In the 10-20 system, what percentage do the parasagittal planes Fp1 to O1 and Fp2 to O2 divide into?

In the 10-20 system, what percentage do the parasagittal planes Fp1 to O1 and Fp2 to O2 divide into?

• A. 10%
• B. 15%
• C. 20%
• D. 25%

Answer: (D)

In the 10-20 system of electrode placement, the electrodes placed in the parasagittal planes, which include Fp1 to O1 and Fp2 to O2, represent specific regions of the scalp. The 10-20 system is designed to provide a standardized way of positioning electrodes based on the size of the head, with measurements established in terms of percentages of the total head circumference. The segment from Fp1 to O1 represents a division of the scalp that is approximately 25% of the total distance from the frontal region to the occipital region on the left side of the head, as well as from Fp2 to O2 on the right side. This is because the entire longitudinal axis of the 10-20 system spans 100% from one side of the head to the other, and the divisions at Fp1 and O1, along with Fp2 and O2, encapsulate a quarter of that distance each. Thus, the correct identification of the percentage division for the parasagittal planes Fp1 to O1 and Fp2 to O2 is indeed 25%, making this a critical concept for understanding the layout of the electrode placements in the context of EEG studies

In the 10-20 system of electrode placement, the electrodes placed in the parasagittal planes, which include Fp1 to O1 and Fp2 to O2, represent specific regions of the scalp. The 10-20 system is designed to provide a standardized way of positioning electrodes based on the size of the head, with measurements established in terms of percentages of the total head circumference.

The segment from Fp1 to O1 represents a division of the scalp that is approximately 25% of the total distance from the frontal region to the occipital region on the left side of the head, as well as from Fp2 to O2 on the right side. This is because the entire longitudinal axis of the 10-20 system spans 100% from one side of the head to the other, and the divisions at Fp1 and O1, along with Fp2 and O2, encapsulate a quarter of that distance each.

Thus, the correct identification of the percentage division for the parasagittal planes Fp1 to O1 and Fp2 to O2 is indeed 25%, making this a critical concept for understanding the layout of the electrode placements in the context of EEG studies