Place a time limit on a task?

[sjlee0623]

I would like to create a compound stimulus trial in which a movie plays, and is followed by a picture. I would like to record a RT (from the point of the picture onset), clear the screen once the RT has been recorded, but keep the cleared screen up for a duration of time. The point being that each trial has to have a fixed duration (trial referring to the compound stimulus of movie + picture + response + cleared screen).

I currently have this set up as a compound trial that shows the movie, then puts up the picture (rt:1,2,full,clear-1). I'm using this along with min-max! to automatically advance to the next trial at the end of the max period (e.g., 6 sec - even if there was no response). I thought this would make it such that the total time of the compound stimulus trial should not exceed 6 seconds. But upon testing, I see that the movie will play, then the second picture and response element will stay up for 6 seconds... creating a total trial length exceeding 6.

The problem with using this method is that I have over 100 of these compound trials, in which the movies are all different lengths. Yet, I want each compound trial up for a fixed duration. The way I have it set up at the moment, this would require a new style to be created for each trial, with the appropriate min-max defined based on each movie length (max = 6000-movie).

I was looking in the forums for a different way to do this, and I came across meta! This would be the perfect solution if meta was capable of interrupting a trial (>tr:6000). I could then set a very high max (all trials using the same style), and interrupt the trial after 6 seconds (counting from the onset of the movie).

I'm running DirectRT 2006.2.28. Is there a way (using meta, min-max, or any other feature) that I can do this?

Nice, I always enjoy seeing an answer arrive before I do

For anyone who's interested, this key press tracking feature in MediaLab is described in the following post:

www.empirisoft.com/support/showthread.php?t=817

But you are very right about that limitation in the DirectRT meta function. I think it's kind of annoying and will put it on the to-remedy list. Currently, meta functions only kick in between trials. It's because the timing loops within trials are so important, we avoid anything that could disturb them. Consequently, meta functions are assigned a lower priority such that they can only function between trials. We may have a way to change this in the next version so you can do it either way.

[jarvis24]

You have reinforced the point that the duration meta command would be especially useful if it could kick in during the trial rather than between trials. I see your point about the variable length movies and the fact that you could have to create different styles for each. As cumbersome as that is, I don't see away around it for this particular application--not if you want to keep the trial durations constant with variable length movie files. Hmm.

[Pamela Allen]

In the posting 9/12/2007 it was mentioned that the next version of DirectRT would possibly allow the !meta function a higher priority such that it would be able to function not only between trials, but would be able to interrupt a trial after a given amount of time.

I am using DirectRT version 2008.1.0.13
Does anyone know if this version allows for this? From what I have tried, it does not appear to, but I could be missing something so any confirmation would be helpful.

My basic goal is to run open ended trials (rt:text) where participants have 15 seconds to enter a response. If they do not enter a response within that amount of time, I need the program to automatically proceed to the next trial after displaying the message "Please try to respond faster!" If there are any other suggestions as to how to accomplish this, that would be great as well.

Thank you for your help,

PA