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18th World Congress of Psychophysiology of the International Organization of Psychophysiology (IOP) -- AUG 31-SEP 04, 2016 -- Havana, CUBA WOS: 000382408700195 Background: In the last decade research on delta oscillatoryresponses invaded the literature. One of thefirst research on thisarea showed that delta responses increase upon cognitive load(Başar and Stampfer 1985). After this preliminary result, manyresearchers have shown that delta responses are related to attention,perception, decision making and working memory processes. Ourgroup and other groups in the literature indicated that the deltaresponses in different patient groups were decreased duringcognitive load in comparison to healthy controls. In a recent reviewwe have described that decrease of delta responses could be acandidate of a general electrophysiological biomarker for neuropsy-chiatric disorders (Güntekin and Başar 2015). Delta responses weredecreased in Alzheimer’s disease, in Mild Cognitive impairment(MCI) in bipolar disorder patients and as well as in schizophreniapatients during cognitive load in comparison to healthy controls. Inthe present study we analyze the delta responses in Parkinson’sdisease with and without cognitive deficits Int Org Psychophysiol

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.

Event-related oscillations (EROs) reflect cognitive brain dynamics, while sensory-evoked oscillations (SEOs) reflect sensory activities. Previous reports from our lab have shown that those with Alzheimer's disease (AD) or mild cognitive impairment (MCI) have decreased activity and/or coherence in delta, theta, alpha and beta cognitive responses. In the current study, we investigated gamma responses in visual SEO and ERO in 15 patients with AD and in 15 age-, gender- and education-matched healthy controls. The following parameters were analyzed over the parietal-occipital regions in both groups: (i) latency of the maximum gamma response over a 0–800 ms time window; (ii) the maximum peak-to-peak amplitudes for each participant's averaged SEO and ERO gamma responses in 3 frequency ranges (25–30, 30–35, 40–48 Hz); and (iii) the maximum peak-to-peak amplitudes for each participant's averaged SEO and ERO gamma responses over a 0–800 ms time block containing four divided time windows (0–200, 200–400, 400–600, and 600–800 ms). There were main group effects in terms of both latency and peak-to-peak amplitudes of gamma ERO. However, peak-to-peak gamma ERO amplitude differences became noticeable only when the time block was divided into four time windows. SEO amplitudes in the 25–30 Hz frequency range of the 0–200 ms time window over the left hemisphere were greater in the healthy controls than in those with AD. Gamma target ERO latency was delayed up to 138 ms in AD patients when compared to healthy controls. This finding may be an effect of lagged neural signaling in cognitive circuits, which is reflected by the delayed gamma responses in those with AD. Based on the results of this study, we propose that gamma responses should be examined in a more detailed fashion using multiple frequency and time windows., Highlights • Gamma responses elicited by sensory or cognitive stimulation were investigated. • Three frequency bands and four time windows were analyzed. • Alzheimer's disease (AD) patients and healthy controls were included in the study. • AD patients showed delayed cognitive gamma responses. • This delay was possibly due to lagged neural signals in cognitive circuits.

According to previous results, negative emotional facial expressions elicit oscillatory beta responses The present study analyzes event-related beta oscillations upon presentation of International Affective Picture System (IAPS) and aims to show whether behavior of beta in response to negative IAPS pictures also have similar dynamics IAPS pictures (unpleasant, pleasant, and neutral) were presented as a block and random passive viewing to 14 healthy subjects (8 male). Only with pictures with similar luminance level were selected as stimuli. Event-Related Potentials (ERPs) were recorded from 30 different scalp locations, and adaptive digital filtering was used for analysis in different frequency windows. The maximum peak-to-peak amplitudes were measured for each subject's averaged beta responses (15-30 Hz) in the 0 and 300 ms time window. Beta responses were significantly higher for unpleasant pictures than for pleasant and neutral pictures (average 50%). Beta responses were significantly higher for unpleasant than for pleasant pictures over frontal, central and parietal electrode sides (p < 0.05). Furthermore, beta responses were significantly higher for unpleasant than for neutral pictures over parietal and occipital electrodes (p < 0 04) In addition, the pleasant pictures elicited higher beta responses than neutral pictures over occipital electrode sites (p < 0 04) The results of the present study indicate that negative emotions are related to increased beta responses in humans, independent of stimulus types (facial expression or IAPS pictures) Accordingly, beta responses to negative emotions are possibly a common phenomenon The standardization of luminance in pictures may reduce divergences between results from different laboratories (C) 2010 Elsevier Ireland Ltd All rights reserved.

