BrainWave Generator - Theory. The dominant frequency in the EEG pattern determines what shall be called the current state of the brain.
If the amplitude of the alpha range frequencies is highest, then the brain is said to be in the alpha stage. Note, that other frequencies still exist and it is impossible to give any "exact frequency your brain is operating on". However, later references to the brain states use the simplification of assuming that such a single frequency exists. When the brain's state is close to the applied stimulus, entrainment works more efficiently. RedASLA. Artesonoro.org.