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Methods for electroencephalogram records comparison
Mikešová, Tereza ; Ronzhina, Marina (referee) ; Janoušek, Oto (advisor)
This bachelor thesis starts with a theoretical section that explores the methods of electroencephalographic records analysis. The chosen methods are suitable for signal comparison. One of the methods, specifically STFT, is subsequently used in the practical segment. The aim of the practical section is to verify the ability of the proposed method to distinguish between the signals from two groups. For these purposes, rest and mental load records are used, the load being induced by counting mathematical examples. Of the examined power parameters, the differences in the ratio of beta and alfa band power and the relative power of alfa band showed the greatest statistical significance. The most appropriate setup of STFT seems to be with the shortest time window of 2 seconds.
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Assessment of Independent EEG Components Obtained by Different Methods for BCI Based on Motor Imagery
Húsek, Dušan ; Frolov, A. A. ; Kerechanin, J. V. ; Bobrov, P.D.
Eight methods of decomposition of a multichannel EEG signal are compared in terms of their ability to identify the most physiologically significant components. The criterion for the meaningfulness of a method is its ability to reduce mutual information between components; to create components that can be attributed to the activity of dipoles located in the cerebral cortex; find components that are provided by other methods and for this case; and at the same time, these components should most contribute to the accuracy of the BCI based on imaginary movement. Independent component analysis methods AMICA, RUNICA and FASTICA outperform others in the first three criteria and are second only to the Common Spatial Patterns method in the fourth criterion. The components created by all methods for 386 experimental sessions of 27 subjects were combined into more than 100 clusters containing more than 10 elements. Additionally, the components of the 12 largest clusters were analyzed. They have proven to be of great importance in controlling BCI, their origins can be modeled using dipoles in the brain, and they have been detected by several degradation methods. Five of the 12 selected components have been identified and described in our previous articles. Even if the physiological and functional origins of the rest of identified components’ are to be the subject of further research, we have shown that their physiological nature is at least highly probable.\n
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Methods for electroencephalogram records comparison
Mikešová, Tereza ; Ronzhina, Marina (referee) ; Janoušek, Oto (advisor)
This bachelor thesis starts with a theoretical section that explores the methods of electroencephalographic records analysis. The chosen methods are suitable for signal comparison. One of the methods, specifically STFT, is subsequently used in the practical segment. The aim of the practical section is to verify the ability of the proposed method to distinguish between the signals from two groups. For these purposes, rest and mental load records are used, the load being induced by counting mathematical examples. Of the examined power parameters, the differences in the ratio of beta and alfa band power and the relative power of alfa band showed the greatest statistical significance. The most appropriate setup of STFT seems to be with the shortest time window of 2 seconds.
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