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Spectral analysis of the EEG signal
Blatný, Michal ; Kozumplík, Jiří (referee) ; Hrozek, Jan (advisor)
Master’s thesis deal about electroencefalography, measurement EEG signals and analysis measuermed signals. Project contains two basis practical parts. Firts part contain two PC’s programs that’s are used to fundamental analysis to frequence-domain and visual display of brain mapping created with Matlab. Second chapter of practical parts includes two PC’s programs created with LabView. First of them is the EEG biofeedback making use for advanced analyses and second program is used to detection segment of stacionarity.
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EEG Signal Analysis during the Stroop Test
Tolaszová, Eva ; Roman,, Robert (referee) ; Sekora, Jiří (advisor)
Master’s thesis deals with the measurement of biological signals for the effect of psychological burden. To monitor this effect was elected Stroop test, which is in the psychology used to detect disorders of attention and concentration. EEG and ECG signals during Stroop test were obtained using the EEG recording systém, in the context of research evoked potentials. As a part of the work it has been designed custom application for analyzing and interpreting data and statistical analysis by t-test.
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Analysis of sleep EEG signal
Ježek, Martin ; Kozumplík, Jiří (referee) ; Rozman, Jiří (advisor)
Cílem této práce byl vývoj programu pro automatickou detekci arousalu v signálu spánkového EEG s použitím metod časově-frekvenční analýzy. Předmětem studie bylo 13 celonočních polysomnografických nahrávek (čtyři svody EEG, EMG, EKG a EOG), tj. celkově více než 100 hodin záznamu. Jednalo se o část dat z dřívějších výzkumných prací expertní lékařky v problematice spánku Dr. Emilie Sforzy, Ženeva, Švýcarsko, která rovněž poskytla základní hodnocení těchto dat. V záznamech bylo celkem označeno 1551 arousal událostí. Pro usnadnění výběru konkrétní metody časově-frekvenční analýzy byla následně vytvořena sada nástrojů pro vizualizaci jednotlivých signálů a jejich různých časově-frekvenčních vyjádření. S ohledem na závěry vizuální analýzy, charakter signálu EEG a efektivitu výpočetních metod byla pro analýzu vybrána waveletová transformace s mateřskou vlnkou Daubechies řádu 6. Jednotlivé svody EEG byly dekomponovány do šesti frekvenčních pásem. Z takto odvozených signálů a signálu EMG byly následně stanoveny ukazatele možné přítomnosti události arousalu. Tyto ukazatele byly dále váhovány lineárním klasifikátorem, jehož hodnoty vah byly optimalizovány pomocí genetického algoritmu. Na základě hodnoty lineárního klasifikátoru bylo rozhodnuto o přítomnosti události arousalu v daném svodě EEG – arousal byl detekován, jestliže hodnota klasifikátoru překročila danou mez na dobu více než 3 a méně než 30 vteřin. V celém záznamu pak byl arousal označen, byl-li detekován alespoň v jednom ze svodů EEG. Následně byly odvozeny míry senzitivity a selektivity detekce, jež byly rovněž základem pro stanovení fitness funkce genetického algoritmu. Pro učení genetického algoritmu byly vybrány první čtyři záznamy. Na základě takto optimalizovaných vah vznikl program pro automatickou detekci, který na celém souboru 13 záznamů dosáhl ve srovnání s expertním hodnocením míry senzitivity 76,09%, selektivity 53,26% a specificity 97,66%.
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Control of the electric wheelchair using EEG classification
Malý, L.
Electric wheelchairs are some of the most important devices to assist physically handicapped persons. This paper presents the concept of brain controlled electric wheelchair designed for people who are not able to use other interfaces such as a hand joystick, and in particular for patients suffering from amyotrophic lateral sclerosis (ALS). The objective is to control the direction of an electric wheelchair using noninvasive scalp electroencephalogram (EEG).
