The character Rust, played by Mathew McConaughey in the TV series True Detective, Season 1, has quite a number of quirks or ticks. One of them is to check his pulse at times. His hand reaches out to feel for his cartoid artery for a while.
I have noticed that he is shown to do this exactly after a rough moment. The first time he does it is after his locker room altercation with Marty (when he threatens to break Marty's wrists). He again does this while accompanying Ginger (one in the biker gang called Iron Crusaders) on the black neighbourhood snatch. And if IIRC, he does it a third time right after he has had tempestuous sex with Marty's wife.
Why does he do that? Is it a way to subdue himself or something else?