A Review of Eeg Recording Techniques

EEG is a collaborative tool to diagnosis brain function and disease. Modern interpretation of EEG origin rest with knowledge of basic neuronal electrochemical process. The EEG is composed of electrical rhythms and transient discharges which are distinguished by location, frequency, amplitude, form, periodicity and functional properties. The low-level EEG Signal from the brain as recorded is amplified and converted to a digital signal for further processing. EEG machines have a notch filter sharply tuned at 50Hz so as to eliminate main frequency interference. Reading has been taken in international 10-20 Electrode system for a normal person. EEG signal voltage amplitudes ranges 1 to 100 μv peak to peak at low frequencies(1 to 50 Hz) at the surface of scalp. In biofeedback training the ratio of amplitude of alpha to theta waves need to be increased. Keyword: Electroencephalogram(EEG), biofeedback, notch filter.