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I am having some doubts whether I understand correctly the concept of static component or not.

I am designing an experiment where I am presenting images for certain durations and once an image is gone the participant will have to submit a response.

I am using the builder for this and usually at the end I go on the coder view to make some minor alterations (randomise inter-trial durations etc)

So in the builder, I start a loop where my first routine has an ISI component for 0.5 seconds, then I add an image ad 0.5 seconds, a second routine in the loop records the key response.

What I want to do, in order to avoid lag, is to load the image during the ISI and then display it after the 0.5 seconds have passed. I am ok with the condition file and how to use parameters as variables. So in the Image entry I use $image (as declared in my excel file), I also declare that I want this image to be set "during trial:ISI". Does this do what I have in mind? Load the image during ISI and flip it once ISI finishes?

Secondly, do you think it will be more efficient to have the ISI and the image in different routines inside the same loop?

If you have any other suggestions on how it can be done in a more efficient way please let me know.

Thank you.

Lazaros
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1 Answers1

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(1) Yes, this is the correct way to use the ISI to pre-load an image.

(2) No, there is no need to split across different routines.

(3) You should avoid going "on the coder view to make some minor alterations". Once you make changes there, the Builder view can't be utilised any more. It is very likely that you can achieve what you want by putting code within a Code Component in the Builder view, so you don't have to abandon the advantages of the graphical interface.

Michael MacAskill
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  • Thank you Michael. To be honest, I have only recently started to appreciate the value of the code component. I will definitely follow your advice on that. Regarding the ISI, do I have to make any code changes or does it load the image automatically, again the image is set to be presented at 0.5 seconds via the builder interface using the $image as file and $duration for duration in seconds. That is the part that is still grey to me. Thank you. – Lazaros Nov 04 '14 at 09:07
  • Mike is quite right with all of the above. In fact, for (2) I think it's more extreme right now - I think the system is failing if the component is in a different Routine to the Static Component. This should work either way but it's a bug. – Jon Nov 04 '14 at 09:21
  • You don't need to add any further code if you're just updating images this way. It will handle that part for you – Jon Nov 04 '14 at 09:22
  • Thank you guys. I think I am covered. I also did some testing with big image files and it does make a difference if I use ISI or not. – Lazaros Nov 04 '14 at 12:57