Dual-task paradigm with visual and auditory probes, spoken and key-press responses

[jarvis24]

FYI, MediaLab actually has a function setup to do stuff like this. If you have access to it, you might be up and running faster. Check this out and see if it helps:

http://www.empirisoft.com/Support/showthread.php?t=375

Try also doing a general search on "probe" here on the support site and you might find some other useful links.

[quinnk]

Hi Blair,

The ML/DRT combo you suggested was useful, but now I have a new task and again find myself stumped. I did a search for "probe," but haven't found anything that addresses my problem.

Basically, I need to run the primary task through DRT, not ML, because each trial has multiple events that need to be time-controlled. More specifically, I have a sequence of 5 image stimuli with a total presentation time of 5 seconds. I want to add an auditory probe that has a duration of 500 msec and is presented at intervals of 750-1250 msec, to which participants will respond by speaking into a microphone. (Participants will not respond to the images.)

So, I need to present multiple image files and have auditory probes coming up at variable intervals, and I need to record auditory responses to each of these probes. Is this possible?

[jarvis24]

What I would probably do in that case is create multiple sound files with variable delays before the tone occurs. Randomly select one of those sound files on each trial *before* the images appear and specify a 0ms time value so there is no delay between the onset of the sound file and the onset of the images. Then use "RT:any" (or whatever) for each image and apply a min-max value of 0-1000! for the trial's style. That way, each image will only be on the screen for 1000ms, but will record the RT to the sound file if it occurs during its interval. I just made that up--does it make sense?