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Pupil Diameter and BCI2000

Posted: 22 Apr 2021, 18:20
by tjbosch
Hi All,

I am trying to use BCI2000 with my Tobii Pro TX300 to bring in pupil diameter as a state variable. My problem is that whenever the eye tracking data is logged, pupil diameter is only sporadically logged. Sometimes there's no data logged for each sample, sometimes only one eye and not the other, sometimes it's fine. In contrast, all of the gaze position data is logged fine for each sample.

I also tested the TX300 in MATLAB and it was able to log pupil diameter with each sample, so I'm curious why BCI2000 is only sporadically logging the data and how I might fix it.

Thanks in advance.

Re: Pupil Diameter and BCI2000

Posted: 04 May 2021, 09:04
by mellinger
Hi,

which BCI2000 extension are you using for the TX300? EyetrackerLogger, EyetrackerLoggerTobii3, EyetrackerLoggerTobiiPro, or EyetracerLoggerTobiiX?

-Juergen

Re: Pupil Diameter and BCI2000

Posted: 04 May 2021, 11:55
by tjbosch
Hi,

I am using the Tobii Pro logger. I was actually able to resolve this particular problem, but I now realize that I need pupil diameter to come in as an input channel, not a state variable.

Thank you.

Re: Pupil Diameter and BCI2000

Posted: 04 May 2021, 13:02
by mellinger
Would it help you if you could specify a state variable as an input to the SpatialFilter?

Re: Pupil Diameter and BCI2000

Posted: 18 May 2021, 11:34
by tjbosch
Yes, I think that would be helpful. I'm not sure if that's a parameter I can specify or if I would need to alter the source code.

Re: Pupil Diameter and BCI2000

Posted: 20 May 2021, 12:58
by mellinger
Yes, you would need to alter the source code of the SpatialFilter.