Participants are going to view pictures. When they view each picture for a duration of 15 seconds, there would be a light bulb showing up for two seconds, if they press "SPACE" button, the light bulb would disappear. We want to record the time between the appearance of the light bulb and press of button. What would the code looks like in probes? How can I achieve it in Media lab?
Regarding the code to use probes, have you looked at the information in the first post of this thread: [url]http://www.empirisoft.com/support/showthread.php/375-Probe-Task-Samples-and-Documentation?highlight=probes?[/url] Have you tried to create your own MediaLab files; I usually find it helpful to take a look at files people have made and use those as a starting point for any troubleshooting I do. Feel free to either upload any such files to this thread or send them to me directly at [email]support@empirisoft.com[/email].
What is the full version number (i.e., 20xx.x.xxx) of your copy of MediaLab? You can find it by opening MediaLab and selecting Help>About MediaLab from the main menu bar.
Just out of curiosity, have you thought about trying this with DirectRT? Any tasks in which the recording of reaction times is desired is particularly well-suited to DirectRT.