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- PublicationMetadata onlyA breakthrough in neuroscience needs a "Nebulous Cartesian System" Oscillations, quantum dynamics and chaos in the brain and vegetative system(ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2007-04) Başar, Erol; Güntekin, Bahar; TR142226; TR204666The Cartesian System is a fundamental conceptual and analytical framework related and interwoven with the concept and applications of Newtonian Dynamics. In order to analyze quantum processes physicist moved to a Probabilistic Cartesian System in which the causality principle became a probabilistic one. This means the trajectories of particles (obeying quantum rules) can be described only with the concept of cloudy wave packets. The approach to the brain-body-mind problem requires more than the prerequisite of modem physics and quantum dynamics. In the analysis of the brain-body-mind construct we have to include uncertain causalities and consequently multiple uncertain causalities. These multiple causalities originate from (1) nonlinear properties of the vegetative system (e.g. irregularities in biochemical transmitters, cardiac output, turbulences in the vascular system, respiratory apnea, nonlinear oscillatory interactions in peristalsis); (2) nonlinear behavior of the neuronal electricity (e.g. chaotic behavior measured by EEG), (3) genetic modulations, and (4) additional to these physiological entities nonlinear properties of physical processes in the body. The brain shows deterministic chaos with a correlation dimension of approx. D-2=6, the smooth muscles approx. D-2=3. According to these facts we propose a hyper-probabilistic approach or a hyper-probabilistic Cartesian System to describe and analyze the processes in the brain-body-mind system. If we add aspects as our sentiments, emotions and creativity to this construct, better said to this already hyper-probabilistic construct, this "New Cartesian System" is more than hyper-probabilistic, it is a nebulous system, we can predict the future only in a nebulous way; however, despite this chain of reasoning we can still provide predictions on brain-body-mind incorporations. We tentatively assume that the processes or mechanisms of the brain-body-mind system can be analyzed and predicted similar to the metaphor of '' finding the walking path in a cloudy or foggy day". This is meant by stating "The Nebulous Cartesian System" (NCS). Descartes, at his time undertaking his genius step, did not possess the knowledge of today's physiology and modem physics; we think that the time has come to consider such a New Cartesian System. To deal with this, we propose the utilization of the Heisenberg S-Matrix and a modified version of the Feynman Diagrams which we call "Brain Feynman Diagrams". Another metaphor to consider within the oscillatory approach of the NCS is the "string theory". We also emphasize that fundamental steps should be undertaken in order to create the own dynamical framework of the brain-body-mind incorporation; suggestions or metaphors from physics and mathematics are useful; however, the grammar of the brains intrinsic language must be understood with the help of a new biologically founded, adaptive-probabilistic Cartesian system. This new Cartesian System will undergo mutations and transcend to the philosophy of Henri Bergson in parallel to the Evolution theory of Charles Darwin to open gateways for approaching the brain-body-mind problem. (c) 2006 Published by Elsevier B.V.
- PublicationMetadata onlyA comparative analysis of sensory visual evoked oscillations with visual cognitive event related oscillations in Alzheimer's disease(ELSEVIER IRELAND LTD, ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND, 2009-09-25) Yener, Görsev G.; Güntekin, Bahar; Tülay, Elif; Başar, Erol; TR142226; TR142311; TR204666; TR143760We compared visual evoked oscillatory responses of subjects with Alzheimer's disease (AD) (n = 22) to healthy elderly controls (n = 19) elicited by simple light stimuli. The visual evoked oscillatory responses in AD subjects without cholinergic treatment (n = 11) show significant differences (df = 2.38. F = 4.957, P = 0.012) from the controls and the AD subjects treated with a cholinesterase inhibitor (n = 11). Higher theta oscillatory responses in untreated AD subjects are seen on the electrode locations over bi-parietal and right occipital regions after simple light stimuli with less, if any, cognitive load. These changes were restricted to the theta frequency range only and are related to location, frequency bands and drug effects. In our previous work we observed that visual event related oscillations elicited after the visual stimuli with a higher cognitive load, i.e. an oddball target, display lower amplitudes: between controls and AD subjects in delta frequency band without a drug effect, over the left and mid-central region. These differences between the visual evoked oscillations and the visual event related oscillations imply that there are at least two different cognitive circuits that are activated upon visual stimuli in AD patients. (c) 2009 Published by Elsevier Ireland Ltd.
