I don't know if my fish know their names, but they do react when I talk to them. I play with them all the time, but I think they have started to associate my fingers with food. Unless my hand is completely in the water, my female betta will nip at my fingers since I've started finger feeding her. She bites hard, man! D: She like, latches on and doesn't let go until she realizes she missed the food.
I know they can see very well, since I can be clear across the room and they'll start wiggling. Sometimes Patriot notices me looking at him and he'll flare at me, even though I'm not even near his tank.