7/31/2019 10-20 System (EEG) - Wikipedia, The Free Encyclopedia

http://slidepdf.com/reader/full/10-20-system-eeg-wikipedia-the-free-encyclopedia 1/2

3/04/2012 10-20 sstem (EEG) - Wikipedia, the free encclopedia

1/2n.wikipedia.org/wiki/10-20_sstem_(EEG)

10-20 sstem (EEG)From Wikipedia, the free encyclopedia

The 10-20 sstem or International 10-20

sstem is an internationally recognized method to

describe and apply the location of scalpelectrodes in the context of an EEG test or 

experiment. This method was developed to ensure

standardized reproducibility so that a subject's

studies could be compared over time and subjects

could be compared to each other. This system is

 based on the relationship between the location of 

an electrode and the underlying area of cerebral

cortex. The "10" and "20" refer to the fact that theactual distances between adjacent electrodes are either 10% or 20% of the total

front-back or right-left distance of the skull.

Each site has a letter to identify the lobe and a number to identify the hemisphere

location. The letters F, T, C, P and O stand for frontal, temporal, central, parietal,

and occipital lobes, respectively. Note that there exists no central lobe, the "C" letter 

is only used for identification purposes only. A "z" (zero) refers to an electrode

 placed on the midline. Even numbers (2,4,6,8) refer to electrode positions on theright hemisphere, whereas odd numbers (1,3,5,7) refer to those on the left

hemisphere.

Two anatomical landmarks are used for the essential positioning of the EEG

electrodes: first, the nasion which is the point between the forehead and the nose;

second, the inion which is the lowest point of the skull from the back of the head and

is normally indicated by a prominent bump.

When recording a more detailed EEG with more electrodes, extra electrodes are

added utilizing the spaces in-between the existing 10-20 system. This new electrode-

naming-system is more complicated giving rise to the Modified Combinatorial

omenclature (MCN). This MCN system uses 1, 3, 5, 7, 9 for the left hemisphere

which represents 10%, 20%, 30%, 40%, 50% of the inion-to-nasion distance

respectively. The introduction of extra letters allows the naming of extra electrode

sites. Note that these new letters do not necessarily refer to an area on the underlying

cerebral cortex.

References

7/31/2019 10-20 System (EEG) - Wikipedia, The Free Encyclopedia

http://slidepdf.com/reader/full/10-20-system-eeg-wikipedia-the-free-encyclopedia 2/2

3/04/2012 10-20 sstem (EEG) - Wikipedia, the free encclopedia

2/2n.wikipedia.org/wiki/10-20_sstem_(EEG)

Ernst Niedermeyer, Fernando Lopes da Silva, Electroencephalography: Basic

Principles, Clinical Applications, and Related Fields - Page 140

(http://books.google.com/books?id=Ci6aVlN_NR4C&pg=PA140&dq=10-

20+system) , Lippincott Williams & Wilkins, 2004 ISBN 0-7817-5126-8,

9780781751261.

Eternal links

SVG drawing of the 10-20 system

(http://www.mariusthart.net/downloads/eeg_electrodes_10-20.svg) (PDF

(http://www.mariusthart.net/downloads/eeg_electrodes_10-20.pdf) )

10-20 System, numbering seen as a subset of the 10% division

(http://www.bem.fi/book/13/13.htm#03)

Retrieved from "http://en.wikipedia.org/w/index.php?title=10-

20_system_(EEG)&oldid=469405768"

Categories: Electroencephalography Electrophysiology Neurophysiology

This page was last modified on 3 January 2012 at 22:22.

Text is available under the Creative Commons Attribution-ShareAlike

License; additional terms may apply. See Terms of use for details.

Wikipedia is a registered trademark of the Wikimedia Foundation, Inc., anon-profit organization.