[Eeglablist] Baseline removal in dead channels

[Gorka Fraga Gonzalez]

Dear EEGlab experts,



I am analyzing data collected with a Biosemi 64 channels system.  After a
large sample tested one electrode did not get any signal in the last
subjects so it  was manually checked and apparently is dead.


However after preprocessing  data without excluding this channel I found a
normal ERP average. The data was analysed in EEglab as it follows:



  Import ref average of mastoids//  bandpass filter (1-70)// downsample to
256hz// Epoched// Remove baseline (…)



I found that it was only after the “remove baseline “step that I could see
signal in that channel when manually scrolling the data.



It would be great if any of you could give me an explanation on this, since
 after reading about what the “baseline removal” procedure does it is still
not clear to me why this could happen



Many thanks in advance

Gorka
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