qEEG

Quantitative Electroencephalography (qEEG) is a procedure that processes the recorded EEG activity from a multi-electrode recording using a computer. This multi-channel EEG data is processed with various algorithms, such as the “Fourier” classically, or in more modern applications “Wavelet” analysis). The digital data is statistically analyzed, sometimes comparing values with “normative” database reference values. The processed EEG is commonly converted into colour maps of brain functioning called “Brain maps”.

1. Create a project

2. Upload files

Select your input files

Please note the following prerequisites:

• Upload a dataset in an accepted format by the qEEGt, which can be done via the web-based interface or through a secure FTP server. Data should be compressed as a tar.gz file.

• There are three input file formats currently available:

  1. The defined extension of the Brain Imaging Data Structure to handle EEG data (BIDS-EEG)
  2. A specific for the Neuronic PLG format (that require the .INF file) created by the Cuban Neuroscience Center
  3. The third one is for an ASCII file in a specific formatted TXT file

For this tutorial, we got the input file (PLG format) from HarMNqEEG Github page. You can also get data from the QEEGT-Toolbox GitHub page.

Note: The input file extension on GitHub is in capital. You will have to change the extension to lowercase to provide a proper input format.

Once your file(s) is uploaded, please select from the Files list:

3. Launch Task

Process the Launch Task steps, select the execution server and version of your choice and launch qEEG tool:

4. Task parameters

Set up the task parameters according to your analysis

5. Output

Once the task is completed, click on the output link:

CBRAIN generates a File Collection output, which you will have to change to MOD Collection. Please go to edit and change the Type to MOD Collection:

The results will be loaded in a tabbed display and show the results as 2D topographic maps or 3D tomographic images, depending on the data type.

The CBRAIN visualization tool opens a graphical user interface, in which all qEEGt results can be visualized: Either raw or Z spectra at the sensors' space at each frequency, synchronized with the corresponding 3D tomographic maps at the sources, for the narrow band model (high resolution spectral model).

Learn more about A Quantitative EEG Toolbox for the MNI Neuroinformatics Ecosystem: Normative SPM of EEG Source Spectra and the benefit of its integration in CBRAIN.