Background: GABA/Glutamatergic dysfunction and neural circuits which regulate cognitive processing are involved in the underlying pathology of bipolar disorder. Event related oscillatory neuroelectrical activity reflects integrative brain functioning, different frequency bands representing different cognitive functions. Methods: Event Related Potentials to visual odd-ball paradigm in ten manic/hypomanic medication free, DSM-IV bipolar patients were measured before and after six weeks of valproate monotherapy in comparison to ten sex and age matched healthy controls. Different frequency band responses were obtained by digital filtration of ERPs. Young mania rating scale (YMRS) was used to assess clinical response. Repeated measures ANOVA, Wilcoxon and Mann Whitney U tests were used for statistical analysis. Results: Patients showed significantly higher baseline occipital beta (1830 Hz) (p: 0.014) response than healthy controls. They were devoid of the occipito-frontal alpha (8-13 Hz) dominance presented by the control group. Occipital beta response reduced significantly (p: 0.009) and became similar to controls after treatment. Post-treatment alpha responses were significantly lower than baseline in anterior temporal (p: 0.038) and occipital (p: 0.027) locations. Healthy controls displayed a significantly increased frontal alpha response at the second assessment but the patients did not. Mean YMRS score reduced significantly compared to baseline at the end of six weeks (P: 0.004). Conclusions: Alpha response is the universal operator in the brain. Increased occipital beta response in mania may be compensatory to the dysfunctional alpha operation. its reduction after valproate may be through modulation of glutamatergic and GABAergic mechanisms and indicate medication's corrective effect on the underlying pathogenesis. (c) 2008 Elsevier B.V. All rights reserved.

There are only few studies describing gender differences in recognition of facial expressions. Our study has the aim to analyze the effect of gender differences in oscillatory brain responses. Three sets of Ekman and Friesens's facial expressions (neutral, angry, and happy) were presented to 26 healthy subjects (13 men) while recording from 13 different scalp locations. Occipital beta response (15-24 Hz) was significantly larger for women than for men during the presentation of face expressions. Our results demonstrate that processing of emotional face expressions clearly differs between men and women. Accordingly, the results indicate the necessity of introducing standardization between male and female subjects by means of oscillatory dynamics. In turn, this standardization may be useful for cognitive and clinical studies. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

There are few studies describing gender differences in event related oscillations (EROS). In the present report we demonstrate that gender differences are apparent in EROS even during simple visual stimulation, possibly activating very basic sensory networks. The data of 32 (16 males) healthy subjects were recorded from thirteen different scalp locations (F-3, F-4, C-z, C-3, C-4, T-3, T-4, T-5, T-6, P-3, P-4, O-1, O-2). Analysis was performed in the delta (0.5-3.5 Hz), theta (5-8.5 Hz), alpha (9-13 Hz), beta (15-24 Hz), and gamma (28-48 Hz) frequency ranges. The results showed that the maximum peak-to-peak delta response amplitudes for women were significantly higher than for men over occipital, parietal, central and temporal electrode locations. There were also differentiations in the beta and gamma oscillatory responses. These gender differences were most pronounced over the electrode Site O-2, that is, over primary visual areas. It is suggested that this study might serve as a standard to investigate gender differences in electrophysiology. (c) 2007 Elsevier B.V All rights reserved.

The 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 modern 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 modern 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.

This is a pilot study describing event-related oscillations in patients with Alzheimer-type dementia (AD). Theta responses of 22 mild probable AD subjects according to NINCDS-ADRDA criteria (11 non-treated, 11 treated by cholinesterase inhibitors), and 20 healthy elderly controls were analyzed by using the conventional visual oddball paradigm. We aimed to compare theta responses of the three groups in a range between 4-7 Hz at the frontal electrodes. At F-3 location, theta responses of healthy subjects were phase locked to stimulation and theta oscillatory responses of non-treated Alzheimer patients showed weaker phase-locking, i.e. average of Z-transformed means of correlation coefficients between single trials was closer to zero. In treated AD patients, phase-locking following target stimulation was two times higher in comparison to the responses of non-treated patients. The results indicate that the phase-locking of theta oscillations at F-3 in the treated patients is as strong as the control subjects. The F-4 theta responses were not statistically significant between the groups. Our findings imply that the theta responses at F3 location are highly unstable in comparison to F4 in non-treated mild AD patients and cholinergic agents may modulate event-related theta oscillatory activities in the frontal regions. (c) 2006 Elsevier B.V. All rights reserved.

