Which electrode site is found halfway between the inion and nasion?

Which electrode site is found halfway between the inion and nasion?

• A. Pz
• B. Fz
• C. Cz
• D. P4

Answer: (C)

In EEG setups, the nasion at the front of the skull and the inion at the back define the front–back axis along the midline. The site exactly halfway between these two landmarks on that midline sits at the top of the head—the vertex—and is labeled Cz. That central, midline position is why Cz is the correct answer: it’s the exact midpoint between front and back on the scalp. The frontal midline position would be farther toward the forehead, not at the midpoint. The parietal midline position sits farther back from Cz along the same line, not at halfway. A lateral parietal site is off the midline entirely, so it wouldn’t be halfway between nasion and inion.

In EEG setups, the nasion at the front of the skull and the inion at the back define the front–back axis along the midline. The site exactly halfway between these two landmarks on that midline sits at the top of the head—the vertex—and is labeled Cz. That central, midline position is why Cz is the correct answer: it’s the exact midpoint between front and back on the scalp.

The frontal midline position would be farther toward the forehead, not at the midpoint. The parietal midline position sits farther back from Cz along the same line, not at halfway. A lateral parietal site is off the midline entirely, so it wouldn’t be halfway between nasion and inion.