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Stop signal task creation


We are trying to implement a stop-signal task in builder, in which a stop-signal appears on 25% of trials. the rest of the trials are a choice reaction time task.
we want the stop signal delay (time between the Go signal and subsequent response) to be adjusted by fixed increments (e.g. 50ms) depending on whether the person was able to successful stop or not on the previous stop trial. We are wondering how to implement the staircase method for this situation. Ultimately we want 50% successful stopping in the Stop trials.
Because the Stop signal does not occur on every trial, we need to integrate the staircase loop within the main trials loops (where both go and stop trials are selected from either a pre-determined list, or in random order).

We had a go at it (please see attached). We haven’t even got to the stage of finding out the way to change the stop signal delay. At the moment, we are stuck in how to select different routine in each trial. We saw this post, Randomize 3 Routines Containing Scale Component, but are unable to solve this issue.

thanks for your help

SRT2.psyexp (23.0 KB)
Book1_origi.xlsx (9.2 KB)


Hi, did you manage to solve this problem??


Hi Alessio,

Are you just interested in how to select a routine?
If this is the case, you can see how we did it here, Provide feedback (mean RT and number of stops) after a block in a SST task.
Note that this sample is a simple SST.



I was interested how to integrate the staircase loop with the trials one, and then how you did modulate the Inter stimulus Interval between the visual and auditory stimulus!
I will have a look at the link you sent me, and maybe then be back to you.
But thanks for your attention and help until now, really appreciated!


I had a look at the link, but unfortunately I don’t really understand which solution proposed by Jon you used for your task. Did you collapse the Go and Stop trials?