18th World Congress of Psychophysiology of the International Organization of Psychophysiology (IOP) -- AUG 31-SEP 04, 2016 -- Havana, CUBA WOS: 000382408700070 … International Organization of Psychophysiology

Background CBD is a neurodegenerative disorder characterized by asymmetric motor parkinsonism symptomatology and impairment in language, personality and affective functions that are related to frontoparietal atrophy. To date, there is still no effective treatment for CBD. In this respect, TMS may be a novel therapeutic candidate for CBS. Considering all of this evidence, we aimed to evaluate the pre and post-treatment electrophysiological, neurometabolic and neuropsychometric correlates of TMS application in four CBS patients. Methods We have evaluated the pre and post treatment EEG, FDG-PET and detailed clinical behavioral and neuropsychometric test correlates of TMS in four CBD patients who were admitted to our dementia outpatient at the University of Medipol-Istanbul. The following detailed neuropsychometric test procedures were applied to patients; Digit Span (Forward/Back) Test, Verbal Fluency Test, Lexical Fluency Test, Clock Drawing Test, Similarities and Comprehension test, Verbal Learning Test (SBSTTA-Oktem), Wechsler Memory Scale (WMS-Logical Memory Test), Benton Face Recognition Test (BFR), Line Orientation Identification Test (BLOT), Neuropsychiatric Inventory (NPI), Geriatric Depression Scale (GDS), Frontal Behavioral Inventory Test (FBI), Standardized Mini Mental State Examination (MMSE) and Clinical Dementia Rating-Scale (CDR). Results & conclusion We have found that increased pretreatment theta activity was significantly decreased after the TMS treatment in frontal, central and parietal regions that was associated with the normalized glucose metabolism and neurobehavioral test scores after the TMS treatment.

try to identify central and peripheral markers related to emotional processes. Furthermore, the increased abilities of functional neural techniques have consistently favored the exploration of emotional components in health and in pathology. In this frame, the aim of this symposium is to bring together innovative researches integrating neurobehavioral data related to normal and dysregulated emotional reactivity. Consequently, the first (H. Sequeira, University of Lille, France) and second (B. Guntekin, Istanbul Kultur University, Turkey) speakers will illustrate the brain dynamic of affective pictures processing in healthy individuals by using magnetoencephalographic and oscillatory cerebral analyses. C. Baeken (Ghent University and University Hospital of Brussels, Belgium), through the application of repetitive Transcranial Magnetic Stimulation (rTMS), will show the potential importance of cingulate functional connectivity in treatment-resistant depression. J.M. Martinez-Selva (University of Murcia, Spain) will focus on the relevance of autonomic (the heart, electrodermal and respiratory activities) and somatic (corrugator supercilii activity) responses to understand mechanisms of neural and behavioral reactivity of persons with blood and snake phobia. J. Martineau (INSERM and University of Tours, France), thanks to behavioral (gaze patterns) and eye physiological indices (pupil diameter and blink rates), will show the interest of emotional static and dynamic faces analyses to explain the impaired social interaction in autistic pathology. In brief, by the original combination of psychophysiological tools in healthy and in behavioral disturbed individuals, this symposium will give an updated and prospective panorama of neurobehavioral exploration of emotion.

Mild Cognitive Impairment (MCI) is considered in many as prodromal stage of Alzheimer's disease (AD). Event-related oscillations (ERO) reflect cognitive responses of brain whereas sensory-evoked oscillations (SE) inform about sensory responses. For this study, we compared visual SEO and ERO responses in MCI to explore brain dynamics (Background). Forty-three patients with MCI (mean age=74.0 year) and 41 age- and education-matched healthy-elderly controls (HC) (mean age=71.1 year) participated in the study. The maximum peak-to-peak amplitudes for each subject's averaged delta response (0.5-3.0 Hz) were measured from two conditions (simple visual stimulation and classical visual oddball paradigm target stimulation) (Method). Overall, amplitudes of target ERO responses were higher than SEO amplitudes. The preferential location for maximum amplitude values was frontal lobe for ERO and occipital lobe for SEO. The ANOVA for delta responses showed significant results for the group Xparadigm. Post-hoc tests indicated that (1) the difference between groups were significant for target delta responses, but not for SEO, (2) ERO elicited higher responses for HC than MCI patients, and (3) females had higher target ERO than males and this difference was pronounced in the control group (Results). Overall, cognitive responses display almost double the amplitudes of sensory responses over frontal regions. The topography of oscillatory responses differs depending on stimuli: visualsensory responses are highest over occipitals and -cognitive responses over frontal regions. A group effect is observed in MCI indicating that visual sensory and cognitive circuits behave differently indicating preserved visual sensory responses, but decreased cognitive responses (Conclusion). (C) 2014 Elsevier B.V. All rights reserved.

