“The plan is to put me inside the fMRI scanner, apply burning heat, and see whether I can train myself to regulate my pain.”

That’s from reporter Erik Vance, who recently visited the lab of Stanford neurologist Sean Mackey. In a new feature for Nature, Vance describes Mackey’s research through the lens of being an actual participant (fair warning, this is uncomfortable to read):

Inside the coffin-sized tube of the fMRI machine, spasms in my back from its powerful magnet distract from the burning plate strapped again to my arm. On a screen above, I can see a squiggly line that represents the activity in a part of my anterior cingulate cortex. Mackey asks that I envision the heat as alternately searing and soothing. The aim is to master control of the line so that it (and thus my pain) goes up and down. As I switch between these visions the line on the screen twitches up and down.

It is surprisingly difficult. Willpower and meditation have little effect, and after two hours it is increasingly hard to make the stubborn little line move at all.

In this case, I think Vance’s first-person account is remarkably effective way to tell the story. Pain is fundamentally experiential, after all.

It seems like I’m hearing more and more about journalists who put themselves through odd or unpleasant situations for the sake of a story. Ted Conover became a guard at Sing Sing to find out what prison life is really like. Slate‘s Emily Yoffe, aka The Human Guinea Pig, has for six years written firsthand accounts, such as what it’s like to: be a daycare worker, a member of the Washington Nationals grounds crew, or compete in a matzo-ball eating competition.

As On the Media pointed out last year during an interview with Conover, this approach is usually extremely popular with readers. But when is going undercover unethical? Or worse — when does it become a gimmick?