ALPHA RHYTHM AND CEREBRAL SYNCHRONIZATION

The Alpha EEG rhythm, characterized by a frequency between approximately 8 and 12Hz, is an important brain rhythm associated with calmness, relaxation, and creativity. Furthermore, numerous websites associate it with the concept of brain synchronization,meaning that an increase in the Alpha rhythm would imply an increase in synchronization between different areas of the brain. This effect is considered very positive for people's mental and physical well-being. In this study, two groups of subjects were selected, the first High-Alpha, the second Low-Alpha, characterized respectively by a naturally high and low Alpha rhythm. The average degree of brain synchronization in the two groups was then calculated using analyses based on Fourier Transformation, Pearsons Correlation, and EEG Coherence. The results show that Low-Alpha subjects have a higher average EEG synchronization value, with the sole exception of synchronization in the frontal and occipital lobes, which is higher in High-Alpha subjects. Brain synchronization is therefore not directly related with high Alpha rhythm, as homogeneous phenomenon across the entire cerebral cortex, but depends greatly on the phase relationships between brain waves in different locations on the scalp. A method for calculating coherence is also described, which allows for better highlighting of the phase relationships between two electrodes as a function of EEG frequency. Keywords: Alpha rhythm, eeg synchronization, coherence, Pearson correlation.