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ERP correlates of valence in affective priming
MEŠKANOVÁ, Michaela
The bachelor thesis, ERP (event-related potentials) correlates of the valence in affective priming, deals with the affective priming from the point of view of the event related potentials processing by electroencephalography, when it is used experimental presentations with different valence and arousal levels. The aim of this thesis is the approaching of the auditory priming effect on the visual processing impulse. This bachelor thesis is divided into theoretical and practical part, where the theoretical part deals with the general principles of the affective priming, emotions and electroencephalography method, including ERP component. The empirical part deals with the experiment, whose aim was description of the auditory priming effect on the affective processing target by the ERP components. Twenty six respondents took part in the experiment. They saw a presentation made in OpenSesame programme in the total length of sixty minutes. The neural data were scanned from the head scalp by the device Biosemi ActiveTwo with 64 electrodes. In the final processing there were 19 measured samples. After the final processing, I analysed 8 graphs displaying ERP curved lines of the relevant electrodes both the high-arousal and low-arousal processing target level. In the comparison with the studies not including affective auditory priming, all given hypothesis were approved. The final discussion summarizes all possible restrictions that could influence acceptance of the alternative hypothesis.
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EEG ERP inhibitory response of selective attention in bilingual subjects
JANOUŠKOVÁ, Nikola
This bachelor thesis continues in research of bilingual subjects and investigates differences in cognitive functions (especially selective attention). It compares speed and accuracy of bilingual and monolingual responses on verbal stimuli (font detection) during which are observed subjects affected by tone with acoustic pressure of 76 dB. In theoretical part of the thesis I elaborated information about language and speech in general, language development, bilingualism, electroencephalography and of course about speech in neuropsychology. In empirical part there is described research methodology, elaboration and analysis of data, which was gained during the experiment. It?s assumed that bilingual subjects should have different values of event-related potentials, especially in linguistic part of the brain and according to behavioral data should show their cognitive advantage in less error rate. Two types of data were obtained from the experiment ? behavioral and EEG records. Behavioral data were processed in Excel and EEG records in the MATLAB programming environment. The results confirmed intergroup differences in ERP components, but these results were inconsistent within behavioral data, which can be attributed primarily to sample size.
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Vietnamese-Czech bilingual adolescents on EEG - bilingual effect on cognitive advantage
ŠIMKOVÁ, Kateřina Marie
A recently progressive topic of psychology are aspects of humans psyché. It is raised in the most complicated matter human could ever explore. In the brain. This bachelor thesis briefly concludes cerebral mechanisms of neuroplasticity and its influence on humans life. Concretely the theoretical part is specialized on a cognitive advantage of bilingualism. The mentioned advantage was studied in empirical part by electroencephalographic measurement in Vietnamese-Czech bilinguals during letter detection task. We expected bilinguals to outperform control group of monolinguals in behavioral part. Due to a different neural organization within linguistic plasticity, we also expected different amplitudes in event-related potentials in the bilingual group in linguistic areas of the brain. Results confirm mentioned neural differences, although behavioral advantage hypothesis is falsified.
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The influence of the nucleus accumbens on perception of facial expressions
VALUCHOVÁ, Kateřina
The bachelor thesis deals with the research of the stimulation of nucleus accumbens with laughter and the influence of this stimulation on the perception of facial expressions. The theoretical part is focused on an anatomical and functional description of nucleus accumbens and related researches. The information on laughter, facial expressions as well as electroencephalography (EEG) and event related potentials (ERP) are processed in the theoretical part. The empirical part introduces a research methodology that aims to determine the influence of laughter and associated nucleus accumbens stimulation on the perception and evaluation of neutral and positive facial expressions (obtained from the KDEF database). The experiment was attended by 16 subjects. The funny videos were showed to the subjects and each of them had the task to evaluate the presented facial expression. Neural data were obtained using an electroencephalogram and processed through the Matlab program, specifically in its EEGlab toolbox. Behavioral data were processed in the Statistica program and a paired T-test was used for statistical analysis. The final analysis of neural and behavioral data included 15 subjects. The resulting analysis showed that despite the stimulation with a humorous stimulus there was a different treatment and evaluation of neutral and positive facial expressions at both neural and behavioral level, which was in contradiction with the established hypotheses. The results did not show that the humorous stimulus used to stimulate nucleus accumbens had a statistically significant effect on the evaluation of facial expressions.
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Neural correlates of emotional facial expressions perception
SLABÝ, Lukáš
This thesis deals with differences of perception of facial emotional expressions at the neural level. The theoretical part contains information about emotions, their basic theories and six basic emotional expressions. Furthermore, the theoretical part clarifies electroencephalography - the method of recording electrical activity of the brain and event-related potentials (ERP). The practical part is focused on the experiment, whose aim is to describe the differences in the event-realted potentials of perception of facial emotional expressions and neutral expression, to compare the event-related potentials of perception of positive and negative emotions and to compare event-related potentials of two databases of facial emotional expressions (WSEFEP, KDEF) which were used in this experiment. 13 subject participes in this experiment. The subjects were exposed to visual stimuli (facial emotional expressions) and the EEG signal were simultaneously recorded. This signal was further filtered and analyzed in Matlab and its EEGlab toolbox. A paired T-test and ANOVA were used for statistical data processing. Four hypotheses for this research were formed. The first hypothesis, which contended that the perception of facial emotional expressions would differ among each other in event-related potentials, was accepted. The second hypothesis, which claimed that there are differences in the event-related potentials of facial emotional expressions and neutral expressions, could not be accepted for lack of evidence. The third hypothesis, which asserted that there are differences in the event-related potentials of perception of positive and negative facial emotional expressions, was accepted. The fourth hypothesis, which asserted that there is a difference in the event-related potentials between the perception of facial emotional expressions from the WSEFEP database and the KDEF database, was accepted for sufficient evidence.
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