If the distance from T6 to Pz is stated as 8 cm, how far is it from C3 to Pz?

The correct answer is that the distance from C3 to Pz varies depending on head size. In electroencephalography (EEG) and sleep studies, the placement of electrodes is often determined using the 10-20 system, which relies on the dimensions of the head to ensure consistent and reliable electrode placement across different individuals.

The specific distances may not be the same for everyone due to variations in head circumference. While there are standard measurements for electrode placement, individual anatomical differences can lead to variations in those distances. Therefore, while the distance from T6 to Pz may be a fixed measurement (8 cm in this case), the distance from C3 to Pz is not universally defined and will indeed vary based on the individual’s head size. This understanding is crucial for accurate electrode placement to ensure consistent data collection in sleep studies and other neurological examinations.