OpenViBE forum

Hi,

We're currently working on a set-up to collect data with a (slightly
modified) Emotiv EEG headset (version 1.0; note that we're still using the provided
amplifier).
For stimulus presentation we chose the "Presentation (Neurobs)" software (17.1)
and to collect the data we use OpenVibe (1.1.0).
Anyway, the presentation of stimuli and the recording of EEG data works
perfectly fine but it seems impossible to create a dataset that brings
both together - the triggers sent by presentation and the EEG recording.
We tried to use Labrecorder (1.11) and the LSL (which should do the job) in the
following set-up:
PC A was used to collect the EEG data using OpenVibe and also to run
Labrecorder during the experiment. PC B simply presented the stimuli
(via Presentation).
The resulting record (we use Matlab/EEGlab for the evaluation) actually
combines both signals but with different timestamps: the triggers sent
by PC B get marked with the uptime (NOT the system time) by PC A. This
is most probably done by Labrecorder.
Is/Was anyone struggling with a comparable problem/set-up?
Our aim is obviously to fix the timestamp issue. I'd be glad about any kind of help although I'm not in the position to change major parts of the setup.
If anyone worked with a similar setup using PsychoPy instead of Presentation, please contact me! I'm really curious.

Regards,
Marta

Hello, I am actually facing the same issue with Presentation and OpenVibe (sending triggers from Presentation to OpenVibe), did you find a solution to the problem? Thank you!

Hi Jessica,

if Presentation allows you to write plugins in it in some programming language, maybe you could use the plugin to send information towards openvibe. In case of markers/stimulations, what we call 'TCP Tagging' would probably be the way to go.

You can find a description of different ways openvibe can communicate with other programs here,

http://openvibe.inria.fr/overview-sendi ... -openvibe/


Best,
Jussi

Jussi,

I've read through the documentation multiple times and attempted TCP tagging from the Presentation side but without success.
When I use the tagging port 15361, and an active acquisition server, I do see signal entering Presentation but don't quite understand how to add a marker to the stream.

Signal entering presentation? I'm not quite sure what this means. Basically when Presentation displays some event, it should immediately send the event marker to AS. That happens by sending the id to that TCP port as the following consecutive 64bit unsigned integers,

0
event id or openvibe stimulation number
0

where the first 0 is padding and the last is the time, 0 means 'immediate'. You can use signal display reading from network acquisition box to see the attached markers.


Cheers,
Jussi