In my personal experience, tongue fasciculations can very well be felt. Not like the usual body fasciculations, but they feel like little electric currents on your tongue and this can drive you CRAZY. There are some fasciculations that can hardly be felt when the affected body part is not touching any surface, but are very obvious if you have a "counterpart". To feel tongue twitches , I needed the contact with my mouth roof, otherwise it felt like licking a battery (not that I do this a lot, I have other hobbies..). Ellbow/forearm region is another part. But it seems that anxiety can trigger tongue fasciculations more than one might know. I had an ongoing hot spot of a tonge fasciculation when I had my tongue pierced, and the piercer asked if I was nervous. I said no, this happens to me once in a while. They do lots of tongue piercings every day and see those little flickering spots a lot in stressed people.