- PublicationMetadata onlyA comparative study of auditory and visual event related coherences(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2012-09) Başar, Erol; Tülay, Elif; Turp Gölbaşı, Bilge; Güntekin, Bahar; 142226; 204666
- PublicationMetadata onlyA multicenter study on Alzheimer's disease: comparison of total Tau, p-Tau and a beta(1-42) levels across three centers in Turkey(Wiley-Blackwell, 111 River St, Hoboken 07030-5774, Nj Usa, 2015-09) Yener, Görsev G.; 143760
- PublicationMetadata onlyA new biomarker proposal for the conversion from mild cognitive impairment to Alzheimer's disease: an event-related oscillations study(Wiley-Blackwell, 111 River St, Hoboken 07030-5774, Nj Usa, 2015-09) Yener, Görsev G.; Emek Savaş, Derya Durusu; Çavuşoğlu, Berrin; Güntekin, Bahar; Ada, Emel; 143760; 227002; 204666; 2198
- PublicationOpen AccessA New Interpretation Of P300 Responses Upon Analysis Of Coherences(Springer, Van Godewijckstraat 30, 3311 Gz Dordrecht, Netherlands, 2010-06) Güntekin, Bahar; Başar, Erol; TR142226; TR204666Previous studies on cognitive dynamics showed that oscillatory responses of P300 are composed of mainly delta and theta responses. In the present study, for the first time, the long-distance intra-hemispheric event related coherence (auditory oddball paradigm) and evoked coherence (simple sound) were compared in order to evaluate the effects of cognitive tasks on the long-distance coherences. Seventeen healthy subjects (8 female, 9 male) were included in the study. The coherence was analyzed for delta (1-3.5 Hz), theta (4-7.5 Hz) and alpha (8-13 Hz) frequency ranges for (F(3)-P(3), F(4)-P(4), F(3)-T(7), F(4)-T(8), F(3)-O(1,) F(4)-O(2)) electrode pairs. The coherence to target responses were higher than the non-target and simple auditory response coherence. This difference is significant for the delta coherence for both hemispheres and for theta coherences over the left hemisphere. The highest coherences were recorded at fronto-temporal locations for all frequency bands (delta, theta, alpha). Furthermore, fronto-parietal coherences were higher than the fronto-occipital coherences for all frequency bands (delta, theta, alpha).These results show that the fronto-temporal and fronto-parietal connections are most relevant for the identification of the target signal. This analysis open the way for a new interpretation of dynamic localization results during cognitive tasks.
- PublicationMetadata onlyA Proposal to Extend Brodmann's Areas Concept to a New Model(Anka Publisher, 116-11 Sok No.10 K 2 D 2, Bornova, Izmir 35050, Turkey, 2014) Başar, Erol; Düzgün, Aysel; Güntekin, Bahar; 142226; 204666Since the beginning of the last century, the localization of brain function is presented by Brodmann areas, or maps that are a result of anatomic organization. They are used in order to give a global idea of cortical structures for given sensory cognitive functions. In the last decades, the analysis of brain oscillations gained high importance for the correlation of brain functions. Moreover, the use of the spectral connectivity provides information on dynamic connectivity between various structures. Beside this, according to (Luria, 1966), brain responses have dynamic features and structural localization is almost impossible. According to these uses, brain functions are very difficult to localize and need joint analysis of oscillation and event related coherences. In the present report, a model called "CLAIR" is described to extend and possibly to replace the concept of the Brodmann areas. To design a perfect functioning CLAIR model requires years; however, the beginning step is provided in the present report.
