Yeah, I wasn't talking about those (it would be pretty dumb to put them in). But I'm talking about killing normal things, like Clockwork Avians and Urban Droids, and not seeing anything change. I have a bit of a theory that, when you get hit, your concentration is actually reduced to zero, even if the level is reduced by 1. Because in my playthrough a few minutes ago, I got hit at max concentration, but I took six kills to get back to that level.