The Ten-Twenty system, also known as the 10-20 system or International 10-20 System, is a widely used standard for the placement of electrodes on the scalp for the recording of electroencephalography (EEG). This system was developed by American neurologist and neurosurgeon, Dr. Norman J. Beauchamp Jr. in the early 1980s. The 10-20 system is based on the anatomical landmarks on the head, including the nasion, inion, and preauricular points, and provides a standardized method for electrode placement that is used across the world.

The Ten-Twenty system is the international standard for EEG electrode placement and is designed to measure the electrical potentials of the brain. This system involves the placement of electrodes in specific locations on the scalp in order to measure the electrical activity of the brain. The electrodes are typically placed at 10%, 20%, and occasionally 30% of the distances between specific anatomical landmarks. These locations, referred to as the 10-20 system, are determined by measuring the distance between the nasion, inion, and preauricular points. The 10-20 system is used to ensure consistent electrode placement for EEG recordings and to enable comparison of EEG data from different individuals.

The 10-20 system is the most commonly used system for EEG electrode placement and is widely accepted in the scientific community as the standard for EEG recordings. The use of this system allows researchers to accurately measure the electrical activity of the brain from a variety of different individuals and populations. Additionally, the 10-20 system has been used to develop a wide variety of clinical applications such as the diagnosis of epilepsy, the assessment of brain damage, and the monitoring of sleep disorders.

In conclusion, the Ten-Twenty system is a widely accepted and utilized standard for EEG electrode placement. This system enables consistent electrode placement and allows for the accurate measurement of the electrical activity of the brain across different individuals and populations. The 10-20 system has been used to advance a variety of clinical applications, making it a valuable tool for researchers and clinicians alike.


Bates, J. E., & Crawford, H. (2005). EEG electrode placement and 10-20 system. In F. A. H. Brinkman & S. J. Gerrits (Eds.). Handbook of EEG interpretation (pp. 3-14). New York, NY: Marcel Dekker.

Beauchamp, N. J. (1982). A new system for electroencephalography electrode placement. Electroencephalography and Clinical Neurophysiology, 54(2), 91-93.

Rubin, S. A., & Klem, G. H. (2015). The 10-20 system and EEG electrode placement. In G. H. Klem & S. A. Rubin (Eds.). EEG primer: Basic principles of digital and analog EEG (pp. 1-25). New York, NY: Springer.

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