In modern EEG systems, where do the ground or common electrodes connect with respect to the electrical outlet?

In modern EEG systems, the ground or common electrodes are connected in a specific manner to ensure safety and reduce electrical interference. When the ground or common electrode is described as "common with" the electrical outlet, it means that the grounding system of the EEG equipment is tied to the earth ground of the electrical outlet. This connection helps to prevent electrical noise from affecting the EEG readings by establishing a reference point that is also used by other electrical equipment.

A shared ground with the outlet is significant because it helps maintain a stable baseline for the electrical signals being measured, thereby improving the clarity and accuracy of the EEG data. This setup also plays a crucial role in patient safety, as it minimizes the risk of electrical shock and ensures that any stray voltages are safely channeled away.

In contrast, if the ground or common electrodes were to connect separately, it could lead to differences in electrical potential that might distort the readings, introduce noise, or even compromise patient safety.