When something's bothering me, I obsess about it until I can find some resolution. So sticking with the theme of how to deal with my attention-seeking students, I realized that I instinctively back off when a student starts grandstanding. Invariably the student will pipe up with something off-topic and then go on and on and on, and I'm stuck at the front of the room, waiting.
Silly me, I don't have to be stuck. Jones' prescription for disruption is proximity.
So today, whenever a student got into "look at me!" mode, I purposefully, not quickly, moved toward the student. This happened three or four times today, and giving the student what they wanted -- my complete attention -- turned out to be not what they wanted at all. Every one of them faltered. By the time I got to their desk, they had stopped, which gave me the chance to put my hands on their desk, lean over, and say to them very quietly, "You're making a choice right now to act this way... I know you can make a better choice."
I'm also trying very hard, and it is very difficult for me, not to answer the backtalk, but to stare it down as I move closer. I'm have a little refrain inside my head: shut up shut up shut up, directed to me, not the student. It's helping.
Nevertheless, my two seventh grade labs today were chaotic, and I ended up having to send several disruptive students out as they were not following the safety rules. It's going to take a lot of hard work to get us where we need to be, but we're getting there.