In the next version of MediaLab, there will be a key mapping function so you'll be able to assign different keys to be used for the different options on a scale response. Until then though, you are limited to 1 and 2. One alternative would be to use a 9pt or 12pt scale and you could use the extremes.. such as 1 and 9 or F1 and F12 respectively. You can hide the scale by using top parameter e.g., (p12,t1000). This would give the illusion of a 2 pt categorical judgement. The only other current alternative would be to use a button box or to create a custom HTML item. The latter might be a good way to go if you or anyone in your lab knows some basic HTML.