how to record RT while stimulus is ongoing (case 6715)

[Zeke]

Hello All,

Maybe this is an obvious one but I would like to start recording an RT during the middle of a stimulus. Here's the set-up:

The stim consists of 9 images which total up to a cumulative 900msecs (there are 3 50msec images, 3 100msec images, and 3 150msec images- these are randomized within the 900 msec window).

One of the images is a "trigger" which contains a target change that the participants are required to identify- I want the RT clock to start when this trigger image appears. Concurrent with the onset of this trigger image is a 60msec tone. The caveat is that there can be anywhere from 1 to 7 "distractor" images left to present after this trigger image is shown.

I have my input file ignoring the images that come after the trigger image, asit is very unlikely that any participant will identify the target in the trigger image in the 100 to 600 (or so) msec before the remaining images are all displayed (not really relevant, but they need to press the "z" key if the target is a horizontal line, and the "m" key for a vertical target). I can accomplish this by subtraction, but think it would be super-nifty to learn how to actually make it work in DirectRT.

I've included an excel sheet with examples- Thanks mucho mucho!