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# [solved] Feedback after large reaction time

edited January 2014

Hi, how can i apply a feedback only if RT is larger than the subject's avg?
Rotem

• edited January 2014

hi again
write in the feedback run if [response_time]>[avg_rt]

• edited 5:48PM

Thanks. The exp is working fine. I'm mot sure yet, but maybe i'll decide to add a brake (text display) every 50 trails- how can i do this?
One general question- what's the differense between the "run if" in trailsequence and the "show if" in an item?

• edited 5:48PM

you can use one of the following
1/ make every block with 50 trails and at the end of the block (outside the trail loop) add a sketchpad with a break text
2/ in the trail seq add a sketchpad with a break text and write in the run if [count_sequence]%50=49

as far as I understand run if control the the object itself (sketchpad etc) show if is for the display inside an object (text, shapes inside the sketchpad)

• edited 5:48PM

[count_sequence]%50=49
Is this going to work if i want the brake to appear after the 50, 100 and 150 trails?

• edited 5:48PM

yes

• edited 5:48PM

Can you please explain me this equation? What's the logic behind it and more generally, how do you know which variables to enter and how to built specific equations?

• edited 5:48PM

Hi Rotem,

As I explain in this post, the % operator gives you the remainder of a divison. Think of it as having 5 apples and dividing them equally over 4 children: this would leave you with 1 extra apple, hence `5%4 = 1` in Python.

The `count_sequence` variable gives you the amount of times the item `sequence` has been played, which in most cases equals the amount of trials that have been run (mind you, in Python we start counting at 0, so the first trial will have count 0, the second trial will actually be count 1, and so on). This means that calculating the remainder of `count_sequence` by 50 will result in giving you 0 on trial 0 (since 0%50=0), will produce 1 on the second trial (as 1%50=1) and so on until the 50th trial (which is counted as 49 in Python) that will give you 49%50 = 49. Hence the number 49 in `[count_sequence] % 50 = 49`.

In general, the equation is `[count_sequence] % Pnr = Pnr-1`, where Pnr is the number of trials you want between every pause.

Does that make sense?

Good luck!

Edwin

• edited 5:48PM

• edited 5:48PM

hi again, if i want the feedback to be [correct_arrow_response]=0 and [response_time]>[avg_rt], how can i apply them together?

• edited January 2014

By typing in just that, actually

`[correct_arrow_response] = 0 and [response_time] > [avg_rt]`

Also, you might wanna read this page, and in general it might be a good idea to search for answers on the documentation website before posting a question here. You'll have answers quicker, and won't have to rely on others. On top of that, you can find excellent tutorials there, which are very useful for a beginner.