<div dir="ltr">Dear Fieldtrip Users,<div><br></div><div>I have a BVA-Fieldtrip problem. The average ERPs of Brain Vision Analyser are different from the ERPS of FieldTrip. It seems that in Fieldtrip a slow negative drift is added and peaks are more/less pronounced than in BVA (attached is a picture of the two different plots). </div>
<div><br></div><div>An expert FieldTrip User and I could not find a solution for this problem. I hope one of you has a suggestion for this problem.</div><div><br></div><div style>The individual trial data was exported from BVA (version 2.02.5859) with the following settings:</div>
<div style><span style="font-family:arial,sans-serif;font-size:13px">File extension: .seg</span><br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">Write header file: yes</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">Write marker file: yes</span><br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">Format: BINARY</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">Orientation: MULTIPLEXED</span><br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">Line Delimiter: CRLF (PC style)</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">Binary format: 16-Bit signed integer format</span><br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">Set resolution manually: no</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">Individually optimized resolution for each channel: yes</span><br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">Convert to big-endian order: no</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">Export all channels: no</span><br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">Export the following channels:</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">AF3 AF4 AF7 AF8 AFz C1 C2 C3 C4 C5 C6 CP1 CP2 CP3 CP4 CP5 </span><br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">CP6 CPz Cz F1 F2 F3 F4 F5 F6 F7 F8 FC1 FC2 FC3 FC4 FC5 </span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">FC6 FCz Fpz FT7 FT8 Fz Iz O1 O2 Oz P1 P10 P2 P3 P4 P5 </span><br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">P6 P7 P8 P9 PO3 PO4 PO7 PO8 POz Pz T7 T8 TP7 TP8</span><br>
</div><div style><span style="font-family:arial,sans-serif;font-size:13px">Created Using Component Version 2.0.2.5827</span><br></div><div style><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div>
<div style>
<span style="font-family:arial,sans-serif;font-size:13px">We used Matlab version 7.10.0 R2, and fieldtrip version 13-06-2013 (and tried a version from 2011).</span></div><div style><span style="font-family:arial,sans-serif;font-size:13px"><br>
</span></div><div style><span style="font-family:arial,sans-serif;font-size:13px">The scripts we used are read_analyzer_data and </span><font face="arial, sans-serif">timelockanalysis. This is the code we used for calling the scripts:</font></div>
<div style><font face="arial, sans-serif"><div>% read data into fieldtrip</div><div>cfg = [];</div><div><br></div><div>cfg.inputfile = 'pp10_A';</div><div>cfg.triggercode = 'S 20';</div><div>cfg.triggertype = 'Stimulus';</div>
<div>cfg.prestim = 1.2;</div><div>cfg.poststim = 1.7;</div><div><br></div><div>pp10_l = read_analyzer_data(cfg);</div><div><br></div><div>% check: compute ERP</div><div>% </div><div>cfg = [];</div><div>pp10_ERP = timelockanalysis(cfg, pp10_l);</div>
<div><br></div><div>%plot ERP</div><div><br></div><div>cfg = [];</div><div>cfg.layout = 'elec1010.lay';</div><div>cfg.xlim = [-0.15 1.7];</div><div>cfg.ylim = [-12.25 12.25];</div><div>% cfg.baseline = 'yes';</div>
<div>% cfg.baselinetype = 'absolute';</div><div>cfg.showlabels = 'yes';</div><div>cfg.interactive = 'yes';</div><div> </div><div>multiplotER(cfg, pp10_ERP);</div><div><br></div></font></div><div style>
<font face="arial, sans-serif"><br></font></div><div style><font face="arial, sans-serif">I hope you can help! </font></div><div style><font face="arial, sans-serif"><br></font></div><div style><font face="arial, sans-serif">Kind regards,</font></div>
<div style><font face="arial, sans-serif">Karen</font></div><div><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div><div style><br></div><div><div><br><br><div><br></div><div><br><div><br></div><div>
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