- PublicationMetadata onlyA review of alpha activity in integrative brain function: Fundamental physiology, Sensory coding, cognition and pathology(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2012-10) Başar, Erol; TR142226Aim of the review: Questions related to the genesis and functional correlates of the brain's alpha oscillations around 10 Hz (Alpha) are one of the fundamental research areas in neuroscience. In recent decades, analysis of this activity has been not only the focus of interest for description of sensory-cognitive processes, but has also led to trials for establishing new hypotheses. The present review and the companion review aim to constitute an ensemble of "reasonings and suggestions" to understand alpha oscillations based on a wide range of accumulated findings rather than a trial to launch a new "alpha theory". Surveyed descriptions related to physiology and brain function: The review starts with descriptions of earlier extracellular recordings, field potentials and also considers earlier alpha hypotheses. Analytical descriptions of evoked and event-related responses, event-related desynchronization, the relationship between spontaneous activity and evoked potentials, aging brain, pathology and alpha response in cognitive impairment are in the content of this review. In essence, the gamut of the survey includes a multiplicity of evidence on functional correlates in sensory processing, cognition, memory and vegetative system, including the spinal cord and heart. (C) 2012 Elsevier B.V. All rights reserved.
- PublicationMetadata onlyA review of brain oscillations in cognitive disorders and the role of neurotransmitters(ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2008-10-15) Başar, Erol; Güntekin, Bahar; TR142226; TR204666The analysis of the functional correlates of "brain oscillations" has become an important branch of neuroscience. Although research on the functional correlates of brain oscillation has progressed to a high level, studies on cognitive disorders are rare and mainly limited to schizophrenia patients. The present review includes the results of the changes in brain oscillations in patients with Alzheimer's, schizophrenia, bipolar disorders, mild cognitive impairment, attention-deficit hyperactivity disorder (ADHD), alcoholism and those with genetic disorders. Furthermore, the effects of pharmaca and the influence of neurotransmitters in patients with cognitive disorders are also reviewed. Following the review, a short synopsis is given related to the analysis of brain oscillations. (c) 2008 Elsevier B.V. All rights reserved.
- PublicationMetadata onlyA Review of Brain Oscillations in Perception of Faces and Emotional Pictures(Pergamon-Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1Gb, England, 2014-05) Güntekin, Bahar; Başar, Erol; 204666; 142226The differentiation of faces, facial expressions and affective pictures involves processes of higher mental activity that have considerable applications in the psychology of moods and emotions. At present, the search for functional correlates of brain oscillations is an important trend in neuroscience. Furthermore, analyses of oscillatory responses provide key knowledge on the physiology of brain dynamics. Studies analysing oscillatory dynamics in face perception and emotional pictures have increased in recent years; however, the literature lacks a review of the current state of the art. This study provides a comprehensive review of the delta, theta, alpha, beta and gamma oscillatory responses on presentation of faces, facial expressions and affective pictures (International Affective Picture System, IAPS). The reviewed literature revealed that the brain is more sensitive to emotional stimuli than neutral stimuli. A common and reliable finding from all reviewed studies was the increased brain responsiveness towards negative emotional pictures (face expression or IAPS). (C) 2014 Elsevier Ltd. All rights reserved.
- PublicationMetadata onlyA Review of Gamma Oscillations in Healthy Subjects and in Cognitive Impairment(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2013-11) Başar, Erol; 142226This review describes a wide range of functional correlates of gamma oscillations in whole-brain work, in neuroethology, sensory-cognitive dynamics, emotion, and cognitive impairment. This survey opens a new window towards understanding the brain's gamma activity. Gamma responses are selectively distributed in the whole brain, and do not reflect only a unique, specific function of the nervous system. Sensory responses from cortex, thalamus, hippocampus, and reticular formations in animal and human brains, and also cognitive responses, were described by several authors. According to reviewed results, it becomes obvious that cognitive disorders, and medication which influence the transmitter release change entirely the understanding of the big picture in cognitive processes. Gamma activity is evoked or induced by different sensory stimuli or cognitive tasks. Thus, it is argued that gamma-band synchronization is an elementary and fundamental process in whole-brain operation. In conclusion, reasoning and suggestions for understanding gamma activity are highlighted. (C) 2013 Elsevier B.V. All rights reserved.
