Sooo I can cause what honestly feels like a small and constant electrical current flow through any part of my body. If I center this feeling on my chest it is easily more prominent than anywhere else with my head being second. Extremities are dead last. If I am hooked up to a heart monitor I can make it freak out at will. Any location I focus it on tends to want to tense up.
I like to tell people this is the result of me grabbing onto a metal item when I was younger that was still hot. Couldn't let go for a solid 6-10 seconds, can't say exactly how long. What I am able to do feels very similar.