Control an animated robot mouth light via Visemes?

Hi!

So I’m trying to make a robot avatar that has a light activate in its mouth when it speaks

I’ve made an animation for the light turning on and off, and I’ve successfully got it working via the FX anim layer

Unfortunately, I don’t seem to be able to get it to activate via Visemes. I’ve also tried using GestureLeft to get it to activate when I make a fist, but it doesn’t work

Can you “read” animator parameters in this way? The docs seem to imply that you can, I must be doing something wrong!

My setup is below, and again, it blinks on and off constantly if I take the transition condition out