I intern at an Adult Daycare facility and we have some members that have had a stroke and have lost their ability to speak or have become paralyzed and are forced to be in a wheel chair in addition to not speaking. One activity that seems to always stimulate these members in some way (a wave of a hand, bobbing their head, tapping their foot, etc.) is listening to music...either on the radio, or playing cds, or live musicians who come to perform at the facility. Hope this helps!