Initializing Data into BIDS
Last updated on 2024-02-19 | Edit this page
Overview
Questions
- How do I get my data into a BIDS compliant folder structure?
- What does a BIDS folder structure look like?
Objectives
- Understand how to initialize your data into BIDS.
Creating a BIDS folder structure
Initializing data into a BIDS compliant folder structure will result
in individual subject folders that contain an eeg folder.
All of the EEG files for that participant will be stored within
sub-*/eeg/ folders.
To make the data compliant with BIDS, run the
bids_face13.m script in the Matlab Command Window:
A file chooser window will pop up when running the
bids_face13.m script. This file chooser is asking where you
want the sub-*/eeg folders to be created. Select the
project directory (Face13 folder) with the file
chooser.
Creating the sub-*/eeg/ folders in the root of your
project directory will create a folder structure that looks like
this:
Several files will be produced within each sub-*/eeg/
folder. All of the file names contain the subject number as well as the
task name and a suffix to denote the information that is saved within
that file. For example, the EEG recording data files have a suffix of
_eeg and are saved as .edf files.
Once this procedure is completed, your initialized data will be in
the BIDS standard (sub-*/eeg/) in the root of your project
folder.
Exploring the formatted text files with the participant folders
Now that the data sessions are BIDS compliant many of the data parameters are available within formatted text files. This makes it easy to explore the session parameters using a folder browser and simple text editor. Note that this also makes it very efficient for tools and platform to access relevant session parameters without having to read the large data files.
Digging down into the “BIDSification” process
The scripts used in this workshop use a forked version of the bids_matlab_tools EEGLAB plugin. We can explore the specifics of the process by examining the “bids_face13” script provided for this lesson.
The bids_export function is the tool that does the BIDS compliant data writing of an EEGLAB EEG data structure. Looking through this function provides the information about what inputs are required to generate the BIDS compliant data set, as well as what options are available to modify the output.
Next steps
Once the data are BIDS compliant, you are now ready to begin working with the data in the Processing data with EEGLAB tutorial.