What is the point that is 20% anterior to Cz?

The point that is 20% anterior to Cz is indeed Fz. In the 10-20 system of electrode placement used in electroencephalography (EEG) and other applications, electrode positions are referenced to specific points on the skull. Cz represents the vertex of the head, and Fz is located in the frontal region directly in front of Cz.

When assessing the 10-20 system, it's important to know that the distances between electrodes are standardized. The notation of "20% anterior to Cz" indicates moving towards the frontal lobe from the central point (Cz), which directly leads to the placement of Fz. This positioning helps to better capture the activity from the frontal regions of the brain during monitoring.

Understanding the relative positions and the percentage calculations in the 10-20 system is crucial for accurate electrode placement in neurophysiological studies and intraoperative monitoring. Thus, the correct designation of Fz at 20% anterior to Cz aligns with these foundational principles.