Any ideas on how to set MediaLab for categorical judgements? I only want my participants to rate videos with a "yes/no" answer, ideally usign the arrow keys. I tried the "scale response" but it seems this way confines me to the numboard and specifically have to use keys #1 and #2. Any alternatives? Note: reponse has to be by keypress not mouse, as I'm looking at reponse latency too (but not to the millisecond).