Is there a way to set a strict time limit on a group of trials? The "end" command in the "!meta" column seems perfect - except that it won't interrupt a trial when the time expires.

Basically, we want to record the number of spacebar presses a subject makes (each press indicating that an intrusive thought has occurred) during a set amount of time, say 3 minutes. To keep track of spacebar presses, we've set up a DirectRT input file that has a series of identical, essentially contentless trials that are each terminated when the subject presses the spacebar. The problem with using "end" is that a subject might press the spacebar 10 seconds after the 3-min period has ended, 10 mins after it has ended, or never - which is why it would be great if there was a way to put a hard limit on the amount of time that can be spent on this block of trials.

Any help would be greatly appreciated!

Quote Originally Posted by jarvis24 View Post
Yes, there is a way to do this in the 2006 version. See the attached "old or new" sample task for an illustration. It gives you 30 seconds to work on a set of math problems.

How it works:

You just create a comment column called !Meta. On any given trial you can create a time-based skip contingency by entering >tr:ms in the !Meta column--where tr is the trial you want to skip to and ms is the time (in milliseconds) after which you want to go there. The time-based skip is started at the onset of that trial and is executed when the time expires. The skip will occur no matter where DirectRT is but will wait until the current trial has been completed (it will not interrupt a session mid-trial).

Say for example, you want to give a set of math problems and skip to the end, or to a different section after 30 seconds. If the end is at trial #100, then on the first trial, enter >100:30000 in the !Meta column. DirectRT will skip the subject to trial #100, after 30 seconds from the onset of the first trial.