tidskriftsartikel (refereegranskat)abstract
- The human brain is often considered the most complex system known. It has a fantastic capacity to learn and remember, to recognize patterns in space and time, solve problems of all kinds, innovate tools and machines, create beautiful art and science. Is it reasonable to believe that we, in a foreseeable future, will be able to understand all the wonders of our own brain, enough to be able to mimic it and build artificial brains and minds that correspond to or even surpass the capacity of the human origin? Can we seriously believe that we (soon, or ever) will be able to build robots that know of and can reflect upon their own existence?This review of the book, The Brain and AI, deals with such issues, but in a very special way. It is written as a fascinating dialogue between the two authors, Chinese scientist Fanji Gu and German engineer Karl Schlagenhauf, where they discuss the development of neuroscience and artificial intelligence (AI) with a critical examination of given "truths" in these fields. The Brain and AI is indeed worth reading for many reasons, regardless if you are a student or researcher in any of the many fields of science discussed here (e.g. physics, computer science, neuroscience, cognitive science psychology, social science), or if you are just interested in the current and future development of brain research and artificial intelligence. The book is both educating and entertaining and can be strongly recommended. (C) 2020 The Author. Published by Elsevier B.V.
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| 41. |
- Liljenström, Hans, et al.
(författare)
-
Scoping Report on Socio-Economic and Land Use Dynamics in the Stockholm-Mälar Region
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This scoping report for the COMPLEX work package 4 (WP4) on Socio-Economic and Land Use Dynamics in the Stockholm-Mälar Region has several objectives. The first is to present and outline the state-of-the-art, including a literature review, with regard to complex pathways to a low carbon society, with special relevance to the Stockholm-Mälar region. It will do so in a larger context of complex socio-natural systems, with an emphasis on a green economy, bioen-ergy and land use, as well as on societal transformation and behavioural change. Another objec-tive is to inform primarily our partners in COMPLEX, but also others who might be interested, including stakeholders in our study region. Perhaps the most important objective with this re-port is to provide a basis for the collaborative work within our work package, and with our col-leagues elsewhere. In this second revised version of the report, we have extended some parts, and shortened others, depending on suggestions and interesting new information. A part of this new information has come from a stakeholder workshop held in Sigtuna in early 2014, which to a great extent could contribute to a more elaborate analysis of stakeholder and policy maker positions. In addition, there is now a more extensive description of relevant land use modelling. The illustrations included in this report are extracted from scientific articles and other material that we are referring to. Their origin is explicitly cited but no copyright authorization has been requested, while this report is intended primarily for internal spread and use within the COM-PLEX consortium and its networks.
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| 42. |
- Liljenström, Hans, et al.
(författare)
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Signatures of Depression in Non-Stationary Biometric Time Series
- 2009
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Ingår i: Computational Intelligence and Neuroscience. - : Hindawi Limited. - 1687-5265 .- 1687-5273. ; 2009
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Tidskriftsartikel (refereegranskat)abstract
- This paper is based on a discussion that was held during a special session on models of mental disorders, at the NeuroMath meeting in Stockholm, Sweden, in September 2008. At this occasion, scientists from different countries and different fields of research presented their research and discussed open questions with regard to analyses and models of mental disorders, in particular depression. The content of this paper emerged from these discussions and in the presentation we briefly link biomarkers (hormones), bio-signals (EEG) and biomaps (brain-maps via EEG) to depression and its treatments, via linear statistical models as well as nonlinear dynamic models. Some examples involving EEG-data are presented
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| 43. |
- Liljenström, Hans
(författare)
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Study on Single-Channel EEG Pattern Induced by Acupuncture
- 2016
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Ingår i: Advances in Cognitive Neurodynamics (V). - Singapore : Springer Singapore. - 9789811002076 ; :5, s. 485-491
-
Bokkapitel (refereegranskat)abstract
- A new approach for recognizing single-channel EEG pattern induced by acupuncture on acupoint of Zusanli was presented. EEG was decomposed by ensemble empirical mode decomposition (EEMD) into a small number of intrinsic mode functions (IMFs) based on intrinsic local characteristic time scale. The power, standard deviation, and analytic amplitude of first two IMFs expressed the difference between normal EEG and EEG affected by acupuncture. The two EEG patterns could be classified by extreme learning machine (ELM) with faster and better classification performance compared with BP. Similar classification accuracy of different channels indicated the global EEG pattern affected by acupuncture.