WOS: 000373081100001, PubMed ID: 25465436, The effect of lithium on neurocognition is not still fully explored. Brain oscillatory activity is altered in bipolar disorder. We aimed to assess the oscillatory responses of euthymic bipolar patients and how they are affected by lithium monotherapy. Event-related oscillations in response to visual target stimulus during an oddball paradigm in 16 euthymic drug-free and 13 euthymic lithium-treated bipolar patients were compared with 16 healthy controls. The maximum peak-to-peak amplitudes were measured for each subject's averaged beta (15-30 Hz) responses in the 0- to 300-ms time window over frontal (F3, Fz, F4), central (C3, Cz, C4), temporal (T7, T8), temporo-parietal (TP7, TP8), parietal (P3, Pz, P4), and occipital (O1, Oz, O2) areas. Patients under lithium monotherapy had significantly higher beta responses to visual target stimuli than healthy controls (P = .017) and drug-free patients (P = .015). The increase in beta response was observed at all electrode locations, however, the difference was statistically significant for the left (T7; P = .016) and right (T8; P = .031) temporal beta responses. Increased beta responses in drug-free patients and further significant increase in lithium-treated patients may be indicative of a core pathophysiological process of bipolar disorder and how it is affected by lithium. Whether the finding corresponds to lithium's corrective effect on the underlying pathology or to its neurocognitive side effect remains to be further explored. In either case, the finding is a sign that the oscillatory activity may be useful in tracking medication effect in bipolar disorder., Mental Health/Developmental Disabilities Research Award at Children's Hospital, Boston (NIH HHS/United States) [43TW05807/TW/FIC], The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was supported by the Mental Health/Developmental Disabilities Research Award at the Children's Hospital, Boston (43TW05807/TW/FIC NIH HHS/United States, Dr Kerim Munir, Principal Investigator).

Since 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.

WOS: 000344226700010, PubMed ID: 25233240, 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., Istanbul Kultur University; Bakirkoy Research and Training Hospital, Istanbul Kultur University has funded and Bakirkoy Research and Training Hospital has supported the study.

WOS: 000333848200001, PubMed ID: 24825953, Background. Event-related oscillations (ERO) may provide a useful tool for the identification of cognitive deficits in mild cognitive impairment (MCI) and Alzheimer's disease (AD). In the present study, we investigate peak-to-peak amplitude of auditory eventrelated delta oscillations of MCI subjects. Method. The study included twenty-two consecutive patients with MCI recruited in neurology clinic and 21 age-and education-matched normal elderly controls. A classical auditory oddball paradigm was used in the experiments. 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. The maximum peak-to-peak amplitudes for each subject's averaged delta response (0.5-2.2Hz) weremeasured. Results. The amplitudes between groups differed significantly at the frontal and mid-centroparietal locations. ANOVA on delta responses revealed a significant effect for groups (F-(1.41) = 4.84, P = 0.033), indicating a larger delta response for healthy controls thanMCI subjects. Post hoc comparisons revealed that peak-to-peak delta response was significantly larger for healthy controls than for MCI over electrode sites F-3, F-z, F-4, C-z, C-4, and Pz. Discussion. Event-related delta frequency band seems to be the most affected oscillatory response in cognitive impairment due to AD. Therefore, it deserves to be investigated as a candidate electrophysiological biomarker in further studies., Scientific and Technological Research Council of Turkey [112S459], This study has been founded by the Scientific and Technological Research Council of Turkey (Project no. 112S459).

Decreased delta oscillation upon cognitive load is common in patients with Alzheimer׳s disease, mild cognitive impairment, and schizophrenia. However, there is no previous study analyzing the delta responses in euthymic medication-free patients with bipolar disorder. Participants comprised of 22 euthymic medication-free patients with DSM-IV diagnoses of bipolar disorder and 21 healthy controls who were matched to the patients for sex, age, and education. Electroencephalographic activity was recorded at 30 electrode sites using an application of an auditory oddball paradigm. The maximum peak-to-peak amplitudes for each subject׳s averaged delta response (0.5-3.5Hz) were measured. There was a significant inter-group difference in evoked and event-related delta (0.5-3.5Hz) responses. Post-hoc comparisons revealed that the event-related delta oscillatory responses of the bipolar patient group were significantly lower than those of the healthy control group over the temporo-parietal and occipital electrode sites. Euthymic bipolar patients showed reduced event-related delta oscillatory responses in comparison to healthy subjects under cognitive load. The decrease of delta oscillations may be a common phenomenon that can be observed in different neuropsychiatric disorders with cognitive dysfunction.

Method and concepts of brain oscillations pervade the neuroscience literature, especially in cognitive processes. Electrophysiological changes in patients with cognitive impairment will provide fundamental knowledge, not only for clinical studies but also, in turn, for understanding cognitive processes in healthy subjects. This review includes description of brain oscillations in schizophrenia, bipolar disorder, mild cognitive impairment, Alzheimer's disease, and attention deficit hyperactivity disorder. The reviewed publications include several methodological approaches: analysis of spontaneous electroencephalogram (EEG) spectra, evoked oscillations, event-related oscillations, and coherences both in spontaneous EEG and event-related oscillations. The review clearly shows that, in cognitive impairment, fundamental changes are observed in all diseases under study. Accordingly, oscillations can most probably be used as biomarkers in clinical studies. The conclusions of this review include several remarks indicating the nature of brain oscillations, their application to cognitive processes, and the usefulness of recording brain oscillations in memory loss, attention deficit, and learning.

