I’m working on creating an rsvp task investigating repetition blindness.
I was wondering if anyone knew how to manipulate the time each part of the rsvp string is presented. I would like to present a string of words and symbols (eg, &&&&****\dog%%%%\dog++++^^^^), but have the symbols and words presented for differing lengths of time.
For example, have the symbols presented for 125ms and dog presented for 100ms (or have the first presentation of dog presented for 100ms and the second presentation for 75ms).
This can be done by using a trial variable instead of a fixed time limit. You can create a trial variable by clicking on the Experiment menu and then choosing Trial Variables. A dialog appears. Click on the + icon to create a new trial variable. The Edit Trial Variable dialog appears. Make sure that the type is set to Number. In the Levels edit field, type the values that you want, e.g.
125, 100, 100, 75
Make sure that the values are separated by a comma. Click on OK when done.
To use the trial variable, edit your RSVP event, click on the Input tab, and change the time limit from Fixed to Variable, and then select the variable that you just created.
You can create as many trial variables as you need.