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| 44. |
- Liljenström, Hans
(författare)
-
Study on the EEG Rhythm in Meditation
- 2014
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Ingår i: Advances in cognitive neurodynamics. - 2213-3569. ; 4, s. 99-107
-
Konferensbidrag (refereegranskat)abstract
- Meditation affects the brain rhythm significantly. Compared with 4 non-meditators, the power of delta band was lower while high frequency band was 5 higher for a meditator. Alpha band over the scalp was much more active in normal 6 state for meditator with decreased dominant alpha frequency. Obvious transient 7 process between normal eyes-closed rest and meditation was observed after EEG 8 analysis. The active time and the power of beta and gamma band increased 9 significantly in meditation. The inter-hemispheric and intra-hemispheric coherence 10 beta and low gamma bands for meditative state were higher than normal state.
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| 45. |
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| 46. |
- Lin, Huayi, et al.
(författare)
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Modelling stakeholder satisfaction for conflict resolution in wildlife management: a case of wolf population in Sweden
- 2021
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Ingår i: European Journal of Wildlife Research. - : Springer Science and Business Media LLC. - 1612-4642 .- 1439-0574. ; 67
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish wolf population has rebounded from near extinction in the 1960s to around 365 individuals in 2020, after the implementation of the Hunting Act (jaktlagen) in 1966. This recent increase in the wolf population has evoked a serious divide between "pro-wolf" and "anti-wolf" Swedish citizens. Despite the continuous efforts by the Swedish government to reconcile this antagonism, the conflicts are persistent with a sign of impasse. In this paper, we present a modelling tool, which can bring transparent and "structured dialogue to the opposing positions." This approach includes a stylized framework for quantitative modelling of stakeholders' satisfaction levels regarding their preferred size of the wildlife population in question, based on the concept of satisfaction functions. We argue that this framework may contribute to conflict resolution by bringing a common understanding among stakeholders, facilitate a societal discourse, and potentially help to assess likely support for conservation policies. We present a showcase application of this modeling tool in the context of the conflict over the Swedish wolf conservation policies. The model is informed using a thorough literature review as well as interviews, which identified relevant stakeholder groups and respective drivers of their attitudes towards wolves.
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| 47. |
- Repsilber, Dirk, 1971-, et al.
(författare)
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Reverse engineering of regulatory networks : simulation studies on a genetic algorithm approach for ranking hypotheses
- 2002
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Ingår i: Biosystems (Amsterdam. Print). - Ireland : Elsevier. - 0303-2647 .- 1872-8324. ; 66:1-2, s. 31-41
-
Tidskriftsartikel (refereegranskat)abstract
- Reverse engineering algorithms (REAs) aim at using gene expression data to reconstruct interactions in regulatory genetic networks. This may help to understand the basis of gene regulation, the core task of functional genomics. Collecting data for a number of environmental conditions is necessary to reengineer even the smallest regulatory networks with reasonable confidence. We systematically tested the requirements for the experimental design necessary for ranking alternative hypotheses about the structure of a given regulatory network. A genetic algorithm (GA) was used to explore the parameter space of a multistage discrete genetic network model with fixed connectivity and number of states per node. Our results show that it is not necessary to determine all parameters of the genetic network in order to rank hypotheses. The ranking process is easier the more experimental environmental conditions are used for the data set. During the ranking, the number of fixed parameters increases with the number of environmental conditions, while some errors in the hypothetical network structure may pass undetected, due to a maintained dynamical behaviour.
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| 48. |
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| 49. |
- Wahlund, B, et al.
(författare)
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Seizure (Ictal)--EEG characteristics in subgroups of depressive disorder in patients receiving electroconvulsive therapy (ECT)--a preliminary study and multivariate approach
- 2009
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Ingår i: Computational intelligence and neuroscience. - : Hindawi Limited. - 1687-5273 .- 1687-5265. ; , s. 965209-
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. Examine frequency distributions of ictal EEG after ECT stimulation in diagnostic subgroups of depression.Methods. EEG registration was consecutively monitored in 33 patients after ECT stimulation. Patients were diagnosed according to DSM IV and subdivided into: (1) major depressive disorder with psychotic features(n=7), (2) unipolar depression(n=20), and (3) bipolar depression(n=6).Results. Results indicate that the diagnostically subgroups differ in their ictal EEG frequency spectrumml: (1) psychotic depression has a high occurrence of delta and theta waves, (2) unipolar depression has high occurrence of delta, theta and gamma waves, and (3) bipolar depression has a high occurrence of gamma waves. A linear discriminant function separated the three clinical groups with an accuracy of 94%.Conclusion. Psychotic depressed patients differ from bipolar depression in their frequency based on probability distribution of ictal EEG. Psychotic depressed patients show more prominent slowing of EEG than nonpsychotic depressed patients. Thus the EEG results may be supportive in classifying subgroups of depression already at the start of the ECT treatment.
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