Producing Markers and Sending them Via LSL


#1

Hi,
I’m trying send muse EEG raw data via LSL and record it with lab recorder so that I can use them in BCILAB/EEGLAB. I can send the muse output file via LSL and record it with lab recorder. But I don’t know how to produce and then send the markers for the events. May I ask if any one knows if there is any program or way to create and send markers via LSL? Because without the marker stream I cannot use my EEG data for analysis and …

I would really appreciate it if someone can help me with that.
Thank you!
Donia


#2

One can use SNAP (developed along with LSL) to generate event markers: https://github.com/sccn/SNAP However, the LSL option in muse-io doesn’t work properly. There is a problem with the timestamps when other datastreams (such as event markers) are recorded simultaneously with the EEG stream, even with the accelerometer data from the Muse itself. See https://code.google.com/p/labstreami…s/detail?id=35 Because of the issue described on this thread, it’s currently not possible to record any other data streams simultaneously with the Muse EEG stream when the --lsl flag is used with muse-io (even the accelerometer stream from the headset cannot be recorded with the EEG stream, as the timestamps are not synchronized). This is a problem from the LSL implementation in the muse-io The current hypothesis is that the headset stream is dropping out frequently causing errors in LSL. My current workaround is sending OSC out through muse-io and forwarding these OSC messages to LSL using a dedicated python script. Then one can use LabRecorder to record the event markers from SNAP with the forwarded EEG data.


#3

Hi!
Thank you so much for responding!
Yes, actually I saw https://code.google.com/p/labstreaminglayer/issues/detail?id=35 and posted a question. And I got the same answer that you said there. (I think it was you who replied to my question there. :slight_smile: thanks again).
Now may I ask again please here too that how do you generate the event markers in SNAP, are you writing a code? Also how do you forward the OSC messages to LSL?

Thank you very much!