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Abnormal 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
Best method for analysis of brain oscillations in healthy subjects and neuropsychiatric diseases
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-05) Turp Gölbaşı, Bilge; Tülay, Elif; Aydın, Serap; Başar Eroğlu, Canan; BAŞAR, EROL; 142226; 17772
The research related to brain oscillations and their connectivity is in a new take-off trend including the applications in neuropsychiatric diseases. What is the best strategy to learn about functional correlation of oscillations? In this report, we emphasize combined application of several analytical methods as power spectra, adaptive filtering of Event Related Potentials, inter-trial coherence and spatial coherence. These combined analysis procedure gives the most profound approach to understanding of EEG responses. Examples from healthy subjects, Alzheimer's Diseases, schizophrenia, and Bipolar Disorder are described. (C) 2016 The Authors. Published by Elsevier B.V.
Brain oscillations detect well-known brand perception in multiple gamma frequency bands
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-10) BAŞAR, EROL; 142226
Brain's beta response is strongly enhanced upon negative emotion eliciting stimuli
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2010-09) Güntekin, Bahar; Elif, Tülay; Turp, Bilge; BAŞAR, EROL; 204666; 142226
Decrease of delta oscillatory responses is associated with increased age in healthy elderly
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-05) Emek Savaş, Derya Durusu; Güntekin, Bahar; Yener, Görsev G.; BAŞAR, EROL; 204666; 143760; 142226
Background: The purpose of this study was to investigate changes in delta event-related oscillations (EROs) in younger and older healthy elderly subjects. We hypothesized that delta EROs were affected by age-related changes, which could be reflected in a visual oddball paradigm. Method: The study included two groups of subjects, 17 younger healthy elderly (mean age: 63.1 +/- 2.8 years) and 17 gender- and education-matched older healthy elderly (mean age: 79.6 +/- 5.2 years), who performed a visual oddball paradigm. EEG was recorded from F-3, F-z, F-4, C-3, C-z, C-4, P-3, P-z, P-4, O-1, O-z and O-2 locations. Peak-to-peak amplitudes of delta (0.5-3 Hz) target ERO responses during the post-stimulus 0-800 ms time window were measured. Repeated measures of ANOVA was used to analyze four locations (frontal, central, parietal, occipital), at three sagittal (left, midline, right) sites. Independent t-tests were applied for post-hoc analyses. Results: The older healthy elderly group had 16-25% lower values for the maximum peak-to-peak amplitudes of delta ERO compared with the younger healthy elderly group over frontal (p < 0.003), central (p < 0.0001) and parietal (p < 0.007) locations [F-3.95 = 4396, p = 0.015] Furthermore, there was a moderate negative correlation between age and C-z peak-to-peak amplitude of target delta responses [r = -0.401, p < 0.02], indicating the notion that peak-to-peak amplitude of C-z decreases as age increases. Conclusion: In the present study younger healthy elderly showed significantly higher event-related delta responses than older healthy elderly at frontal, central and parietal locations. Moreover, delta ERO responses decreased in accordance with age. (C) 2015 Elsevier B.V. All rights reserved.
