| Abstrakt: |
The study provides the data related to synchronization/desynchronization when performing verbal creative (to create the endings of proverbs) and noncreative (to find a synonym for the ending of the known proverb; to remember the known ending of the proverb) tasks, as well as the data on classification of EEG patterns during these tasks. Twenty-four volunteers (18–22 y.o., 20 women, 4 men) participated in the study. Creation of original endings vs. memory task was accompanied by the higher values of EEG power in the frontal region of the right hemisphere in the frequency range 8–9 Hz for the time interval of 400–730 ms. In the parietal region of the left hemisphere in the same frequency range, the higher EEG spectral power EEG values were obtained while creating both original and synonymous endings compared to the "recall/memory" control task. When creating original and synonymous endings, the power of EEG was higher in the central frontal regions for the 14–15 Hz frequency band, as well as in the right hemisphere F4 and P4 used for the tasks with synonyms compared to the memory task (850–950 ms). For the frequencies of 17–21 Hz, there were no differences between the creative and synonymous tasks; at the same time, the creative task as compared to the task for memory was characterized by differences in the parietal sites bilaterally and in the central frontal region only for the frequencies of 17–18 Hz, while the synonyms task as compared to the memory one differed in the specified regions for the frequency range of 17–21 Hz. The EEG signal classification was carried out using the classifier learning software package in the matlab environment. The results of classification were considered on the basis of linear discriminant analysis, the support vector machine, and the method that gave the best classification result. An EEG signal converted to current source density (CSD) from frontal (F3, Fz, F4) and parietal regions (P3, Pz, P4) located on the surface of the skull according to the 10–20 System was used for classification. The average accuracy of single trial classification for three types of tasks in all subjects was 48.7 ± 5% [SD] for the best classifier; the best result of the individual subject (58.5%) was achieved using linear discriminant analysis at the theoretical threshold of random classification of 33%. [ABSTRACT FROM AUTHOR] |
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