Studies

As it is known Biofeedback (Bfb) is considered to be an important factor in attaining relaxation which is reflected in increasing of alpha waves on a background EEG. We found out that alpha-rhythm reactivity to light can characterize the condition of brain function. We determine the coefficient of alpha-rhythm reactivity showing the correlation between the alpha-index on the background EEG and alpha-index during eyes opened as:

As it was reflected by our latest research data (including those mentioned in the publications on our website in www. encephalography.com), this coefficient varies greatly in central nervous system disorders (epilepsy, CVA, syncope, neurotic disorders, space-occupying processes), and also depends on age. This coefficient also varies at different stages of a lesson. We examined ten healthy students age fourteen, at a chemistry lesson. At the beginning of the lesson, the coefficient reactivity was approaching three. After the lesson without bfb, it was equal to about two when bfb was used it was approaching three again. This fact testifies to the improvement of alpha-reactivity consequently to the reduction in tiredness under the influence of bfb. The study leads to the conclusion of the necessity of further research in this field and of the importance of active using biofeedback directly in learning process.

The aim of the present study was to compare EEG's in brain circulatory disturbances (cerebral-hemiospheric insult) and brain hemiospheric tumor to evaluate if they were certain specific features. The patients had similar clinical picture. We examined EEG in dynamic of twenty adults patients with vascular disease(they have been diagnosed at the neurology meeting), twenty patients with brain tumor of anterior region( diagnosis was proven in autopsy), and twenty healthy subjects. The patients were not given medications like benzodiazepenes. It has been noted: high voltage beta-rhytm sometimes looked like myogenic artifacts, was significantly better developed in group with vascular disease(80%). It was registered bylateraly in anterior leads and could be superposed on the delta-base. In patients with tumor they were 20% of such cases. The healthy subjects have not shown this waves. Teta-rhytm was developed better in vascular cases(60%), sometimes unremovable pulse and ECG artyfacts were registered. Delta waves were more marked and slower, notice in tumors in 80%. In dynamic they increased often, and in vascular cases they were mostly not changed or disapeered. To eye opening beta-activity remained, delta-activity was reduced in vascular cases.

The goal of these experiments is to examine changes of Human EEG after use of the cell phone. For this purpose, we decided to observe the changes of bioelectrical activity of brain in the background EEG without any influences and in the EEG record after cell phone radiation. Cell phone LG was used (Verizon wireless service). EEGs were performed on 6 practically healthy subjects at the age range from 55 years old. to 79 years old. old. (5 males and 1 female). Routine visual analysis of the background EEG revealed that the alpha-rhythm in all subjects was of low voltage, which confirmed previous studies about low amplitude in the third age group (R .Shmelkina, 1978) and we noticed also that bioelectrical activity reacted to eye opening after cell phone almost in the same way as before cell exposure. The EEG wave is usually described by its amplitude and percentage of time the waves are recorded. Alpha-index is defined as mean frequency of brain potential weighed over all bands of the EEG and can be calculated by percentage of time. (E .Niedermeyer, 1984 and others.) Alpha-power is the corresponding mean of alpha- amplitude Assuming that alpha-rhythm is an indicator of response to light stimuli and characterizes the functional state of the brain( R. Shmelkina 1976 and others) we decided to study the same parameters of alpha-rhythm as we did before. They are:1. the index-alpha-rhythm expressed in percentage of time.2. the average alpha-power obtained in the frequency machine analysis.

As slow waves were not visually sensitive to phone, the basic rhythm, alpha-rhythm, was under our attention. We made the study of main rhythm of EEG with the help of visual method and with the help of EEG machine frequency spectral analysis as well. The bioelectrical activity of brain was performed according to the regulations of ASET. The bioelectrical potentials were recorded from 4 brain areas: frontal, temporal, parietal and occipital lobes from both sides. The bipolar leads were used. Electrodes were attached by the International 10-20 system of electrode placement. Records were performed with the digital EEG machine "Nuritor". Portions of EEG in the background and after use of the cell phone were compared to each other. The automatic machine analysis showed that alpha-frequency didn't reveal much difference in the background EEG and after cell phone exposure and had a range from 9-10 Hz.

Results: The obtained data from the table and bar graphs showed that after the phone values of alpha-index, were reduced in 3 cases and in 3 cases, on the contrary, were increased.(50/50). So, we found that cell phone affects the EEG in 2 opposite directions. Regarding the obtained values of alpha-power parameter: in 2 subjects’ alpha-power was reduced under phone exposure, in 4 subjects the values of alpha-powers were increased. We suggest that influence of cell phone exposure may be considered as nonspecific influence and can be associated with the baseline functional condition of the central nervous system. More observations of the influence of cell phone radiation on EEG in the different physiological stages are required. It is necessary to find out the duration of phone effect if it exists, relationship to age, gender and environmental factors.