eep and brainvision definetrial

Robert Oostenveld r.oostenveld at FCDONDERS.RU.NL
Tue May 6 14:53:59 CEST 2008

Hi Susana,

Your problem might well be to the file being exported in a non- 
standard brainvision format.

On 27 Apr 2008, at 0:01, Susana Silva wrote:
> My questions are:
> -	In my position – someone who has eep files and brainvision files,
> what is the most simple option: try to use eep or brainvision (at the
> moment, I can use neither!)

Reading the eep files requires mex files, and that requires  
additional software from ANT (a librarry with the low0-level  
routines). Since that software is not open source, it is not possible  
to recompile the MEX file on your platform. You could complain about  
the file format with ANT and/or get another Matlab version (an old  
matlab on windows should work). As such, the brainvision format seems  
the most pragmatic solution to me.

> -	Can you give me an example of a trial definition based upon a
> brainvision file, let us say s1.eeg (data), s1.vhdr , s1.vmrk,  
> where ‘s33’
> (eventvalue) is the ‘Stimulus’ (eventtype)?

Example trial definitions are given in the documentation on the  
fieldtrip website.

> -	In case I can not do the trial definition, how exactly should I
> arrange my data so that they are equivalent to the output of  
> “definetrial”?

You should specify a trl matrix as cfg.trl to the preprocessing  
function, that matrrix is explained in the documentation on the  
website and in the definetrial function help.

best regards,

The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also and

More information about the fieldtrip mailing list