Flicker paradigm/time limit and response (case 25709

[NN1]

I'm afraid I'm unsure how to correctly carry out the flicker paradigm on DirectRT, in that i would need the pattern of
image A(560ms),blank(80ms),B(560ms),blank(80ms),A(560ms),blank(80ms),B(560ms),blank(80ms),A(560ms)....etc
to continue in a loop until a key is pressed at which point it should stop the loop.

I understand how to display the images for the right amount of time OR until a response is given, but I am not sure how to display the images for the correct times without waiting for a response but also allowing for a response at any time - and that then that response would stop the pattern.

Many thanks in advance for any help with this!

[jason_reed]

First, you need to a row in your styles.drt file for each display time that also uses the automatic continuation feature. You will define the range of time in the MinMax field of a give row and then use an exclamation mark to use the automatic continuation feature (see the Automatic Continuation section of the DirectRT manual here for more information: http://www.empirisoft.com/directrt/help/_helpcontents.htm). For example, to display a stimulus for 80 ms, type this in the MinMax field of one row of the styles.drt file:

0-80!

Once you have created all the necessary rows in the styles.drt file, you can then assign the style code with the desired display time to each stimulus in the .csv input file by putting it in the stim cell between <> after the name of the stimulus (see the Hints section of this page of the DirectRT manual for an example: http://www.empirisoft.com/directrt/help/_helpcontents.htm).

You can then use the time field for each stimulus in the .csv file to define keypresses.

If you want to end the trial for a keypress on any stimulus besides the last one, use the skip feature as described here in the DirectRT manual: http://www.empirisoft.com/directrt/help/_helpcontents.htm