Brain oscillations have gained tremendous importance in neuroscience during recent decades as functional building blocks of sensory-cognitive processes. Research also shows that event-related oscillations (EROs) in "alpha," "beta," "gamma," "delta," and "theta" frequency windows are highly modified in pathological brains, especially in patients with cognitive impairment. The strategies and methods applied in the present report reflect the innate organization of the brain: "the whole brain work." The present paper is an account of methods such as evoked/event-related spectra, evoked/ERDs, coherence analysis, and phase-locking. The report does not aim to cover all strategies related to the systems theory applied in brain research literature. However, the essential methods and concepts are applied in several examples from Alzheimer's disease (AD), schizophrenia, and bipolar disorder (BD), and such examples lead to fundamental statements in the search for neurophysiological biomarkers in cognitive impairment. An overview of the results clearly demonstrates that it is obligatory to apply the method of oscillations in multiple electroencephalogram frequency windows in search of functional biomarkers and to detect the effects of drug applications. Again, according to the summary of results in AD patients and BD patients, multiple oscillations and selectively distributed recordings must be analyzed and should include multiple locations. Selective connectivity between selectively distributed neural networks has to be computed by means of spatial coherence. Therefore, by designing a strategy for diagnostics, the differential diagnostics, and application of (preventive) drugs, neurophysiological information should be analyzed within a framework including multiple methods and multiple frequency bands. The application of drugs/neurotransmitters gains a new impact with the analysis of oscillations and coherences. A more clear and differentiated analysis of drug effects can be attained in comparison to the application of the conventional wide-band evoked potential and event-related potential applications.

Kurt, Pınar (Arel Author) --- #nofulltext#, Mild cognitive impairment (MCI) is considered as a prodromal stage for Alzheimer's disease (AD) in the majority of cases. Event-related oscillations might be used for detection of cognitive deficits. Our group's earlier results showed diminished delta visual and auditory target oscillatory responses in AD, and we investigated whether this prevails for MCI. Eighteen MCI subjects and 18 age-matched healthy elderly controls were investigated. The maximum peak-to-peak amplitudes of oscillatory responses for each subject's averaged oscillatory target responses in delta, theta, and alpha frequency bands upon application of visual oddball paradigm were measured. Repeated measures of ANOVA was used to analyze four locations (frontal, central, parietal, occipital), at three coronal (left, midline, right) sites. Independent t tests were applied for post-hoc analyses. The oddball target delta response (0.5-3.0 Hz) was 26-32% lower in MCI than healthy controls over fronto-central-parietal regions [F(1.34) = 4.562, p = 0.04]. Without a group effect, theta oscillatory responses (4-7 Hz) showed significant differences in coronal electrodes indicating highest values over mid-electrode sites, and a anteriorposterior x coronal effect, being maximum at mid-central. Alpha frequency band analyses indicated no statistical differences. Peak-to-peak amplitudes of visual target delta oscillatory responses were lower in fronto-central-parietal regions in MCI than in healthy controls. This supports our earlier findings in AD, showing hypoactive delta fronto-central-parietal regions during cognitive tasks. These results indicate that event-related oscillations may detect early changes of brain dynamics in MCI, and deserves to be investigated as a candidate biomarker in further studies using multimodal techniques.

Method and concepts of brain oscillations pervade the neuroscience literature, especially in cognitive processes. Electrophysiological changes in patients with cognitive impairment will provide fundamental knowledge, not only for clinical studies but also, in turn, for understanding cognitive processes in healthy subjects. This review includes description of brain oscillations in schizophrenia, bipolar disorder, mild cognitive impairment, Alzheimer's disease, and attention deficit hyperactivity disorder. The reviewed publications include several methodological approaches: analysis of spontaneous electroencephalogram (EEG) spectra, evoked oscillations, event-related oscillations, and coherences both in spontaneous EEG and event-related oscillations. The review clearly shows that, in cognitive impairment, fundamental changes are observed in all diseases under study. Accordingly, oscillations can most probably be used as biomarkers in clinical studies. The conclusions of this review include several remarks indicating the nature of brain oscillations, their application to cognitive processes, and the usefulness of recording brain oscillations in memory loss, attention deficit, and learning.

