A really big doubt about ERP Baseline correction

Discussions
1

Good afternoon!
I would like to ask about baseline correction:

I calculated the p100 potential of a subject, and when importing it into the database, I selected the option to remove the baseline DC from -100 to 0. However, after averaging, I see that the signal before the start of the stimulus is not centered at 0.

A professor told me that the signal should be above 0 if I have already applied the baseline correction, but I have seen several articles where the pre-stimulus ERP signal is not centered at 0.

I am confused. Is the ERP I calculated correct, or is there a correction I need to apply?

Should the pre-stimulus ERP signal always touch zero?

Thanks in advance!

P100OMAR
P100OMAR608×598 63.5 KB

2

Hello – baseline correction over -100 to 0 ms removes the average of each time series across this time segment. The signal can therefore fluctuate around 0 over that time period, which seems to be the case in your figure.

1 Like
3

Thank you very much