Serap Aydin

Serap Aydin
Hacettepe University · School of Medicine

PhD. Professor (Associate)
I have studied on functional brain network measures in computational and behavioral neuro-science.

About

78
Publications
8,759
Reads
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633
Citations
Citations since 2016
41 Research Items
507 Citations
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
Introduction
My research interests are emotion/mood recognition, futuristic neuro-modelling in the field of behavioral/computational neuroscience. I have studied on neural networks and advanced processing/analysis of physiological recordings such as EEG, MEG and fNIRs to investigate neural mechanism underlying perception and cognition. ---- ---- https://loop.frontiersin.org/people/264086/overview
Education
March 1999 - September 2005
Middle East Technical University
Field of study
  • Biomedical Engineering (major) and Signal Processing (minor)

Publications

Publications (78)
Article
Full-text available
In the present study, both single channel electroencephalography (EEG) complexity and two channel interhemispheric dependency measurements have newly been examined for classification of patients with obsessive–compulsive disorder (OCD) and controls by using support vector machine classifiers. Three embedding entropy measurements (approximate entrop...
Article
In this study, 64-channel single trial auditory brain oscillations (STABO) have been firstly analyzed by using complexity metrics to observe the effect of musical experience on brain functions. Experimental data was recorded from eyes-opened volunteers during listening the musical chords by piano. Complexity estimation methods were compared to each...
Article
In the present article, a novel emotional complexity marker is proposed for classification of discrete emotions induced by affective video film clips. Principal Component Analysis (PCA) is applied to full-band specific phase space trajectory matrix (PSTM) extracted from short emotional EEG segment of 6 s, then the first principal component is used...
Article
Full-text available
In the present study, quantitative relations between Cognitive Emotion Regulation strategies (CERs) and EEG synchronization levels have been investigated for the first time. For this purpose, spectral coherence (COH), phase locking value and mutual information have been applied to short segments of 62-channel resting state eyes-opened EEG data coll...
Article
Resting-state brain networks represent the intrinsic state of the brain during the majority of cognitive and sensorimotor tasks. However, no study has yet presented concise predictors of task-induced vigilance variability from spectro-spatial features of the resting-state electroencephalograms (EEG). In this study, ten healthy volunteers have parti...
Article
In this study, cognitive and behavioral emotion regulation strategies (ERS) are classified by using machine learning models driven by a new local EEG complexity approach so called Frequency Specific Complexity (FSC) in resting-states (eyes-opened (EO), eyes-closed (EC)). According to international 10–20 electrode placement system, FSC is defined as...
Article
Full-text available
In the present study, new findings reveal the close association between graph theoretic global brain connectivity measures and cognitive abilities the ability to manage and regulate negative emotions in healthy adults. Functional brain connectivity measures have been estimated from both eyes-opened and eyes-closed resting-state EEG recordings in fo...
Article
The goal of the present study is to propose the use of global connectivity measures as quantitative indicators of long-term medication in pediatric patients with Attention-Deficit-Hyperactivity Disorder, combined type (ADHD-C). For this purpose, graph theoretical brain connectivity indices are computed from connectivity estimations across eyes-open...
Article
Full-text available
The present study shows new findings that reveal the high association between emotional arousal and neuro-functional brain connectivity measures. For this purpose, contrasting discrete emotional states (happiness vs sadness, amusement vs disgust, calmness vs excitement, calmness vs anger, fear vs anger) are classified by using Support Vector Machin...
Conference Paper
AMAÇ:Duyguların algılanması ve ifade edilmesi biçimlerini tanımlayan duygu düzenleme stratejilerini farklı sıklıklarda kullanan sağlıklı erişkinlerde, spontan beyin aktivitelerinin bilişsel yeteneklere bağıl olduğunu, hemisferler-arası EEG senkronizasyonu cinsinden sayısal indikatörlerle göstermek. YÖNTEM:Bilişsel yetenekleri arasında çok açık fark...
Conference Paper
Full-text available
AMAÇ: Duyguların algılanması ve ifade edilmesi biçimlerini tanımlayan duygu düzenleme stratejilerini farklı sıklıklarda kullanan sağlıklı erişkinlerde, spontan beyin aktivitelerinin bilişsel yeteneklere bağıl olduğunu, hemisferler-arası EEG senkronizasyonu cinsinden sayısal indikatörlerle göstermek. YÖNTEM: Bilişsel yetenekleri arasında çok açık...
