Hi Stephen,<br><br>I haven't used ERPlab so I'm not sure about the problem with that (and I assume getting this to work in ERPlab will be more straightforward than the solution I'm about to describe). If you have the accuracy information for each subject in a format that's readable by MATLAB, you can use it to iterate through EEG.event (or EEG.epoch) in EEGLAB and rewrite the events based on the accuracy. For example, if your events are coded with integers from 1-9, you could append a 0 on the codes for the incorrect ones and a 1 on the codes for correct ones (so a correct response in condition 1 would be coded 11, and an incorrect response 10). I don't know the exact format of your data, but it would involve something like this for each subject<br>
<br><div style="margin-left:40px"><span style="font-family:courier new,monospace"><span style="color:rgb(0,102,0)">% first load the accuracy data (using importdata(), dlmread() or similar function)<br><br>% go through each trial<br>
for i=1:length(EEG.epoch)<br></span></span></div><div style="margin-left:80px"><span style="font-family:courier new,monospace"><span style="color:rgb(0,102,0)">% append the accuracy code to the event code<br>% accuracy is a vector whose length is the number of trials, each element indicates whether that trial was responded to correctly</span></span></div>
<div style="margin-left:80px"><span style="font-family:courier new,monospace"><span style="color:rgb(0,102,0)">EEG.epoch(i).eventtype = [EEG.epoch(i).eventtype accuracy(i)];<br></span></span></div><div style="margin-left:40px">
<span style="font-family:courier new,monospace"><span style="color:rgb(0,102,0)">end;<br></span></span></div><br>Then once the events are rewritten, you can extract sets of epochs using the new codes (e.g., extracting only the correct trials for condition 1, etc.)<br>
<br>Best,<br>Steve<br><br><br><div class="gmail_quote">On Thu, Sep 20, 2012 at 8:14 PM, Stephen Hamilton <span dir="ltr"><<a href="mailto:sthamilton@ucdavis.edu" target="_blank">sthamilton@ucdavis.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">Dear all,</span><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">This is probably a very simple question with a straightforward answer, but I can't find it mentioned in previous posts. Apologies if I've missed it. </div>
<div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
I'm importing data recorded in Netstation (128 channel EGI system) into EEGlab so that I can reject artifacts using ICA. With Netstation, events are written into the .RAW files themselves, so I'm able to segment the data by condition very easily. However, I'm unable to distinguish correct trials from incorrect trials. When I try to import the event file given by Netstation, EEGlab doesn't like the fact that it's in string format. So, I've tried assigning events manually using the eventlist GUI provided by the ERPlab toolbox, but I'm unable to get it to read the accuracy information. This is, I think, because EGI/Netstation evaluates trial accuracy with TRSP events at the end of each trial and these evaluations are not tied to the condition labels themselves. If I open the Netstation event file the TRSP evaluation ("eval1" or "eval0") is provided at the end of the line for that event, I just can't get EEGlab to read it. It's probably just a matter of tying these together in the Binlister somehow, but I can't find an example of how this is done. </div>
<div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
Again, sorry if this has been answered before. Any help would be much appreciated! </div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
S Hamilton </div><span class="HOEnZb"><font color="#888888"><br clear="all"><div><br></div>-- <br>Dr. Stephen Hamilton<br>Postdoctoral Researcher<br>Language Processing Lab<br>University of California, Davis<br><br><br>
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