Srbox

pdias

Hello!

I am working on a task in Open Sesame using a Tobii 150 Pro Spectrum to collect pupil size and a srbox to collect the responses (RT and accuracy). The task is the AX-CPT and consist in responding YES every time you see the AX sequence on the screen and NO for any other letter sequence presented. I've assigned the bottoms 1 and 5 in the bottom box as the allowed key responses: the bottom 5 is for YES and bottom 1 is for NO and depending if the participant’s number is even or odd is the other way around. I have some doubts concerning the integration of the srbox in my experiment and would appreciate any help.

1)   Normally, during the calibration period I have to press space bar in order to move on with the calibration, however I am not using a keyboard, only the srbox. Can I perform the calibration using the srbox instead? How can I change this?

2)   In the practice loop, I have a feedback item which is giving me the correct RT but it is not computing accuracy properly (is coming out 0 all the time). Any idea why is this happening?

3)   In the output file from the experiment I’ve got no responses collected from the srbox, so although in the feedback RTs are apparently being recorded correctly, the output file is giving me nothing.

4)   If I am not using a keyboard, only the srbox, how can I can I stop or quit the experiment?

subject-0.csv

Attached you can find the experiment and the output file.

Many thanks in advance!

Patricia

AXCPT_Lab_V01_ET_2.osexp

sebastiaan

Hi Patricia,

> Normally, during the calibration period I have to press space bar in order to move on with the calibration, however I am not using a keyboard, only the srbox. Can I perform the calibration using the srbox instead? How can I change this?

and

> If I am not using a keyboard, only the srbox, how can I can I stop or quit the experiment?

In principle, it would be possible to hack into the Keyboard object such that it actually uses input from the SRBox. But I'm wondering: Is this really necessary? I'm assuming that the setup is such that the experimenter is present and has access to a keyboard, but that the participant only uses the SRBox. Is that correct? In that case, isn't it ok to use the keyboard for things that the experimenter would normally do, such as controlling the calibration and aborting the experiment?

> In the practice loop, I have a feedback item which is giving me the correct RT but it is not computing accuracy properly (is coming out 0 all the time). Any idea why is this happening?

I don't have access to an SRBox myself, but in dummy mode* this does work (although it always shows 0 or 100, because the feedback variables are cleared immediately after). It would probably be helpful to track the values of a few relevant variables, notably response, ProbeAnswer, correct_response, and correct. You can do this either by monitoring these in the variable inspector, or by showing the in the _Feedback item.

* While trying this I actually encountered and fixed a bug with dummy mode. So you cannot try this yourself for now.

> In the output file from the experiment I’ve got no responses collected from the srbox, so although in the feedback RTs are apparently being recorded correctly, the output file is giving me nothing.

In the output file there are two columns: response_Probe_srbox and response_time_Probe_srbox. Are these what you're looking for?

Cheers!

Sebastiaan

pdias

Thanks a lot Sebastiaan!

> In principle, it would be possible to hack into the Keyboard object such that it actually uses input from the SRBox. But I'm wondering: Is this really necessary? I'm assuming that the setup is such that the experimenter is present and has access to a keyboard, but that the participant only uses the SRBox. Is that correct? In that case, isn't it ok to use the keyboard for things that the experimenter would normally do, such as controlling the calibration and aborting the experiment?

You re right that this is not really necessary, so I will just go ahead and use the keyboard for that.

> I don't have access to an SRBox myself, but in dummy mode* this does work (although it always shows 0 or 100, because the feedback variables are cleared immediately after). It would probably be helpful to track the values of a few relevant variables, notably response, ProbeAnswer, correct_response, and correct. You can do this either by monitoring these in the variable inspector, or by showing the in the _Feedback item.

For me it is coming out zero all the time. Not sure why. I will do some tests and I'll ask you again in case they do not work.

Many thanks again!

pdias

Hi again!

So, I am still having problems with the integration of the SR button box and OpenSesame.

The problem is still that, although the srbox is collecting the RT just fine, it is not recording the accuracy. In the OpenSesame logfile we can see that there is a column called correct_response that especify which button was pressed during the task, but it does not confirm whether this response was correct or not. Even though it is important to see which buttons were pressed, I also need the typical accuracy binary data (i.e. (0 and 1). During the practice, where we give feedback to the subjects, I also have the same problem: it says all the time that the response is incorrect (even though it is correct), while it gives the reaction time normally. When I use the keyboard instead is working fine: I get in the logfile both reaction time and accuracy. My guess is that when I define the variable correct_response in OpenSesame, it does not understand that "1" is the correct and "2" is incorrect, because OpenSesame does not understand what these numbers are. I think this is the problem, because I have the same experiment working perfectly fine with the keyboard and the main difference is that the variable correct_response is set as letters (S or L), not numbers.

Sebastiaan, could you think of another reason why is that? Coud anybody else help me out on this?

Thanks!

Patricia

sebastiaan

Hi Patricia,

There was indeed a bug (multiple, actually) in the srbox plugin. But this should be resolved as of 3.2.8. Are you running the latest version of OpenSesame?

Cheers!

Sebastiaan

pdias

I think (almost sure) we are running the old version. I will recommend my colleagues to install the new version. Thanks a lot! :)

pdias

Hi Sebastiaan:

Just to let you know (so you can mark this as solved) that installing the new version of Open Sesame has solved the problem! Thanks a lot for fixing all the bugs with the srbox!

Cheers!

Patri

sebastiaan

Good to hear!