Alternating images and variable delay
Hi,
I'm very new to the OS world and I need to run an experiment for an university project in Process interference and cove overlap(Koch). The experiment starts by pressing a Home key( like "G" in my case) that must be pressed until onset of an auditory signal(leaving the home key before the go signal leads to an error), keypress triggers a 500ms blank space followed by a sequence that shows a blue X or a red X in the center. I tried to create in the loop a [cue_color] variable with "blue" and "red" as parameters so that the sketchpad coul draw randomly between the two images of X but instead they are shown in sequence. That's the sketchpad script:
set duration keypress
set description "Displays stimuli"
draw image center=1 file="x_[cue_color].png" scale=1 show_if=always x=0 y=0 z_index=0
--
The X should be followed by a very fast target stimulus of 28 ms of two dots(14 each), first one centered and second one slitghly to the left or right; immediately followed by a mask to interfere with memory processing until a go signal it's played. The interval between the X onset and the go signal is fixed in 1300 ms, but the interval between X onset and target stimulus needs to be random picked between 4 time configuration, like
100/1200 ; 300/900 ; 900/300 ; 1200/100 . This means that the first configuration has a 100 ms blank space after X onset, 28ms of target stimulus, and 1200 ms of mask. The second has a 300 ms blank space, 28 ms target stimulus, 900 ms of mask and so on
Comments
Hi @Sazze,
I think your post is a little general for other users to be able to contribute. It seems you're after guidance on how to write the whole program for your experiment. My advice is to follow the various tutorials available for OS to familiarize yourself with the basics, so that you can work towards building your task.
The timing configuration you mention should not be difficult to achieve by coding these duration in the loop tables. Instead of setting the duration of sketcphads to "keypress", you should set it to zero and use a keyboard object right after your sketchpad.
Regarding the key release bit, you may find this thread useful: https://forum.cogsci.nl/discussion/206/solved-key-realease
Best,
Fabrice.