What type of montage uses source reference derivation?

The correct answer is the Laplacian montage. This type of montage is characterized by its use of source reference derivation, which involves calculating the potential at a given electrode in relation to the average potential of surrounding electrodes. The Laplacian method emphasizes local activity by reducing the influence of distant sources. This technique is particularly effective for enhancing the spatial resolution of the EEG signal, making it easier to identify specific cortical activities.

In contrast, other montages like bipolar and referential utilize different approaches to electrode pairing and referencing. The bipolar montage records the difference in electrical potential between two adjacent electrodes, while the referential montage typically measures the potential of each electrode against a common reference point, such as the average of all electrodes. The common montage, similar to referential, focuses on a shared reference but does not employ the localized differentiation that Laplacian does. Each of these methods captures different aspects of brain activity, but none utilize the source reference derivation characteristic of the Laplacian montage.