Millisecond Forums

How do I notify subjects when their response is late with a "ding" noise and collect that data?

By Anoushka Shahane - 8/1/2014

Hello everyone!

My task is quite simple: I flash letters on the screen and if there is an A followed by an X, that is a target so subjects click the left mouse button. If it is any other sequence of two letters, it is a non-target, so subjects click the right mouse button.

What am I trying to do in Inquisit is the following: when subjects respond with their clicks, if they are too late there should be a "ding" sound that comes (so the ding should only sound if they are late). I also want to collect this data to know when they were late and on which particular trials.

Any insight into how to program this would be appreciated greatly. Thank you!
By Dave - 8/1/2014

This cannot be answered generically. It entirely depends on how you implemented the rest of the task. Among other things, you need to spell out

- How exactly you've realized the letter presentation: Is the letter stream presented in a single <trial> via its /stimulustimes? Is it presented by running multiple <trial>s each presenting a single letter in quick succession? etc.

- What exactly is a "late" response supposed to mean?


To at least give you a *basic* idea, here's an example for one simple scenario:

/ latecount = 0

<block myblock>
/ trials = [1-10=mytrial]

<trial mytrial>
/ stimulustimes = [0=a; 100=x; 1100=systembeep]
/ inputdevice = mouse
/ validresponse = (lbuttondown, rbuttondown)
/ correctresponse = (lbuttondown)
/ responseinterrupt = immediate
/ beginresponsetime = 100
/ ontrialend = [if (trial.mytrial.latency>1000) values.latecount+=1]

<text a>
/ items = ("A")

<text x>
/ items = ("X")

/ columns = [date time subject blocknum blockcode trialnum trialcode response latency correct values.latecount]

By Anoushka Shahane - 8/2/2014

Hi Dave, 

Thank you so much for your detailed response. I appreciate it greatly. The letter streams are presented in distinct trials which are branched together and based on your response, I can see that the "lateness" can be flexible. I was aiming for having the response window open as soon as the stimuli is flashed and have it close after 200-300 ms, which, if I am not mistaken, can be implemented depending on when the systembeep is triggered. 

Thank you very much once again, this was very very helpful!
By Dave - 8/3/2014

Yes, can make the "lateness-window" as wide or narrow as you need / as is applicable to your script. Let me know if you encounter any specific problems when implementing it.