I have a related problem using DirectRT 2006. I plan to show a series of 15,000ms videos. On each trial, participants will have to make a response at some point during the middle of the video. However, I want the video to play for the full 15,000ms. I am looking to have two TTLs sent for each trial. I want one TTL sent when the video starts and another TTL when participants' make their response. In other words, I want to examine the data when the video starts (i.e., stimulus locked) and when participants make a response (i.e., response locked).

Is there a work-around when the response in the video is not fixed?