Importing Grand Avarage from BrainVision Analyzer

Discussions
1

I am trying to import data from a couple grand avarages into BS but non of the export and import options work for me. Does anybody know in what format I have to export from Analyzer and what format I have to import in BS?

I am using:

  • Analyzer 1.05.0005
  • 61 + EOGh + EOGv + ECG
2

Hi,

We are not aware of this Amalyzer format. Could you please send us a little more details? Note that BrainStorm can read generic ASCII format files and use generic EEG montages. See the Tutorial for more info.

Sylvain

3

Hi Jorian, hi Silvain

I’m trying the same, importing EP grand averages from Brain Products Vision Analyzer 1 to Brainstorm 3 and I would be very intersted in your solution.

Analyzer 1 can export data in BESA format, and as generic ascii or bin, e.g. matrix which is structured as

ch_1, amplitudes 1 to n
ch_2, amplitudes 1 to n
.
.
.
ch_m, amplitudes 1 to n

The matrix may also be multiplexed, line delimiter ca be chosen as line feed or cariage return.

Thanks a lot
Denis

4

Yes, Brainstorm can import easily EEG recordings in BESA / ASCII format.
Right-click anywhere in the database tree > Import MEG/EEG…
In the import dialog box, select the last file format: “EEG: ASCII text”.

If you can export your Analyzer recordings in ASCII, you should be able to process them with Brainstorm.

You will need to import as well the definition of the electrodes (3D locations, names…) with the menu “Import channel file…”. Let us know if you have some trouble doing this.

By the way, if you have some Matlab functions to import Analyzer files, or the file format specifications, together with a sample file, send them to me. I would add support for those files in Brainstorm.

5

Hi Francois,

concerning import of Brain Vision Analyzer you will find attached expoerted file example of a auditory evoked potential (about 120ms, 32 Ch). Spontaneous EEG would be of the same structure, i.e. 1 channel in evrey colums, one time point in every row.

I tried to import that file in Brainstorm without success. Would it be possible to add a filter for direct import Analyzer 2 files to Brainstorm 3? Or to add a short description in the respective section of your manual? It would be great, because Vision Analyzer is according to my knowledge a common scientific tool for multichannel EEG processing.

Thanks a lot and best regard
Denis

6

Hi Denis,

You can import the BrainVision Analyzer files such as the one you sent me by selecting the file format “EEG: ASCII text”, and by selecting the following options:

  • Matrix orientation: [Time x Channel]
  • Skip header lines: 1
  • Amplitude units: microV (are those files really in microvolts? the values look really small…)
  • The other options depend on the file you are importing

To make this options selection easier, I added a format “EEG: BrainVision Analyzer”. It does exactly the same thing, but pre-selects the options in the dialog window.

Any other suggestions?

Cheers
Francois

7

Note for BrainVision / BrainAmp users:
A bug was found in the application of the channel gain, the amplitudes read where sometimes incorrect.
Please update Brainstorm for reading correct amplitudes from the BrainVision files.