Measured activity between two electrode pairs is referred to as?

• A. Unipolar
• B. Tripolar
• C. Multipolar
• D. Bipolar

Answer: (D)

Bipolar recording uses the differential voltage between two closely spaced electrodes. By measuring the difference between these two contacts, the setup emphasizes local activity at the electrode sites while canceling much of the common noise and far-field signals that both electrodes pick up. This makes the signal more spatially specific than a unipolar recording, which compares one electrode to a distant reference and tends to include more global activity. Tripolar and multipolar configurations involve more electrodes to further suppress far-field noise or to map activity over a region, but the essential idea here—measuring between two electrodes as a differential pair—defines a bipolar recording.