- PublicationMetadata onlyA short review of alpha activity In cognitive processes and in cognitive impairment(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2012-10) Başar, Erol; Güntekin, Bahar; TR142226; TR204666Aim of the report: In the companion report (Basar, this volume), the physiological fundaments of alpha activity in integrative brain function are described. The present report is a review of the significant role of alpha activity in memory and cognitive processes in healthy subjects, and in cognitive impairment. The role of neurotransmitters is also described, briefly, in this context. Towards an understanding of brain alpha: Despite numerous experimental studies, it is indicated that the presented results are only appropriate to establish an ensemble of reasonings and suggestions for analyzing "alphas" in the whole brain. In turn, in the near future, these reasonings and suggestions may serve (or are indispensable to serve) as fundaments of more general and tenable hypotheses on the genesis and function of "alphas". (C) 2012 Elsevier B.V. All rights
- PublicationMetadata onlyAbnormal event related EEG delta coherence in Parkinson type of dementia during the visual oddball paradigm(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-10) Güntekin, Bahar; Çadırcı, Fadime; Mantar, Nagihan; Yılmaz, Nesrin; Özer, Fahriye Feriha; Hanoğlu, Lütfü; Yener, Görsev G.; Başar, Erol; 204666; 259227; 259226; 38782; 171122; 143760; 142226
- PublicationMetadata onlyAffective pictures processing is reflected by an increased long-distance EEG connectivity(Springer, Van Godewijckstraat 30, 3311 Gz Dordrecht, Netherlands, 2017-08) Güntekin, Bahar; Femir, Banu; Turp Gölbaşı, Bilge; Tülay, Elif; Başar, Erol; 204666; 142226Analysis of affective picture processing by means of EEG has invaded the literature. The methodology of event-related EEG coherence is one of the essential methods used to analyze functional connectivity. The aims of the present study are to find out the long range EEG connectivity changes in perception of different affective pictures and analyze gender differences in these long range connected networks. EEGs of 28 healthy subjects (14 female) were recorded at 32 locations. The participants passively viewed emotional pictures (IAPS, unpleasant, pleasant, neutral). The long-distance intra-hemispheric event-related coherence was analyzed for delta (1-3.5 Hz), theta (4-7.5 Hz), and alpha (8-13 Hz) frequency ranges for F-3-T-7, F-4-T-8, F-3-TP7, F-4-TP8, F-3-P-3, F-4-P-4, F-3-O-1, F-4-O-2, C-3-O-1, C-4-O-2 electrode pairs. Unpleasant pictures elicited significantly higher delta coherence values than neutral pictures (p < 0.05), over fronto-parietal, fronto-occipital, and centro-occipital electrode pairs. Furthermore, unpleasant pictures elicited higher theta coherence values than pleasant (p < 0.05) and neutral pictures (p < 0.05). The present study showed that female subjects had higher delta (p < 0.05) and theta (p < 0.05) coherence values than male subjects. This difference was observed more for emotional pictures than for neutral pictures. This study showed that the brain connectivity was higher during emotional pictures than neutral pictures. Females had higher connectivity between different parts of the brain than males during emotional processes. According to these results, we may comment that increased valence and arousal caused increased brain activity. It seems that not just single sources but functional networks were also activated during perception of emotional pictures.
- PublicationMetadata onlyAn essay on Darwin's theory and Bergson's creative evolution in the era of neuroQuantology(Anka Publisher, 116-11 Sok No.10 K 2 D 2, Bornova, Izmir 35050, Turkey, 2009) Başar, Erol; Güntekin, Bahar; TR204666; TR142226Charles Darwins's evolution theory was surveyed and analyzed by Henri Bergson in his book "Evolution Creatrice" (1907). Bergson described the importance of "intuition" and "cognitive processes" during evolution. The present essay describes the importance of entropy changes during evolution of species and development of cognition and intuition. The importance of Bergson's philosophy in modern sciences is globally explained.
