Synchronization with eye tracker (event transfer)

Authors: Martin Völker, Francois Tadel

This tutorial introduces how to transfer events from one data set to a second data set of a different type, which was recorded at the same time but with a different sampling rate. We will explain this on the example of synchronizing ocular data recorded with an EyeLink eye tracker (SR Research, Canada) with a second raw recording, e.g. EEG.


Eye tracking is useful to detect blinks, saccades, microsaccades and fixations during an experiment. Typically, the eye tracker software will itself mark the most common artifact types like blinks and saccades.

These artifact markers are very useful for the analysis of EEG / MEG data, since specific time periods which are contaminated with artifacts can be marked and excluded easily. To do so, we need to synchronize the eye tracker data with our EEG / MEG recordings.

This tutorial focusses on how to snychronize EyeLink data (.edf) with any other raw data type within brainstorm. Information about the EyeLink can be found at


For this function to work, you need specific markers, which are stored within both EEG/MEG and eye tracker data at the same time. The exact same number of this marker type has to be available in both data sets. They can, however, have different names.

Data import

First of all, the continuous MEG/EEG recording has to be linked to your Brainstorm database, if not already done (Review continuous recordings).

Then link the EyeLink .edf file in the same subject:

Event transfer

Now click on the "Process2" tab.


It is important to check if the event transfer was executed properly:

Additional documentation

Tutorials/EyetrackSynchro (last edited 2016-01-29 15:27:16 by FrancoisTadel)