I haven’t found a good way, but I have found a way.
The solution I’ve come up with involves two stimulus lists, code values, and correct responses based on code values.
Stimulus lists don’t get randomized, and if you use more than one in the same trial, the items are pared up linearly. That is, list 1 item 1 gets paired with list 2 item 1. list 1 item 2 gets paired with list 2 item 2, and so on. If one list runs out of items, it loops back around to the beginning.
Your first stimulus list straight forward. You add your expected items to it and set the appropriate code values. Your second stimulus list is less obvious. This will be a text stim list with as many items as are in the first list. The content of the text is unimportant (as we will display it the same color as your background), but it is important that the code values match up with the items in your first stimulus list. I would take advantage of the unimportance of the text and make it meaningful. For example, put the name of the stimulus as the text value, or whatever helps you properly pair items in the two lists.
Next, we will create a trial with two events. The first event is your stimulus, which is pulled from the stimulus list. The correct response depends on the code value, and the event ends after your specified time of 1000ms. The second event is a text event, displaying text from our second stimulus list. The color of the text should match your background color, so that it appears we simply erased the screen. The correct response for this is also set to depend on a code value. It’s important that you set up some sort of feedback to skip this second event in case the participant responds during the first event (assuming you want the trial to end on a response, that is).
This is a very brief overview of what I got to work–far from step-by-step directions. Maybe it will help… so far, it’s the only solution I’ve come up with.