Logging an RT with a window of time

[hfarmer]

Hi,

I'm currently trying to get a study set up using vizard 4 and am having a bit of a problem. I want to set up some code to measure reaction times after the presentation of a stimuli. However I want the program to move on to the next trial after 3 seconds regardless of whether a key is pressed or not. However this doesn't seem to be possible using the standard way of measuring reaction times given in the Vizard tutorial e.g:

		d = yield viztask.waitDraw() #Set Display time
		displayTime = d.time #Log display time
		d = yield viztask.waitKeyDown(None) #Log keypress time
		pressTime = d.time
		reactionTime = pressTime- displayTime #Calculate reaction time

Basically I want to know if there's a way to set up two parallel processes, one which is waiting for a key press to log reaction times and the other which just runs a timer and moves on the program after 3 seconds. Any help would be much appreciated.