CursorTask Render Setting Changes Cursor Movement

[tahdah]

Hello,

To test the CursorTask application I've been using the SignalGenerator to create a 10Hz signal at 100uV. I've setup the Classifier such that Ch1 at 10Hz will make the cursor move to the left (assign a negative weight to it). However, the cursor seems to move to the left if I set the RenderingQuality to 'low', if it is set to high, the cursor moves to the right. Does anyone know why this happens?

Thanks

[mellinger]

Hi,

I cannot notice any difference between cursor movement in "high" vs. "low" quality rendering.
When I start BCI2000 with the CursorTask_SignalGenerator batch file, load "CursorTask_SignalGenerator.prm", then set "Filtering->Adaptation" to "0 0 0", and then click "Set Config" and "Start", the cursor will follow mouse movement with some delay, as expected. Changing "Application->RenderingQuality" to "low", and running again, the cursor will still follow mouse movement.

You will need to switch off adaptation, otherwise you will get a random direction of movement. Having the same amplitude in all target conditions will result in a baseline estimate that is basically identical to the constant amplitude, but may be slightly off due to small variances in amplitude that are related to how much of a full cycle is missing from the ARFilter's sliding data window. Variance adaptation will then enlarge those baseline fluctuations such that the cursor will move visibly, but in random direction.

Regards,
Juergen