[Eeglablist] baseline correction

[bjj2909102003]

Hello,Angel.
Firstly, if you already had baseline correction, it was not necesssary to repeat. And even you repeated it, it did not bring big influences for your data.
Secondly,in my opinion, precompute ERPs was necessary for guys who did not have baseline correction.
In a word, precompute ERPs(baseline correction) is reasonable!



bjj2909102003
 
From: Angel Tabullo
Date: 2014-08-27 23:13
To: eeglablist at sccn.ucsd.edu
Subject: [Eeglablist] baseline correction
Hi everyone! I have a doubt regarding how ERP manages baseline correction in individual datasets and study data. 

Everytime I epoch individual data, extract the epochs that correspond to each experimental condition and save them in separate datasets, I use the "Remove Baseline" Tool ("rmbase") to sustract the mean value of the prestimulus period from the epochs.  However, EEGLAB offers another instance of baseline removal when precomputing channel measures for STUDY data. When you choose to precompute ERPs,  you can indicate the time window for the baseline correction. My question is: is it necessary to repeat this baseline correction step when calculating the grand average with the study data if you already removed baseline mean values from individual epoched data?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20140829/225e13e1/attachment.html>