“That’s where the truth lies, right down here in the gut. Do you know you have more nerve endings in your gut than you have in your head? You can look it up. Now, I know some of you are going to say, ‘I did look it up, and that’s not true.’ That’s ’cause you looked it up in a book. Next time, look it up in your gut. I did. My gut tells me that’s how our nervous system works.” - Stephen Colbert, 2006

Would you happen to know any papers with compelling evidence of this?