Decrease of long distance event related gamma coherence in bipolar patients
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2010-09) Özerdem, Ayşegül; Güntekin, Bahar; Atagün, Murat İlhan; Turp, Bilge; Oral, Esat Timuçin; BAŞAR, EROL; 140995; 204666; 25145; 22231; 142226
Delta and theta oscillatory activity in aging
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-10) Yener, Görsev G.; 143760
Delta oscillatory responses as a general electrophysiological biomarker for cognitive disorders
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-10) Güntekin, Bahar; Hanoğlu, Lütfü; Aktürk, Tuba; Dilan, Güner; Turp Gölbaşı, Bilge; Yener, Görsev G.; BAŞAR, EROL; 204666; 171122; 275116; 143760; 142226
Enhanced event-related delta and theta response coherence upon cognitive stimulation
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2010-09) Güntekin, Bahar; BAŞAR, EROL; 204666; 142226
Event related oscillations triggered by the face of the loved person
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2008-09) Schmiedt Fehr, C.; Öniz, Adile; Başar Eroğlu, Canan; BAŞAR, EROL; 142226; 59951
Evoked coherence in Alzheimer disease
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2008-09) Güntekin, Bahar; Saatçı, Ertuğrul; Yener, Görsev G.; BAŞAR, EROL; 204666; 10488; 143760; 142226
Frontal delta event-related oscillations relate to frontal volume in mild cognitive impairment and healthy controls
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-05) Yener, Görsev G.; Emek Savaş, Derya Durusu; Lizio, Roberta; Çavuşoğlu, Berrin; Carducci, Filippo; Adem, Emel; Güntekin, Bahar; Babiloni, Claudio C.; BAŞAR, EROL; 143760; 204666; 142226
Amnesic mild cognitive impairment (MCI) represents a risk of developing Alzheimer's disease (AD), but not all MCI subjects progress to dementia of AD type. Magnetic resonance imaging (MRI) of cortical and hippocampal atrophy supports early diagnosis of AD in MCI subjects, while frontal event-related oscillations (EROS) at delta frequencies (<4 Hz) are appealing markers for this purpose, as they are both cost-effective and largely available. The present study tested the hypothesis that these EROs reflect cortical frontal neurodegeneration in the continuum between normal and amnesic MCI subjects. EROs and volumetric MRI data were recorded in 28 amnesic MCI and in 28 healthy elderly controls (HCs). EROs were collected during a standard visual oddball paradigm including frequent (66.6%) and rare (33.3%; targets to be mentally counted) stimuli. Peak-to-peak amplitude of delta target EROs (<4 Hz) was measured. Volume of frontal cortex was estimated from MRIs. Frontal volume was lower in MCI compared to the HC group. Furthermore, widespread delta target EROs were lower in amplitude in the former than in the latter group. Finally, there was a positive correlation between frontal volume and frontal delta target EROs in MCI and HC subjects as a whole group. These results suggest that frontal delta EROs reflect frontal neurodegeneration in the continuum between normal and amnesic MCI subjects. (C) 2015 Published by Elsevier B.V.
How is the brain working? Research on brain oscillations and connectivities in a new "Take-Off" state
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-05) Düzgün, Aysel; BAŞAR, EROL; 142226
The present report is a trial to survey analysis and applications of brain oscillations in cognitive impairment for opening the way to a new take off in research on brain oscillation. Although the number of papers related to brain oscillations rapidly increases, it is important to indicate the common principles governing the functioning of brain oscillations in the brain and body. Research scientists need a global view on the types of analysis, applications and existing oscillations. Further, scientists dealing with brain oscillations must have some knowledge from theoretical physics, system theory, and also general philosophy. The neuroscientists working on brain oscillations can mentally integrate several papers in the present report, and try to discover new avenues to augment knowledge on brain functions. A new take off in the search of brain oscillations indicates the strong need to survey this brunch of neuroscience in a broad panoply of science. (C) 2016 The Authors. Published by Elsevier B.V.
Lithium excessively enhances event related beta oscillations in patients with bipolar disorder
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2015-01-01) Atagün, Murat İlhan; Güntekin, Bahar; Tan, Devran; Tülay, Emine Elif; BAŞAR, EROL; 25145; 204666; 103606; 142226
Background: Previous resting-state electroencephalography studies have consistently shown that lithium enhances delta and theta oscillations in default mode networks. Cognitive task based networks differ horn resting-state networks and this is the first study to investigate effects or lithium on evoked and event-related beta oscillatory responses of patients with bipolar disorder. Methods: The study included 16 euthymic patients with bipolar disorder on lithium monotherapy, 22 euthymic medication-free patients with bipolar disorder and 21 healthy participants. The maximum peak-to-peak amplitudes were measured for each subject's averaged beta responses (14-28 Hz) in the 0-300 ms time window. Auditory simple and oddball paradigm were presented to obtain evoked and event-related beta oscillatory responses. Results: There were significant differences in beta oscillatory responses between groups (p=0.010). Repeated measures ANOVA revealed location (p=0.007), laterality X group (p=0.043) and stimulus X location (p=0.013) type effects. Serum lithium levels were correlated with beta responses. Limitations: The lithium group had higher number of previous episodes, suggesting that patients of the lithium were more severe cases than patients of the medication-free group. Discussion: Lithium stimulates neuroplastic cascades and beta oscillations become prominent during neuroplastic changes. Excessively enhanced beta oscillatory responses in the lithium-treated patients may be indicative of excessive activation of the neuron groups of the certain cognitive networks and dysfunctional GABAergic modulation during cognitive activity. (C) 2014 Elsevier B.V. All rights reserved.
