Spectral analysis of EEG signals among people with different levels of personal anxiety

Introduction: The study of electrical activity peculiarities in the cerebral cortex among people with different levels of anxiety and the dependence of EEG rhythms from the level of personal anxiety (PA) is relevant and needs to be studied. As a result of our research, we have found that during the baseline EEG among people with a moderate level of personal anxiety, the intensity of alpha rhythm predominates in the posterior areas of the cerebral cortex. People with a high level of PA had the highest rates of beta rhythm intensity. An inverse relationship between EEG main rhythms and the level of anxiety is noted. Thus, people, who were involved in our study, with the moderate level of PA had the following results: the steadier the PA, the less the intensity of the PA level. People with a high level of PA had positive connections between the alpha and beta rhythms and level of anxiety, as well as a higher activity in the right-hemisphere of the cortex, which indicates the contribution of this hemisphere in the high level PA in studies. Material and methods: The power of EEG rhythms among people (aged 18–22) with different levels of anxiety was studied. Registration of the cerebral cortex electrical activity was carried out using the «Neurocom».device. During the electroencephalogram recording, electrodes were placed on the international system 10/20. The spectral power values were analyzed in the standard physiological frequency bands: delta (1–4 Hz), theta (4–8 Hz), alpha (8–14 Hz), beta (14–35 Hz). For the spectral EEG characteristics, an absolute (ACP, μV) and relative spectral power (RSP, %) were used. The analysis of power indices was carried out in a state of rest with closed eyes (baseline),and a state of rest with open eyes during task solving as an emotional load. Results: We have found that during the EEG baseline people with the moderate level of PA had high indexes of alpha rhythm in the posterior areas of the cerebral cortex. Eyes’ opening caused an increase of the intensity of theta rhythm in the frontal area of the cerebral cortex. During the intellectual task conducting, we noticed that the increase of intensity of beta rhythm in the frontal, temporal and end-lobe parts, whereas in the central and vertex parts of the cortex the intensity of theta rhythm predominated. Among people with a high level of PA during the baseline probe, the highest rates of beta rhythm intensity in the posterior areas of the cerebral cortex were fixed. In the stat