"A very different study, in which robots interacted with stroke patients during physical rehabilitation exercises, yielded strikingly similar results. Introverted patients responded better and interacted longer with robots that were designed to speak in a soothing, gentle manner: "I know it is hard, but remember that it's for your own good," and, "Very nice, keep up the good work." Extroverts, on the other hand, worked harder for robots that used more bracing, aggressive language: "You can do more than that, I know it!" and "Concentrate on your exercise!"