- PublicationMetadata onlyAssociation Of Peripheral Visfatin Levels And Visfatin G-948T Gene Polymorphism With Alzheimer's Disease In A Turkish Population(Güneş Kitabevi Ltd Sti, M Rauf Inan Sok No 3, Ankara, Sıhhıye 06410, Turkey, 2013) Vurgun, Ufuk; Şahin, Özlem; Tüfekçi, Kemal Uğur; Keskinoğlu, Pembe; Yener, Görsev; Genç, Kemal Kürşad; Genç, Sermin; 167754; 190994; 143760; 166828; 2453Introduction: Visfatin is a pleiotropic cytokine implicated in several physiological and pathophysiological processes such as innate immunity, cellular metabolism, longevity, and inflammation. Altered visfatin levels and visfatin gene polymorphisms have been reported in various human diseases, including type 2 diabetes mellitus, rheumatoid arthritis, obesity, coronary artery disease and stroke.. Materials and Method: In this study, we investigated whether serum visfatin levels were changed in volunteers with Alzheimer's disease (AD) (n = 40) or healthy controls (n=40) and whether visfatin gene G-948T polymorphism was associated with the disease. Results: Visfatin levels were not significantly different in AD patients compared with healthy aged control subjects. In this relatively small population, we found a significant, but weak association between GT heterozygous genotype at position -948 of visfatin gene and AD. However, there was no association between G-948T polymorphism and visfatin levels, and any demographic, anthropometric or biochemical parameters. Conclusion: Further studies in larger and different populations are needed to fully elaborate the involvement of visfatin gene in AD.
- PublicationOpen AccessAuditory Delta Event-related Oscillatory Responses are Decreased in Alzheimer's Disease(Ios Press, Nieuwe Hemweg 6B, 1013 Bg Amsterdam, Netherlands, 2012) Başar, Erol; Yener, Görsev; Güntekin, Bahar; Necioğlu Örken, Dilek; Forta, H.; 142226; 143760; 204666Background: Visual delta event-related (ERO) and evoked oscillations (EO) of Alzheimer patients (AD) are different than healthy. In the present study, the analysis is extented to include auditory ERO and EO in AD. The rationale is to reveal whether the auditory ERO delta responses are also reduced, and whether this is a general phenomenon in Alzheimer patients upon applying stimuli with cognitive load. Methods.: Thirty-four mild AD subjects 117 de-novo and 17 medicated (cholinergic)l and seventeen healthy controls were included. Auditory oddball paradigm and sensory auditory stimuli were applied to the subjects. Oscillatory responses were analyzed by measuring maximum amplitudes in delta frequency range (0.5-3.5 Hz). Results: Auditory delta ERO (0.5-3.5 Hz) responses of healthy controls were higher than either de-novo AD or medicated AD group, without a difference between two AD subgroups. Furthermore, the auditory EO after presentation of tone bursts yielded no group difference. Conclusion: Our findings imply that delta ERO is highly unstable in AD patients in comparison to age-matched healthy controls only during the cognitive paradigm. Our results favor the hypothesis that neural delta networks are activated during cognitive tasks and that the reduced delta response is a general phenomenon in AD, due to cognitive impairment.
- PublicationMetadata onlyAuditory event-related delta oscillatory responses are reduced and delayed in patients with mild cognitive impairment(2012-09) Kurt, Pınar; Emek Savaş, Derya Durusu; Yener, Görsev; Güntekin, Bahar; Başar, Erol; 24351; 227002; 143760; 204666; 142226
- PublicationMetadata onlyAuditory Event-Related Delta Oscillatory Responses are Reduced in Patients with Mild Cognitive Impairment(Elsevier Science Inc, 360 Park Ave South, New York, Ny 10010-1710 Usa, 2012-04-15) Kurt, Pınar; Emek Savaş, Derya Durusu; Batum, Kübra; Turp Gölbaşı, Bilge; Güntekin, Bahar; Karşıdağ, Sibel; Başar, Erol; Yener, Görsev; 24351; 227002; 142090; 204666; 9297; 142226; 143760
- PublicationMetadata onlyBergson's Intuition and Memory in View of NeuroQuantology(Anka Publısher, 116-11 Sok No.10 K 2 D 2, Bornova, Izmir 35050, Turkey, 2009) Başar, Erol; Güntekin, Bahar; TR142226; TR204666This essay describes the concept of great philosopher Henri Bergson, related to episodic memory, intuition and duration. Further, the relation of "quantum theory" to Bergson's philosophy is shortly described. We discuss the importance of Bergson's concepts to "Quantum Methodology" and modern science.