Conference Paper
Bu çalışmanın amacı sağlıklı erişkinlerde bilişsel ve davranışsal duygu düzenleme yeteneklerinin, beynin spontan çalışma mekanizmasını ve nöral aktiviteleri etkilediğini sayısal olarak göstermektir. EEG tabanlı ve yönlendirilmemiş Çizge Kuramı modelleri ile derin öğrenme modelleri birleştirilmiştir. Birbirlerine göre zıt bilişsel yeteneklere sahip...
Poster
Full-text available
Bu çalışmada, hem fonksiyonel (Pearson Korelasyonu) hem efektif (Kısmi Yönlendirilmiş Koherens) yöntemler kullanılarak akustik seslerin uyandırdığı duygu durumlarıyla ilişkili olan çizgi kuramsal beyin bağlantısallık indisleri hesaplanmıştır ve bu yöntemlerin EEG kayıtlarından duygu tanıma başarıları ölçülmüştür. EEG kayıtları, katılımcıların 12 sn...
Poster
Full-text available
Bu çalışmada, dikkat eksikliği/hiper aktivite bozukluğu (DEHB) tanısı alan 18 pediatrik hastada, 1 ay süreyle özdeş talimatlarla aldıkları oral ilaç tedavisinin beyin fonksiyonları üzerindeki etkisi Çizge Kuramına dayalı EEG analizleri ile sayısal olarak araştırılmıştır. Nörofonksiyonel indikatörler olarak kabul edilen beyin ağı indisleri, tüm hast...
Article
Objective: Complexity analysis is a method employed to understand the activity of the brain. The effect of methylphenidate (MPH) treatment on neuro-cortical complexity changes is still unknown. This study aimed to reveal how MPH treatment affects the brain complexity of children with attention deficit hyperactivity disorder (ADHD) using entropy-bas...
Preprint
Full-text available
The study includes Graph Theoretic advanced EEG analysis in order to investigate the impact of pharmacological treatment with osmotic release oral system-methylphenidate for a month in 18 boys (aged between 7-12 years) with Attention-Deficit-Hyperactivity Disorder, combined type. In analysis, neurofunctional dependency levels across the cortex are...
Conference Paper
Full-text available
Introduction: Attention deficit hyperactivity (ADHD) disorder is a common childhood neurodevelopmental disorder, and methylphenidate (MPH) is a first-line therapeutic option for treating ADHD. However, how brain complexity and entropy changes with methylphenidate treatment the clinical implications of possible changes in entropy and the clinical im...
Article
Full-text available
Introduction Attention deficit hyperactivity (ADHD) disorder is a common childhood neurodevelopmental disorder, and Methylphenidate (MPH) is a first-line therapeutic option for treating ADHD.However, how brain complexity and entropy changes with methylphenidate treatment the clinical implications of possible changes in entropy and the clinical impl...
Conference Paper
The goal of this study is to test the hypothesis that the neuronal communication pathways, which enable neurocortical transmission, are mostly shaped by individual lifestyle as well as cognitive ability in managing positive/negative emotions. For this purpose, 64-channel spontaneous EEG data collected from participants, who frequently use some of t...
Conference Paper
The goal of this study is to test the hypothesis that the neuronal communication pathways, which enable neurocortical transmission, are mostly shaped by individual lifestyle as well as cognitive ability in managing positive/negative emotions. For this purpose, 64-channel spontaneous EEG data collected from participants, who frequently use some of t...
Poster
Full-text available
İnsanlarda duygusal değişimlerin, bireysel deneyimler, eğitim ve kültüre bağlı olarak değişkenlik gösterdiği tartışılmakta olsa da, nöro-fizyolojik değişimler sonucu hissettiğimiz duygusal durumlar sinir-bilim alanında evrensel tanımlanır. Bu nedenle, EEG sinyallerinden bir bireyin duygusal durumunun anlaşılması veya evrensel afektif uyarana vermes...
Conference Paper
Full-text available
Özet https://www.tfbd.org.tr/yuklemeler/45_fizyoloji_kongresi_ozet_kitabi.pdf Giriş ve Amaç: ‘Duygu düzenleme’ terimi, insanların günlük yaşamlarında duygularını yönetebilme kabiliyetlerini tanımlar. Bu terim, duygu-biliş etkileşimlerinin bir alt tipi olarak değerlendirilebileceği için, duygu düzenleme stratejileri ile sinir sistemi fonksiyonları...
