[FieldTrip] ft_read_sens on brain vision eeg data

[Robert Oostenveld]

Hi Nenad,

The Brain Vision Recorder software writes EEG data into three files, that are usually called *.vhdr, *.vmrk and *.dat. Sometime the latter one is caller *.eeg, and also *.seg might happen (after processing the data in Brain Vision Analyzer). But none of the three files contains electrode positions, therefore ft_read_sens won't work on them. 

EEG electrode positions are usually recorded with a Polhemus electromagnetic tracking device. Sometimes an optical tracker (e.g. Optotrak), acoustic tracker (Zebris) or camera-based system is used. However, there is not a single unique file format for the Polhemus recordings. Depending on the company from which you purchased the Polhemus tracker (usually an EEG system integration company, like ANT), you will get different software with it that writes teh position to different file formats. The ft_read_sens function understands some of the formats, but probably not all. Usually the files that are written by the software that comes with the Polhemus are in ascii, so you can edit (and convert) them with a text editor.

So rather than looking at the EEG amplifier with software, you should look at the electrode position recording device+software that you have been using. 

best regards,
Robert

PS it might be tha


On 12 Apr 2013, at 21:16, Nenad Polomac wrote:

> Dear all,
> 
> I would like to read sensors locations with ft_read_sens and it doesn't work. I have eeg data recorded with Brain Vision Recorder. It seems that that ft_read_sens doesn't recognize this file format. 
> Please help!
> 
> Thank you in advance!
> 
> Nenad
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