Getting an illimited amount of responses during a limited time-window

Lison

Hi all,

I'm trying to implement a complex span task in which participants have to perform a parity jugement task using the mouse response. This task needs to last exactly 12 seconds and to be self-paced in such a way that participants will answer to digits (even or odd, using mouse button) until the end of the 12 seconds, and I want to collect both response and time response for each digit of this parity jugement task.
I managed to handle the time issue by looping on an inline script item that get the current timestamp (clock.time()) and break when 12 secondes had passed. I also managed to handle the self-paced presentation issue either with an inline script (a canvas that show the digit and then a mouse collecting the response) or by presenting a sketchpad item for 0ms followed by a mouse reponse item.
Actually, the problem I encounter here is that running both of them at the same time does not work either because the time is not accurately counted or because collection of mouse responses is not accurate. I tried to loop on a parallel item containing the inline script with clock.time() and the sequence for digit presentation (sketchpad and then mouse response items), but no success...

I suppose that kind of task, and so that kind of issue had already been encountered by someone, but I didn't found any answer on the forum.

Thank you for your precious help !!

DahmSF

Hi Lison,

if i understand it you want to show a variable number of stimuli (with always one response) during a certain time (12s).

you may try it with an inline script like that:

seq=['put your stimuli here, the highest number you might expect']
timer_start=self.time()

while True:
    now=selt.time() 
    if (now-timer_start< 12000):
        t = seq[-1].show()
        key, time = kb.get_key(timeout=0)
            seq.pop()
    else:
        break

i wrote a similar script see http://forum.cogsci.nl/index.php?p=/discussion/2575/timing-of-responses#latest

Lison

Thanks a lot DahmSF !!
It works very well !!

DahmSF

You 're welcome

PD: Do not forget to save/log your variables in the script. And have in mind that loggers in the while loop slow down its performance

Chears
Stephan