Tutorial 9: Processes

This tutorial uses Sabine Meunier's somatotopy experiment, called TutorialCTF in your Brainstorm database.

The Processes tab in Brainstorm window is a very generic tool that can be used to apply a function or extract data from any set of data files (recordings or sources). Its main applications are: pre-processing, averaging, and data extraction.

Files to process

First, you have to select the files you want to process. You can drad'n'drop any node that contains recordings or sources from the database explorer to the Processes list.

• Click on sources file: Subject01 / StimRightThumb / ERP / MN:MEG(Kernel). Drag'n'drop it to the empty list in Processes list.

• Click on condition: Subject01 / StimLeftThumb. Add it to the list.

• Click alternatively on the Sources and Recordings buttons in the Processes tab. This indicates if you are going to process sources or recordings files. Observe that the number of files (the numbers indicated in brackets) changes according to the modality selected.
  
  

• Note that you can put almost anything in this list: recordings, sources, conditions, subjects, even the whole procotol. It will take recursively all the recordings or sources files that are contained in each node.

Process selection

• Select Sources. Click on Run. This big window appears:
  
  

• Processes selection: list of processes available for the selected data:

  • Z-score noise normalization: For each channel, compute the mean m and the variance v. For each time sample: substract m and divide by v. Uses the baseline definition.

  • Remove baseline

Next

This is the end of the first tutorial, based on CTF MEG recordings.

Other important notions are going to be introduced in a tutorial based on EEG data : clusters of electrodes, and statistical analysis. But please go again through all the importation / anatomy definition