BioSemi.nl

[leli]

Hi,

I'm quite new to the whole EEG stuff, so perhaps the answer to my question is trivial, but thanks for answering anyway.

I am recording EEG data with the BioSemi Active Two System and ActiView. When I look at the recorded data using the BioSemi BDFreader it looks okay. Each channel's 'track' is more or less centered around the accordingly labeled x-axis. When I import the data into EEGlab (version 8.0.3.5b) the signals are far out of the display range, i.e. far away from the x-axis of the according channel. When I remove the baseline (average) from each channel it gets a little bit better, but still the EEG-tracks are not centered correctly and are not as evenly spaced as with the BDFreader.

Why is that?
Am I doing something wrong?
What do I have to do to get rid of this problem?

I use
- the same reference channel(s)
- the same y-axis scale (100 mV)
- the same x-axis scale, i.e. time range

Lea

[leli]

Seems like I have solved the problem by myself. When the data are displayed via Plot > Channel data (scroll) just select Display > Remove DC offset. I hope that is really everything that was to it. Unfortunately this is not mentioned in any of the EEGlab tutorials.