Preprint
Full-text available
Resting-state brain networks represent the intrinsic state of the brain during the majority of cognitive and sensorimotor tasks. However, no study has yet presented concise predictors of task-induced vigilance variability from spectrospatial features of the pre-task, resting-state electroencephalograms (EEG). We asked ten healthy volunteers (6 fema...
Conference Paper
A real-time assessment of sustained attention requires a continuous performance measure ideally obtained objectively and without disrupting the ongoing behavioral patterns. In this work, we investigate whether the phasic functional connectivity patterns from short-and long-range attention networks can predict the tonic performance in a long Sustain...
Article
Full-text available
In the present study, the level of nonlinear inter-hemispheric synchronization has been estimated by using wavelet correlation (WC) method for detection of emotional dysfunctions. Due to non-stationary nature of EEG series in addition to the assumption that the high-frequency band is possibly associated with emotional activation, WC has been applie...
Article
Full-text available
Four asymmetry measurements (conventional coherence function (CCF), cross wavelet correlation (CWC), phase lag index (PLI), and mean phase coherence (MPC)) have been compared to each other for the first time in order to recognize emotional states (pleasant (P), neutral (N), unpleasant (UP)) from controls in EEG sub-bands (delta (0–4 Hz), theta (4–8...
Article
Full-text available
Obsesif Kompulsif Bozuklular (OKB) başka psikiyatrik belirtilerin de eşlik edebildiği nöropsikiyatrik bir hastalıktır. OKB için başlıca klinik değerlendirme kriteri, Yale-Brown Obsesyon Kompulsiyon Ölçeği (YBOKÖ) olsa da bunun yanı sıra, Hamilton Depresyon Değerlendirme Ölçeği (HDDÖ), Beck Anksiyete Ölçeği (BAÖ)de kullanılmaktadır. Bu çalışma da OK...
Article
Abstract Global field synchronization (GFS) quantifies the synchronization level of brain oscillations. The GFS method has been introduced to measure functional synchronization of EEG data in the frequency domain. GFS also detects phase interactions between EEG signals acquired from all of the electrodes. If a considerable amount of local brain neu...
Article
Global field synchronization (GFS) quantifies the synchronization level of brain oscillations. The GFS method has been introduced to measure functional synchronization of EEG data in the frequency domain. GFS also detects phase interactions between EEG signals acquired from all of the electrodes. If a considerable amount of local brain neurons hast...
Article
Full-text available
Objective: Studies investigating the complexity in electroencephalography (EEG) in various neuropsychiatric disorders have yielded abnormal results. However, few studies have examined EEG complexity in obsessive-compulsive disorder (OCD). Methods: An eyes-closed scalp EEG series of 3 minutes was recorded in drug-naive patients with OCD and in healt...
Chapter
In this study, different data mining techniques has been used for classification of healthy controls and patients diagnosed by First Episode Psychosis with respect to complexity of frequency band activities (Delta, Theta, Alpha, Beta, Gamma)in multi channel EEG measurements mediated by emotional, static and visual stimuli including affective pictur...
Conference Paper
In the present study, entropy values of EMG series, collected from arms and legs of healthy volunteers by using 8 recording channels in both normal and agressive actions, by using six different methods (Lempel-Ziv Entropy, Shannon Entropy (ShanEn), Logarithmic Energy Entropy, Approximate Entropy, Sample Entropy, Permutation Entropy (PermEn)) have b...
Conference Paper
Full-text available
Obsessive Compulsive Disorders causes disruptive effect on brain oscillations. One of this disruptive effects is loss of synchronization. Global Field Synchronization indice that is calculated by Global Field Synchronization Method can detect degree of synchronization of EEG. According to analysis results, significantly difference was found between...
Conference Paper
In the present study, linear, non-linear and statistical approaches so named Fourier Correlation, Wavelet Correlation (WC) and Pearson Correlation, respectively have been used to estimate cross-correlations between electrical muscle activities collected from two symmetric muscles and the these methods have been compared to each other with respect t...
Article
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 o...
Article
Full-text available
Objective: Some studies on schizophrenia showed an increased complexity in electroencephalography (EEG) whereas others detected a decreased complexity. Because this discrepancy might be due to the clinical features or complexity measures used, we employed two different complexity measures in a group of schizophrenics similar in illness duration (ch...
Conference Paper
This invited presentation, the principles of neuro-prosthetics have been briefly given by engineering point of view. And then, the applications have been reviewed with respect to important examples over the world.