Brain oscillations have gained tremendous importance in neuroscience during recent decades as functional building blocks of sensory-cognitive processes. Research also shows that event-related oscillations (EROs) in "alpha," "beta," "gamma," "delta," and "theta" frequency windows are highly modified in pathological brains, especially in patients with cognitive impairment. The strategies and methods applied in the present report reflect the innate organization of the brain: "the whole brain work." The present paper is an account of methods such as evoked/event-related spectra, evoked/ERDs, coherence analysis, and phase-locking. The report does not aim to cover all strategies related to the systems theory applied in brain research literature. However, the essential methods and concepts are applied in several examples from Alzheimer's disease (AD), schizophrenia, and bipolar disorder (BD), and such examples lead to fundamental statements in the search for neurophysiological biomarkers in cognitive impairment. An overview of the results clearly demonstrates that it is obligatory to apply the method of oscillations in multiple electroencephalogram frequency windows in search of functional biomarkers and to detect the effects of drug applications. Again, according to the summary of results in AD patients and BD patients, multiple oscillations and selectively distributed recordings must be analyzed and should include multiple locations. Selective connectivity between selectively distributed neural networks has to be computed by means of spatial coherence. Therefore, by designing a strategy for diagnostics, the differential diagnostics, and application of (preventive) drugs, neurophysiological information should be analyzed within a framework including multiple methods and multiple frequency bands. The application of drugs/neurotransmitters gains a new impact with the analysis of oscillations and coherences. A more clear and differentiated analysis of drug effects can be attained in comparison to the application of the conventional wide-band evoked potential and event-related potential applications.

Objective Decreased delta event-related oscillations (ERO) have been reported in prior studies of Alzheimer’s disease (AD) and mild cognitive impairment (MCI); however no study has examined its utility in predicting disease progression. In this study, we examined the longitudinal changes in brain dynamics of MCI by using delta ERO and volumetric MRI (vMRI). Methods Twenty-two MCI and 23 matched control subjects were included. Peak-to-peak amplitudes of delta (0.5–3.5 Hz) auditory target ERO and vMRI were measured at baseline and a year later. The ERO and vMRI of stable and progressive MCI were compared. Results Decreased amplitudes of delta ERO were found in MCI for baseline and follow-up [F1.43 = 11.394, p = 0.002]. Progressive MCI had lower delta ERO than stable MCI at F3 electrode site at baseline. vMRI revealed that MCI had lower volumes at baseline in whole brain and left hippocampus, and at follow-up in whole brain, right and left hippocampi. Moreover, a moderate correlation was found between left hippocampus volumes and delta ERO at C4 electrode site. Conclusions These findings indicate that delta ERO may detect early changes in MCI and can be a useful tool to predict disease progression. Brain oscillatory responses have the potential to be used as biomarker in MCI.

Objective Parkinson’s disease (PD) is the second most common progressive neurodegenerative disorder which affects both motor and cognitive functioning. This study aims to investigate the sensory evoked oscillations (SEO) and event-related oscillations (ERO) of visual modality in cognitively normal PD patients and healthy controls. Methods Sixteen PD and 16 matched control subjects were participated to the study. Simple flashlight was used for SEO and a classical visual oddball paradigm was used for target ERO. Oscillatory responses in delta frequency range (0.5–3.0 Hz) were examined. Results Significant differences were found between groups on the maximum peak-to-peak amplitudes of both delta ERO and SEO responses [ F 1.27 = 8.573, p = 0.007; F 1.27 = 6.306, p = 0.018, respectively], indicating significantly lower delta responses in PD than healthy controls. Delta ERO responses were decreased in PD in frontal, central and parietal locations ( p Conclusions In this study, both target delta ERO and SEO responses were decreased in PD. According to the notion that the activity of sensory networks are reflected by SEO and cognitive networks by ERO, these findings indicate that PD patients have impairments in both networks of visual modality. Brain oscillatory responses have a potential to be searched as a biomarker for visual cognitive and sensory status of PD.

Aim 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

Brain's alpha activity and alpha responses belong to major electrical signals that are related to sensory/cognitive signal processing. The present study aims to analyze the spontaneous alpha activity and visual evoked alpha response in drug free euthymic bipolar patients. Eighteen DSM-IV euthymic bipolar patients (bipolar I n = 15, bipolar II n = 3) and 18 healthy controls were enrolled in the study. Patients needed to be euthymic at least for 4 weeks and psychotrop free for at least 2 weeks. Spontaneous EEG (4 min eyes closed, 4 min eyes open) and evoked alpha response upon application of simple visual stimuli were analyzed. EEG was recorded at 30 positions. The digital FFT-based power spectrum analysis was performed for spontaneous eyes closed and eyes open conditions and the response power spectrum was also analyzed for simple visual stimuli. In the analysis of spontaneous EEG, the ANOVA on alpha responses revealed significant results for groups (F(1,34) = 8.703; P < 0.007). Post-hoc comparisons showed that spontaneous EEG alpha power of healthy subjects was significantly higher than the spontaneous EEG alpha power of euthymic patients. Furthermore, visual evoked alpha power of healthy subjects was significantly higher than visual evoked alpha power of euthymic patients (F(1,34) = 4.981; P < 0.04). Decreased alpha activity in spontaneous EEG is an important pathological EEG finding in euthymic bipolar patients. Together with an evident decrease in evoked alpha responses, the findings may lead to a new pathway in search of biological correlates of cognitive impairment in bipolar disorder.

