It did. You could do this in theory but it would be complicated and require many trials to cover the contingencies. Say you are using the 11 point scale you attached and the cursor is set in the middle (50) at the start. You would need 2 trials to follow the initial trial--one that shows it set at 40 in case "left" is pressed and one that shows it set at 60 in case "right is pressed". This is where is gets complicated. You then need to have each of those two trials followed by two such trials to handle the new contingencies. And then so, and so on. I can imagine this being done but it's hard to picture it being any fun.

I do think this would be a useful feature for DirectRT. In the mean time though (since it's currently not), I'd do it in MediaLab using the existing custom items that do this sort of thing. Or, in DirectRT, I'd go with a numeric key or mouse click that jumps to where they click (one time only) rather than trying to scroll with the arrow keys--they would be pretty easy.

Hope that helps.