Conference Paper
EEG analysis has been used in pathophysiological research of Obsessive Compulsive Disorder (OCD) that is one of the neuropsychiatric disease. EEG abnormalities was observed in brain cortex of patients with OCD. Fast Fourier Transform (FFT) Dipol Approximation Method (FFTDA), used for source localization and superior to conventional FFT method, has...
Conference Paper
Full-text available
zetçe Nöropsikiyatrik bir hastalık olan Obsesif Kompulsif Bozukluğun (OKB), patofizyolojik araştırmalarında EEG analizi kullanılmaktadır. Önceki yıllarda gerçekleştirilen EEG tabanlı OKB araştırmalarında beyin korteksinde anormal fonksiyonlar gözlenmiştir. Kaynak lokalizasyonu amacıyla kullanılan ve konvansiyonel Hızlı Fourier Dönüşümü (HFD) Yöntem...
Article
The primary goal of this study is to state the clear changes in functional brain connectivity during all night sleep in psycho-physiological insomnia (PPI). The secondary goal is to investigate the usefulness of Mutual Information (MI) analysis in estimating cortical sleep EEG arousals for detection of PPI. For these purposes, healthy controls and...
Article
In the present study, both single channel electroencephalography (EEG) complexity and two channel interhemispheric dependency measurements have newly been examined for classification of patients with obsessive–compulsive disorder (OCD) and controls by using support vector machine classifiers. Three embedding entropy measurements (approximate entrop...
Article
The primary goal of this study is to state the clear changes in functional brain connectivity during all night sleep in psycho-physiological insomnia (PPI). The secondary goal is to investigate the usefulness of Mutual Information (MI) analysis in estimating cortical sleep EEG arousals for detection of PPI. For these purposes, healthy controls and...
Article
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...
Conference Paper
zetçe Obsesif Kompulsif Bozukluk (OKB) hastalığı nöropsikiyatrik bir beyin hastalığıdır ve bu hastalığın teşhis, tedavi sürecinde EEG analizi kullanılmaktadır. Yapılan çalışmalar bu hastalığın beynin frontal lobunda bulunan işlev bozuklukları nedeniyle oluştuğunu göstermektedir. EEG senkronizasyonunda yeni bir ölçüt olarak geliştirilen Global Alan...
Conference Paper
In the present study, three well known embedding entropy approaches so called Approximate Entropy (ApEn), Sample Entropy (SamEn) and Permutation Entropy (PerEn) were applied to five experimental data sets consisting of both healthy surface Electo Encephalo Graphic (EEG) signals and epileptic intracortical measurements to obtain the EEG based charac...
Conference Paper
In the present study, multichannel EEG complexity has newly been examined for identification of obsessive-compulsive disorder (OCD). Since, EEG series is non stationary signal in nature, resting state eyes closed 19-channel EEG measurements of 3 min were segmented by using a specified window of 2 sec before applying the complexity and coherence met...
Article
In the present study, both linear and nonlinear EEG synchronization methods so called Coherence Function (CF) and Mutual Information (MI) are performed to obtain high quality signal features in discriminating the Central Sleep Apnea (CSA) and Obstructive Sleep Apnea (OSA) from controls. For this purpose, sleep EEG series recorded from patients and...
Article
Full-text available
Inter-hemispheric sleep EEG coherence is studied in 10 subjects with psycho physiological insomnia, in 10 with paradoxical insomnia, and in 10 matched controls through different states of the sleep/wakefulness cycle. Inter hemispheric EEG coherence between central electrode pairs are compared to each other within these groups. A linear measure call...
Article
In the present study, the Singular Spectrum Analysis (SSA) is applied to sleep EEG segments collected from healthy volunteers and patients diagnosed by either psycho physiological insomnia or paradoxical insomnia. Then, the resulting singular spectra computed for both C3 and C4 recordings are assigned as the features to the Artificial Neural Networ...
Article
In the present study, the Singular Spectrum Analysis (SSA) is applied to sleep EEG segments collected from healthy volunteers and patients diagnosed by either psycho physiological insomnia or paradoxical insomnia. Then, the resulting singular spectra computed for both C3 and C4 recordings are assigned as the features to the Artificial Neural Networ...
Conference Paper
In this study, to obtain high quality signal features in discriminating the Central Sleep Apnea (CSA) and Obstructive Sleep Apnea (OSA) from controls, both linear and nonlinear EEG synchronization methods so called Coherence Function (CF) and Mutual Information (MI) are performed. For this purpose, sleep EEG series data collected from patients and...