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The influence of computer games on aggressiveness
STANĚK, Jakub
This Bachelor Thesis deals with study of influence of computer games on aggression. The aim of this thesis is to find out whether computer games cause inclination to aggressive behaviour. The theoretical part is focused on scanning electrical brain activity. It contains description of electroencephalography, evoked potentials and brain waves. It also elaborates various psychological theories of aggression and connects them to relation with physiologist creation of aggressive behaviour. The empirical part is focused on a research project. It describes an experiment which examines reactions to positive, neutral and negative visual stimuli before and after playing computer games by spectral analysis. 42 people, chosen by quota selection, participated in the research. 29 probands got into the final analysis and outcomes. The data were processed by Matlab program and its toolbox EEGlab. The outcomes of spectral analysis and comparison of individual research groups show that violent computer games influence aggression.
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The effect of relaxation on affective stimuli processing
KOZOVÁ, Michaela
The main issue of this thesis is to analyze the effect of relaxation on visual affective stimuli. Relaxation influences emotional processing and related EEG response of the individual person. The thesis is divided into two thematic parts: the first on eis theoretical part and the second on eis empirical part. The first part deals with emotions as complex phenomenona. It describes topics as Affective events and Physiology and Regulation of emotions. Important chapter is devoted to the description of Relaxation techniques with focus on Imagination which is used in the experimental part of the thesis. The first empirical part of the thesis deals with experimental verification of the possibility to use relaxation in the unusual settings of a cognitive laboratory. The subsequent part describes EEG measure of brain activity related to processing of visual affective stimuli before and after relaxation. The data were statistically analysed using T-test with multiple FDR comparison. The data were suitable for ERPs - event related potencial analysis. The results of the study were compared with current neuropsychology knowledge.
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Development of .NET application for EEG neuroheadset
Sedlák, Vojtěch ; Brixí, Radim (advisor) ; Kalina, Jaroslav (referee)
This thesis analyzes Emotiv neuroheadset and included software. Its main goal is development of application, that displays, records and replay data from this device. Application is written in C# language on framework .NET. Paperwork is divided into five parts. The first part -- introduction focuses on problematics of research, and provide the aims and contributions. The work is further classified into theoretical, analytical and implementation part. In theoretical part author introduces biological background which is important for the base of research. In the following analytical part, the author perform the analysis of the device Emotiv and its software. From this knowledges come out the suggestion of his own proposals for aplication, which is situated in the implemented part. In the last part of the thesis the autor summarize the whole research and conclusiones which are the results of this thesis.
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EEG activity during emotional stimulation
HOROVÁ, Jana
The presented thesis deals with study of emotion and impact of emotional stimulation on Electroencephaography (EEG) signal. The aim of this statement is to determine if it is possible to detect different classes of emotionally charged words and to verify hypothesis, that there is a significant difference in event-related potential of emotional word to emotional content. The theoretical part is focused on the electrical activity of the brain over a period of time, the method of electroencephalography, event-related potentials (ERP), fundamental study of emotions, including stimulus material in regarding to examining of emotions and ERP of emotional response. There are also mapped factors correlating with the investigation of emotions. The practical part deals with the implementation of a the project examined using Experimental method where investigated ERP response to variously emotionally tinged and neutral words is. Research was attended by eleven undergraduate students, as the sampling method was used the method of snowballs. Data were processed and analyzed in EEGlab and then using of statistical analysis of variance method (ANOVA) and paired T-test evaluated.
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The neuropsychological correlates of emotions
TESAŘ, Michael
The presented thesis deals with localization of emotions and its processing according to visual emotional stimuli from IAPS. It uses EEG analysis and non-parametric statistics Kruskal-Wallis ANOVA, Wilcoxon's t-test. Results confirm hemispherical asymmetry theories and it was found a new localization of the neutral emotion in the left frontal alpha EEG asymmetry, which is not clearly described by other authors. Processing of emotions shows that complex affective reaction of positive and negative emotions is not significantly resolved; reversely the biggest resolving is the first processing time exposition automatic affective reaction. Acquisitions of the thesis are providing crucial theoretical knowledge for further EEG and emotion research, describing localization of the neutral emotions in the frontal cortex and processing of emotions in affective reaction to visual stimulation.
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