Background: EEG coherence represents the brain's functional connectivity. Synchronous neural gamma oscillations are critical for cortico-cortical communication and large-scale integration of distributed sets of neurons. We investigated long distance gamma (28-48 Hz) coherence in bipolar disorder. Methods: Sensory evoked coherence (EC) and event related coherence (ERC) values for the gamma frequency band during simple light stimulation and visual odd-ball paradigm was assessed in 20 drug-free euthymic bipolar patients in comparison to healthy controls. Groups were compared for the coherence values of the left (F(3)-T(3), F(3)-TP(2), F(3)-P(3), F(3)-O(1)) and right (F(4)-T(4), F(4)-TP(8), F(4)-P(4), F(4)-O(2)) intra-hemispheric electrode pairs by means of a repeated measure analysis of variance (ANOVA) and t-tests. Results: Patients showed significantly lower gamma coherence values in response to target stimuli than the healthy controls between left and right fronto-temporal, as well as between frontal and temporo-parietal electrode pairs. Coherence values for the non-target stimuli were significantly lower in the patients than the healthy controls between frontal and temporo-parietal regions on both right and left sides. EP coherence values did not differ significantly between the groups. Limitations: A relatively small sample size is the major limitation of the study. Conclusions: Bipolar patients present disturbance in functional long-range connectivity between the frontal and temporal as well as temporo-parietal brain structures during a cognitive paradigm requiring attention and immediate recall. The location of the connectivity disturbance corresponds to the underlying neurobiology of executive function, memory and attention impairments in bipolar disorder and raises the question of whether gamma coherence reduction may be a candidate biomarker for bipolar disorder. (C) 2011 Elsevier B.V. All rights reserved.

In previous studies on Alzheimer's patients it was shown that, in frontal and parietal locations, delta and theta responses of AD patients were greatly reduced. The present study analyzed coherence functions in these highly affected frontal and parietal areas. Visual sensory and event related coherences of patients with Alzheimer type dementia (AD) were analyzed comparatively. A total of 38 mild, probable AD subjects (19 untreated, 19 treated with cholinesterase inhibitors) were compared with a group of 19 healthy controls. The sensory evoked coherence and event related target coherences were analyzed for delta (1-3.5 Hz), theta (4-7 Hz), alpha (8-13 Hz), beta (15-30 Hz) and gamma (28-48 Hz) frequency ranges for long-range intra-hemispheric (F-3-P-3, F-4-P-4, F-3-T-5, F-4-T-6, F-3-O-1, F-4-O-2) electrode pairs. The healthy control group showed significantly higher values of event related coherence in "delta", "theta" and "alpha" bands in comparison to the de nova and medicated AD groups (p

oscillatory activity, signifies the functional coupling of distributed brain regions involved in reward processing. Also, this provides support for the notion that two dissociable neural networks can be delineated for the processing of gains and losses (Yacubian et al., 2006). Based on the result that there was no effect of outcome probability on the thetaand beta-oscillations accordingly suggests that these oscillatory activities also may reflect an evaluation of outcomes on a shorter time scale in the learning process.

The aim of this study was to investigate long distance event-related gamma (28-48 Hz) coherence in mania before and after valproate monotherapy. Gamma coherence in response to visual oddball paradigm in ten medication-free, manic patients was studied before and after six weeks of valproate monotherapy in comparison to ten controls. Inter-hemispheric F(3)-F(4), C(3)-C(4), T(3)-T(4), T(5)-T(6), P(3)-P(4), O(1)-O(2) and intra-hemispheric F(3)-P(3), F(4)-P(4), F(3)-T(5), F(4)-T(6), F(3)-O(1), F(4)-O(2), C(3)-O(1), C(2)-O(4) electrode pairs were included in the analysis. Repeated measures ANOVA revealed a significant difference between groups with regard to pre-treatment coherence values (p: 0.018). The coherence to the target stimuli at the right fronto-temporal location was significantly reduced by 35.41% in the patients compared to controls (p: 0.003). Patients showed significantly lower pretreatment coherence values in response to non-target stimuli compared to controls at the right frontotemporal (28.51%, p: 0.004), right fronto-occipital (23.71%, p: 0.024), and right centro-occipital (25.69%, p: 0.029) locations. After six weeks of valproate monotherapy, manic symptoms improved significantly. Post-treatment change in target and non-target coherence values was statistically non-significant. EEG coherence is a measure of functional connectivity in the brain. Event-related gamma oscillations are essential for brain electrical activity. The results show that acute mania presents right sided long distance connectivity disturbance, thus pointing to the potential importance of measuring oscillatory responses in the search for consistent neurobiological markers in such a complicated condition as bipolar disorder. (C) 2010 Elsevier Inc. All rights reserved.

Previous 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.

Charles 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.

This 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.

