[Eeglablist] Biosemi importation into EEGLAB

[Guillaume Chanel]

Dear Edward,

concerning the reference question I suggest that you have a look at this 
adress on the biosemi website:
http://www.biosemi.com/faq/cms&drl.htm

This will help you understand what kind of reference you can apply with 
biosemi. To my experience the CAR or even the laplacian reference works 
quite well for BCI tasks recognition but your objective might be quite 
different. You can apply references directly in the EEGLAB software.

Concerning the epoching question... well I hope somebody else can answer 
because I have no idea.

good luck for the processing,

Guillaume Chanel

On 08/16/2012 08:37 PM, Edward Justin Modestino wrote:
> Dear experts,
> I have a few questions about importing my data into EEGLAB.
>
> (1) When I import the unreferenced Biosemi data into EEGLAB, either by:
>
>  >File > Import> From BIOSEMI BDF file (BIOSIG toolbox)
> OR
>  >File >Import > From BIOSEMI BDF and EDF files (BDF plugin)
>
> I get the following error in the MATALB command window:
>
> We highly recommend that you choose a reference channel IF these are
> Biosemi data
>
> (e.g., a mastoid or other channel). Otherwise the data will lose 40 dB
> of SNR!
>
> Reading BDF data in 24-bit format...
>
>
> *As the BIOSEMI data is recorded unreferenced, what do I do?  I may
> choose to take the common average reference (CAR) in EEGLAB after
> importation or take the CAR in another program before importing into
> EEGLAB.  What would I do in each case?  If I take the CAR prior to
> importation into EEGLAB, I will not have a channel for the CAR, so there
> still will be nothing to select.  If I import the BIOSEMI data
> unreferenced, how do I compensate for this warning in the command window?*
>
> (2) If I am importing BIOSEMI data that is already epoched, how do I
> proceed?  I cannot find this in the online manual.  Also, the event
> markers need to be fixed in the file, so I will be associating a text
> file to import the markers.  I know how to remove markers and to import
> new event markers. *But, how do I proceed with this data that has
> already been epoched _to let EEGLAB know it is epoched_?  Again, I
> cannot use the markers in the file.  I need to import the markers as an
> event file. *
> *_
> _*I appreciate any advice you can give me.
> Thanks,
> Ed
> *_
> _*--
> Edward Justin Modestino, Ph.D.
>
>
>
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