Article
In this study, to obtain high quality signal features in discriminating the Central Sleep Apnea (CSA) and Obstructive Sleep Apnea (OSA) from controls, both linear and nonlinear EEG synchronization methods so called Coherence Function (CF) and Mutual Information (MI) are performed. For this purpose, sleep EEG series data collected from patients and...
Article
In the present study, linear orthogonal projection algorithms (least square sense linear mapping (LSLM), minimum variance estimation (MVE), spectral domain estimation (SDC) and time domain constraint (TDC)) have been applied to reduce the background EEG noise on small number of trials elicited by auditory stimuli. These methods are compared to each...
Article
Full-text available
In the present study, a step-wise least square estimation algorithm (SLSA), implemented in a Matlab package called as ARfit, has been newly applied to clinical data for estimation of the accurate Auto-Regressive (AR) model orders of both normal and ictal EEG series where the power spectral density (PSD) estimations are provided by the Burg Method....
Article
Full-text available
In this study, normal EEG series recorded from healthy volunteers and epileptic EEG series recorded from patients within and without seizure are classified by using Multilayer Neural Network (MLNN) architectures with respect to several time domain entropy measures such as Shannon Entropy (ShanEn), Log Energy Entropy (LogEn), and Sample Entropy (Sam...
Article
Full-text available
In the present study, well known scale-space filtering (SSF) algorithm is used in combination with a linear mapping approach (LMA) to obtain clear auditory evoked potential (EP) waveform. The proposed combination involves two sequential steps: At first, the EEG noise level is reduced from -5 to 0 dB owing to the LMA based on the singular-value-deco...
Article
Full-text available
The present study compares two Auto-Regressive (AR) model based (Burg Method (BM) and Yule Walker Method) and two subspace based (Eigen Method and Multiple Signal Classification Method) power spectral density predictors in computing the Coherence Function (CF) to observe EEG synchronization between right and left hemispheres. For this purpose, two...
Article
Full-text available
In the present study, standard Tikhonov regularization (STR) Technique and the subspace regularization (SR) method have been applied to remove the additive EEG noise on average auditory-evoked potential (EP) signals. In methodological manner, the difference between these methods is the formation of regularization matrices which are used to solve th...
Article
Full-text available
In the present study, the performances of two well-known linear filtering techniques are compared for extraction of auditory Evoked Potential (EP) from a relatively small number of sweeps. Both experimental and simulated data are filtered by the two algorithms into two groups. Group A consists of Wiener filtering (WF) applications, where convention...
Conference Paper
In the present study, parametric methods of Burg and Music are performed to estimate power spectral densities of intracranial epileptic EEG records. The results show that the high order Burg method is more useful in detecting of ictal spikes within 0–5 Hz. Besides, low frequency components of epileptic EEG are observed via lower order Music method.
Conference Paper
In the present study, eyes open and eyes closed EEG records of healthy volunteersa and intracrinal EEG records of epilepsy patiants are analysed by the Burg Method. The results of power spectral densities shows that clinical long EEG data correspondes with high order autoregressive (AR) model. The higher frequency resolution is obtained as empirica...
Conference Paper
The current work address two types of Tikhonov regularization to extracta template evoked potential (EP) signal from a small number of noisy records. Under the same goal, the subspace regularization technique (SRT) was experienced in literature without comparison regarding as the standard form Tikhonov regularization technique (STRT). Both methods...
Conference Paper
Full-text available
The aim of this study is to assess the performance of additivity-based linear filtering techniques into two groups in extracting of auditory evoked potentials (EPs) from a relatively small number of sweeps. We named these groups as: Group A (the Wiener filtering (WF) and coherence weighted WF (CWWF) of orthogonal projections) and Group B (standard...
Conference Paper
Full-text available
The current study presents an automatic EEG noise filtration to reduce the background EEG noise from noisy brain evoked potentials. A small number of observations are projected onto the well-approximate signal subspace without any prior information. The stationarity of the evoked potential is not questioned in the proposed algorithm. Possible ampli...
Article
Full-text available
In estimating auditory Evoked Potentials (EPs) from ongoing EEG the number of sweeps should be reduced to decrease the experimental time and to increase the reliability of diagnosis. The ¯rst goal of this study is to demon- strate the use of basic estimation techniques in extracting auditory EPs (AEPs) from small number of sweeps relative to ensemb...

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Project (1)
Project
EEG processing and analysis tools are crucial to understand the mechanism of brain functions depending on neuro-physiological, cognitive and psychiatric factors. In the project, four groups of emotional states are modeled based on Graph Theory by means of hemispheric connectivity.