We 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.

The present study describes electrophysiological differentiation of "Facial Expressions" by using the method of event-related oscillations (EROS). These measures were used to assess electrical manifestations of emotional expressions of 20 healthy subjects exposed to neutral, angry, and happy" faces. The present study extended previous analysis to frequency windows of delta (0.5-3.5 Hz) and theta (5-8.5 Hz) oscillations. No significant differences among responses to various face expression stimuli were observed, however, topological differences in response to all facial expressions were found. Delta oscillatory responses in the parietal-temporal-occipital locations were larger than the frontal and central locations, whereas theta oscillatory responses in the right temporal-occipital electrodes were larger than the right central electrodes. Assessment of topologically distributed multiple oscillations opens a new avenue for understanding of the electrophysiology of recognition of "faces" and "facial expressions". (c) 2008 Elsevier B.V. All rights reserved.

This 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.

Charles 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.

The 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.

In this study event related coherence of patients with Alzheimer type of dementia (AD) was analyzed by using a visual oddball paradigm as stimuli. A total of 21 mild probable AD subjects (10 untreated, 11 treated) were compared with a group of 19 healthy controls. The members of the groups had their EEG recorded from 12 electrodes by means of a visual oddball paradigm. The evoked coherence was analyzed for delta (1-3.5 Hz), theta (4-7 Hz) and alpha (8-13 Hz) frequency ranges for inter-hemispheric (F(3)-F(4), C(3)-C(4), T(3)-T(4), T(5)-T(6), P(3)-P(4), O(1)-O(2)) and long range intra-hemi spheric (F(3)-P(3), F(4)-P(4), F(3)-T(5), F(4)-T(6), F(3)-O(1), F(4)-O(2)) electrode pairs. The control group showed higher values of evoked coherence in "delta", "theta" and "alpha" bands in the left fronto-parietal electrode pairs in comparison with the untreated AD group (p < 0.01 for all frequency bands). Furthermore, the control group showed higher values of evoked coherence in the left fronto-parietal electrode pair in theta frequency band (p < 0.01) and higher values of evoked coherence in the right fronto-parietal electrode pair in delta band (p < 0.01) when compared to treated AD group. The only significant difference between the treated and untreated AD groups was in the alpha band. The treated AD group showed higher values of evoked coherence at the left fronto-parietal pair in alpha band in comparison to the untreated AD group (p < 0.01). During a working memory process the coherence in the left fronto-parietal electrode pair (F(3)-P(3)) of AD patients is significantly decreased, thus indicating reduced connectivity between frontal and parietal sites. (c) 2008 Elsevier B.V. All rights reserved.

Comparatively analyses of electrophysiological correlates across species during evolution, alpha activity during brain maturation, and alpha activity in complex cognitive processes are presented to illustrate a new multidimensional "Cartesian System" brain function. The main features are: (1) The growth of the alpha activity during evolution, increase of alpha during cognitive processes, and decrease of the alpha entropy during evolution provide an indicator for evolution of brain cognitive performance. (2) Human children younger than 3 years are unable to produce higher cognitive processes and do not show alpha activity till the age of 3 years. The mature brain can perform higher cognitive processes and demonstrates regular alpha activity. (3) Alpha activity also is significantly associated with highly complex cognitive processes, such as the recognition of facial expressions. The neural activity reflected by these brain oscillations can be considered as constituent "building blocks" for a great number of functions. An overarching statement on the alpha function is presented by extended analyzes with multiple dimensions that constitute a "Cartesian Hyperspace" as the basis for oscillatory function. Theoretical implications are considered.

Background and purpose: Alzheimer type of dementia (AD) is the most common neuropsychiatric morbidity in elderly individuals. Event-related oscillations (ERO) provide an useful tool for detecting subtle abnormalities of cognitive processes with high temporal resolution. Methods: In the present report, event-related oscillations of patients with AD were analyzed by using a visual oddball paradigm. A total of 22 mild probable AD subjects according to NINCDS-ADRDA criteria and 20 age-, gender-, and education-matched healthy control subjects were compared. AD group consisted from 11 untreated patients and 11 patients treated with cholinesterase inhibitor. Oscillatory responses were recorded from 13 scalp electrodes. Results: Significant differences in delta frequency range were seen between the groups by using repeated measures of ANOVA analysis [F(9.120) = 2.228; P = 0.022]. Post-hoc analyses using Wilcoxon test showed that at mid- and left central regions, (Cz, C3) peak amplitudes of delta responses of healthy subjects were significantly higher than either group. Also cholinesterase inhibitors did not have effect on delta oscillatory responses. Conclusions: Our findings imply that the delta oscillatory responses at central locations are highly instable in mild probable AD patients regardless of treatment when compared to the healthy aged controls. This study supports the importance of oscillatory event-related potentials for investigating AD brain dynamics.