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Spatial nFC

PostPosted: Mon Nov 02, 2020 5:59 pm
by eddahaggerty
Hello,

I am trying to set up an nFC experiment with a vertical split. I have this setting selected and my two custom stimuli tucked underneath the nFC Procedure event umbrella, however, they still show up as a temporal presentation when running the experiment. Do I need to add another event to fix this?

I tried to attach images of my current settings but I don't seem to be able to on the forum.

Thank you,
Edda

Re: Spatial nFC

PostPosted: Wed Nov 04, 2020 3:35 am
by psykinematix
Hi,

The nFC Procedure actually automatically generates the stimulus instances, so you should not have to provide each of them explicitly. For a spatial nFC, the location of each instance will be defined based on the selected spatial splitting mode and the specified eccentricity. The value of the judged parameter for each instance will be randomly assigned so one instance will get the value specified by the method (i.e. the parent event of the nFC Procedure) combined with the pedestal value and the other instances set with the pedestal value only.

Have a look for example at the "Orientation Discrimination" tutorial: http://www.psykinematix.com/documentation/latest/Psykinematix%20Help/Lessons/Orientation_Discrimination_Lesson_1.html

If you tucked two stimuli underneath the nFC Procedure event then they will be considered as a single stimulus interval (with 2 sub-stimuli presented sequentially for each instance of the nFC procedure). Depending on what your experimental task is, you may have to structure your events hierarchy differently.

You should be able to attach images now by the way.

Hope this helps!

-- The Psykinematix Support Team @ KyberVision Japan LLC

Re: Spatial nFC

PostPosted: Thu Nov 05, 2020 2:51 pm
by eddahaggerty
Hello,

Thanks for your response. It seems like the nFC will not work for what I want to do then. I have two different stimuli (shown below) with which I want the observer to choose which one has a brighter center, so the judged parameter is not the only difference between the two. Is there a procedure type that allows me to do something like this?

Screen Shot 2020-11-05 at 1.47.21 PM.png
Screen Shot 2020-11-05 at 1.47.21 PM.png (70.47 KiB) Viewed 15181 times


Thanks,
Edda

Re: Spatial nFC

PostPosted: Wed Nov 11, 2020 9:04 am
by psykinematix
Hi Edda,

It looks like a discrimination procedure is what you want to implement.

Have a look for example at the "Contrast Sensitivity" tutorial: http://www.psykinematix.com/documentati ... son_1.html

Hope this helps!

-- The Psykinematix Support Team @ KyberVision Japan LLC

Re: Spatial nFC

PostPosted: Thu Nov 12, 2020 4:19 pm
by eddahaggerty
Hello,

Is there a way to display two different stimuli at the same time using this procedure or do I have to somehow combine both into one? I tried using the shift(x,u,v) operation outlined here: http://www.psykinematix.com/documentati ... tml#custom to get the different circles off center, but it doesn't seem to be having any effect.

Thank you,
Edda