Technical Support regularly asks for raw data files for the purpose of troubleshooting. However, we often get data which BrainVision Analyzer is unable to open because file names were changed. This tip introduces the BrainVision data file structure.
BrainVision Recorder saves the recorded EEG data in three different files which are linked by internal references:
- The binary data file (.eeg) contains the recorded time series of your EEG.
- The header file (.vhdr) contains general information about the EEG recording such as the number of channels, amplifier settings, software filters, impedance values, references to the .eeg and .vmrk files, etc.
- The marker file (.vmrk) lists all markers present in the EEG data. It lists the markers together with their data point position, timestamps, marker type, description, reference to the .eeg file, etc.
As these three data files are internally linked, you should keep them together. Renaming the files – even identical renaming of this triplet – results in a mismatch between the references in header and marker files and the newly assigned file names. In case you want to rename your files, please contact us for instructions.
If you send us raw data, please send us all three data files, ideally compressed in a zip folder.