[Eeglablist] Average reference issue (channels become flat)

[Ramtin Mehraram (Student)]

Good evening,
I am finding an issue cleaning some resting state data acquired with a 128 channels ANT cap. The signals are initially referenced to Fz, that is actually flat. When I try to average re-reference, there is always one or two channels that become flat (usually external channels, but it happens also with more central ones), even if they look fine before the re-referencing. Is it unlikely that the activity of these channels corresponds exactly to the average activity of the entire scalp. What do you think is actually happening here?

Thank you in advance for your help

Ramtin Mehraram