[Solved] Adding a break after each randomised block - Run for all main blocks except the last one

apodim

I am trying to compile an AXB experiment with sound stimuli. Although it has been a steep curve, in the end I managed to have something that one could call a satisfactory result.

However, the experiment needs to present randomized blocks to participants. Lotje's solution in another thread seems to work perfectly for this. I even adapted it in order to introduce some warmup trials before each main block.

However I also need to stop the session for a small break after each main block. I could of course add three other loops and add them in the block sequence and have them run depending on the block_number as above, but the problem is I don't want it to run for a third time because at that time the experiment should end.

Maybe a way to implement this is by introducing a variable that increases after each block is run and should be below a certain value for the break blocks to actually run, but I am not sure of how to implement this.

I am also attaching the experiment for your reference.

https://filebin.net/8pj440bsxl2u0ep7/AXB_Experiment.osexp

Thank you in advance for any help.

Fab

Hi @apodim,

I couldn't download your task (for some reason, my antivirus blocks it) but based on your description, couldn't you add the break (e.g., a sketchpad instructing subjects to take a break) within the experiment_loop and insert [block_number]<3 as the "Run if" condition? That should ensure that the break runs after blocks 1 and 2, but not after block 3.

Does that help?

Fabrice.

apodim

Hi @Fab ,

Thanks for taking the time to answer!

The problem is that

the blocks are not presented in sequence but they are randomised in the experiment loop through the block_number variable. So block 3 might come first, second, or third.

Sorry about the task being on a hoster. I tried to upload it here several times but it keeps failing. Maybe the antivirus does not like its extension or the website it is hosted on. I am uploading it again on send (fork of the now defunct firefox send).

https://send.vis.ee/download/b7063779de97f4b3/#4aD-2iCsNF64O52-hLmDGg

Fab

Hi @apodim,

Ok, now I get it (I thought that your block_number variable was actually a counter).

Ok, so what you want to do in your case is indeed to implement a counter that gets incremented every time your block_sequence runs. It's actually easy to do. Since you're using javascript code instead of Python, I implemented the solution in Javascript.

Here's the logic:

(1) you set up a variable (I called it blockcounter) to 0 at the onset of the task:

vars.blockcount=0

(2) you increment that counter by one unit every time the block_seuqence runs:

vars.blockcount++

(3) you make sure that whatever sketchpad etc. you're using to implement the break in the task is set with a Run if condition : [blockcounter]<3.

That's it! Try it out. It should work. You can download my modification here:

https://www.dropbox.com/s/7p0whmjldjz33bh/AXB_Experiment%20Fab.osexp?dl=0

Hope this helps!

Fabrice.

PS: I think the forum doesn't let you upload the task directly because it is greater than 1Mb in size.

apodim

Hi @Fab,

Forgot to tell you that it works like a charm. It even inspired me to write a snippet to calculate accuracy.

Thank you very much!

Dimitrios

Fab

@apodim

Hi Dimitros,

Great, glad it's working!

Good luck with your experiment!

Fabrice.