Mindful brain and EEG-neurophysiology Preface
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-05) Güntekin, Bahar; Yener, Görsev G.; Başar Eroğlu, Canan; BAŞAR, EROL; 142226; 204666; 143760
Multiple functions of alpha activity in various areas of neuroscience
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2008-09) Güntekin, Bahar; BAŞAR, EROL; 142226; 204666
Multiple gamma oscillations enlighten communication pathways in brain areas for a well-known brand perception
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-10) BAŞAR, EROL; 142226
Resting state Rolandic mu rhythms are related to activity of sympathetic component of autonomic nervous system in healthy humans
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-05) Triggiani, Antonio Ivano; Valenzano, Anna; Del Percio, Claudio; Marzano, Nicola; Soricelli, Andrea; Petito, Annamaria; Bellomo, Antonello; Mundi, Ciro; Cibelli, Giuseppe; Babiloni, Claudio; BAŞAR, EROL; 142226
We tested the hypothesis of a relationship between heart rate variability (HRV) and Rolandic mu rhythms in relaxed condition of resting state. Resting state eyes-closed electroencephalographic (EEG) and electrocardiographic (ECG) data were recorded (10-20 System) in 42 healthy adults. EEG rhythms of interest were high frequency alpha (10.5-13 Hz) and low-frequency beta (13-20 Hz), which are supposed to form Rolandic mu rhythms. Rolandic and occipital (control) EEG sources were estimated by LORETA software. Results showed a statistically significant (p < 0.05, corrected) negative correlation across all subjects between Rolandic cortical sources of low-frequency beta rhythms and the low-frequency band power (LF, 0.04-0.15 Hz) of tachogram spectrum as an index of HRV. The lower the amplitude of Rolandic sources of low-frequency beta rhythms (as a putative sign of activity of somatomotor cortex), the higher the LF band power of tachogram spectrum (as a putative sign of sympathetic activity). This effect was specific as there was neither a similar correlation between these EEG rhythms and high-frequency band power of tachogram spectrum (as a putative sign of parasympathetic vagal activity) neither between occipital sources of low-frequency beta rhythms (as a putative sign of activity of visual cortex) and LF band power of tachogram spectrum. These results suggest that Rolandic low frequency beta rhythms are related to sympathetic activity regulating heart rate, as a dynamic neurophysiologic oscillatory mechanism sub-serving the interaction between brain neural populations involved in somatomotor control and brain neural populations regulating ANS signals to heart for on-going homeostatic adaptations. (C) 2015 Elsevier B.V. All rights reserved.
Review of evoked and event-related delta responses in the human brain
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2016-05) Güntekin, Bahar; BAŞAR, EROL; 204666; 142226
In the last decade, the brain's oscillatory responses have invaded the literature. The studies on delta (0.5-3.5 Hz) oscillatory responses in humans upon application of cognitive paradigms showed that delta oscillations are related to cognitive processes, mainly in decision making and attentional processes. The present manuscript comprehensively reviews the studies on delta oscillatory responses upon cognitive stimulation in healthy subjects and in different pathologies, namely Alzheimer's disease, Mild Cognitive Impairment (MCI), bipolar disorder, schizophrenia and alcoholism. Further delta oscillatory response upon presentation of faces, facial expressions, and affective pictures are reviewed. The relationship between pre-stimulus delta activity and post-stimulus evoked and event-related responses and/or oscillations is discussed. Cross-frequency couplings of delta oscillations with higher frequency windows are also included in the review. The conclusion of this review includes several important remarks, including that delta oscillatory responses are involved in cognitive and emotional processes. A decrease of delta oscillatory responses could be a general electrophysiological marker for cognitive dysfunction (Alzheimer's disease, MCI, bipolar disorder, schizophrenia and alcoholism). The pre-stimulus activity (phase or amplitude changes in delta activity) has an effect on post stimulus EEG responses. (C) 2016 The Authors. Published by Elsevier B.V.
Significant decrease of EEG alpha activity and visual-evoked alpha response in bipolar patients
(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2010-09) Güntekin, Bahar; Atagün, Murat İlhan; Tülay, Elif; Özerdem, Ayşegül; BAŞAR, EROL; Erol Başar 142226; 204666; 25145; 140995

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