This was a technique I used in one of my papers. Two-alternative forced choice tasks typically use digital responses (keyboards, button boxes, etc.). These create the situation where people could be biased to make a choice, especially if one choice is more likely than the other. With the use of analog triggers, we can track response preparation and conclude whether this does or does not happen. Plus, with the continous signal, we can decode thigns like response speed, how much time participants pend moving the triggers once initated, did they reverse their choice midway (see trial 15). Game controllers affords researchers a rich set of data, while itself being a very affordable solution!
This response input method was implemented in Python using threading.