Timestamps for the Cues of Graz MI BCI Stimulator

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faali002
Posts: 3
Joined: Sat Nov 04, 2023 4:17 pm

Timestamps for the Cues of Graz MI BCI Stimulator

Post by faali002 »

I am using the Graz Motor Imagery BCI Stimulator (provided in /openvibe/share/openvibe-scenarios/bci/motor-imagery/motor-imagery-bci-0-signal-monitoring.xml) for my experiment. I would like to know how to get the timestamps when the cues appear, as I would like to segment my signals based on these timestamps. I would be very grateful for your help.

Thomas
Posts: 211
Joined: Wed Mar 04, 2020 3:38 pm

Re: Timestamps for the Cues of Graz MI BCI Stimulator

Post by Thomas »

Hi Faali002,

If you want to segment the data online in OpenViBE, you can use the Stimulation Base Epoching box, which allows you to create chunks of signal upon receiving specific stimulations.

The cues are displayed by the Graz Visualization box upon receiving stimulations from the Stimulator box.
The stimulator box is a Lua scripting box, so you can open the file to see what stimulations are sent by the box.
Alternatively, you can use the Stimulation Listener box on the output of the Stimulator box, to log the stimulations.

If you want to do this offline, then you can record the data and the stimulation in the format of your choice with a Writer box, and the stimulations will be recorded timestamped so you can then use those.

Hope this helps.

Cheers,
Thomas

faali002
Posts: 3
Joined: Sat Nov 04, 2023 4:17 pm

Re: Timestamps for the Cues of Graz MI BCI Stimulator

Post by faali002 »

Thomas wrote:
Tue Nov 07, 2023 3:34 pm
Hi Faali002,

If you want to segment the data online in OpenViBE, you can use the Stimulation Base Epoching box, which allows you to create chunks of signal upon receiving specific stimulations.

The cues are displayed by the Graz Visualization box upon receiving stimulations from the Stimulator box.
The stimulator box is a Lua scripting box, so you can open the file to see what stimulations are sent by the box.
Alternatively, you can use the Stimulation Listener box on the output of the Stimulator box, to log the stimulations.

If you want to do this offline, then you can record the data and the stimulation in the format of your choice with a Writer box, and the stimulations will be recorded timestamped so you can then use those.

Hope this helps.

Cheers,
Thomas

Hi Thomas,

Thank you for your help. I used the Stimulation Listener to log the Stimulations. Is there a way to save the Stimulations as a Matrix with a box or something else?

Greetings

Thomas
Posts: 211
Joined: Wed Mar 04, 2020 3:38 pm

Re: Timestamps for the Cues of Graz MI BCI Stimulator

Post by Thomas »

Hi Faali002,

You can save the stimulations in a CSV file with the CSV File Writer box.

From OpenViBE 3.2.0 (although I suggest using the latest version of course), you can record stimulations only in a CSV file.
For this you need to right click on the CSV File Writer box and select inputs > input 1 > configure, and then change its type to Stimulations, then press apply.

You will see that the box then has only one input for stimulations.

Hope this helps.

Cheers,
Thomas

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