In EEG, each electrode records a biopotential which must be compared to a reference biopotential in order to obtain a channel of measurement. Two types of channels are the so-called bipolar channels and monopolar channels. In the case of bipolar channels, each working electrode uses a different reference electrode, whereas in the case of monopolar channels, each working electrode uses the same electrode as reference.
From an amplifier-technical point of view, reusing a signal can degrade it a bit, so that is indeed bad for the monopolar channels. However, is there any fundamental difference between monopolar and bipolar channels? What if every two channels have a common reference electrode?
At this point I feel the need to mention there is another question mentioning the difference between the two, but it doesn't ask whether there is a conceptual difference between the two, nor does it compare their advantages and disadvantages (in addition to the one accepted answer being rather short in my opinion).
Additionally, this paper mentions that bipolar recordings are generally known to be more robust to noise than monopolar recordings: why would that be the case?