Which EEG electrode is half the distance from F8 to Fz?

Which EEG electrode is half the distance from F8 to Fz?

• A. F4
• B. Fp2
• C. C4
• D. F6

Answer: (A)

In the 10-20 EEG system, electrode positions along the frontal row show the left-to-right progression: midline Fz, then moving laterally to the right gives F4, then F8. The halfway point between Fz and F8 sits at the electrode that lies between them, which is F4. So this position best represents the mid-point on that frontal line. Other options aren’t on that specific line between Fz and F8. An electrode like Fp2 lies too anterior toward the front of the head; C4 is more central-right and posterior to Fz; and F6 sits further lateral/adjacent but not at the midway point between Fz and F8.

In the 10-20 EEG system, electrode positions along the frontal row show the left-to-right progression: midline Fz, then moving laterally to the right gives F4, then F8. The halfway point between Fz and F8 sits at the electrode that lies between them, which is F4. So this position best represents the mid-point on that frontal line.

Other options aren’t on that specific line between Fz and F8. An electrode like Fp2 lies too anterior toward the front of the head; C4 is more central-right and posterior to Fz; and F6 sits further lateral/adjacent but not at the midway point between Fz and F8.