What is the percentage distance of Fp1 and Fp2 from Fpz?

To determine the percentage distance of Fp1 and Fp2 from Fpz, it is important to understand the positioning of these electrodes on the International 10-20 system used in EEG and other neurophysiological monitoring. Fpz is positioned at the front of the head, while Fp1 and Fp2 are slightly lateral to Fpz.

In the context of the 10-20 system, the distance from Fpz to Fp1 or Fp2 can be analyzed in relation to the total distance between the nasion and inion, which is the standard reference length used for these measurements. Fp1 and Fp2 are typically spaced about 10% of the total head measurement to the left and right of Fpz respectively.

Since the question asks for the distance from Fpz specifically, and given the overall distances involved in electrode placements, the positioning correlates to 5% of the distance for each electrode, leading to an understanding that the distance from Fpz to either Fp1 or Fp2 is indeed approximately 5%. Thus, the correct percentage distance is established as consistent with the conventions of the electrode placement system.