It's only something that you can really judge.
For me Cataplexy doesn't occur while alone, unless of course I'm watching some super funny show or movie, or perhaps my cats are being way too cute.
For me the sensations are anything from a flickering of the muscles (in head down to toes, and/or any part there or between), it can be like a convulsing or spasm sensation, it can be like being frozen or a pause button was hit and my body just won't respond physically, sort of a rag doll like feeling all the way to being quite literally entirely physically paralyzed (just breathing, hearing, seeing [sometimes not entirely clearly due to position or eye/lid spasm] and completely thinking through out the ordeal).
When I was young, when I'd be tickled in my belly intensely, laughing real real hard; my arms would not lift no matter how hard I tried to lift them, but I could remain laughing and forcing my torso from its center to turn and/or roll from side to side, but the arms would just not respond.
Triggering it in your own mind, seems different, but who really knows?
The best of luck, there are many post within the site regarding this.