What do you do if you're thinking about spending $2 billion on a hot virtual reality company? Well, if you're Facebook CEO Mark Zuckerberg, you go experience cutting-edge virtual reality for yourself.

Weeks before Facebook announced that it had acquired virtual reality gaming headset manufacturer Oculus Rift, Zuckerberg made a private visit to Stanford University. He was there to see one of the country's leading virtual reality experts, Associate Professor Jeremy Bailenson.

Bailenson directs Stanford's Virtual Human Interaction Lab, where he conducts variety of virtual reality experiments designed primarily to understanding VR's impact on human behavior.

Image: Stanford University / Kornberg Associates Architects

When we first spoke a week ago, Bailenson mentioned that he'd recently had visits from social media companies, "I’ve had some pretty major players in the field of social networking come to my labs in the last few months to find out how they can make social networking feel more like a party.”

One of those visitors, Bailenson revealed after the Oculus Rift announcement, was Mark Zuckerberg.

"Mark Zuckerberg came to visit the lab on Feb. 13 with Cory Ondrejka, a vice president of engineering at Facebook," wrote Bailenson in an email to Mashable. "We spent two hours together, 30 minutes touring the lab, and 90 minutes talking about the psychology and applications of VR. I gave each of them a copy of my book, Infinite Reality, and I pointed them to specific chapters on how VR could be used to improve education, help the environment, and teach altruism."

Zuckerberg and Ondrejka also both experienced immersive VR, including Bailenson's Virtual Reality "Pit."

You can see what Bailenson's lab looks like and the kinds of experiments he conducts, including the one Zuckerberg likely experienced, in this PBS NewsHour clip (above), which aired last year. Fast forward in the video to 2:31 to see the PBS host take part in Bailenson's "Pit" experiment, which virtually places the subject over a floor that suddenly drops away to reveal a 30-ft deep shaft. The subject is left standing on one narrow piece of wood.

While there are no photos or video documenting Zuckerberg's experience with the VR pit, Bailenson, who has used the Oculus VR headset in his experiments, described in an email Zuckerberg's reaction, "He definitely was 'high presence,' meaning he reacted as if the simulation was real."

Clearly, Zuckerberg's virtual reality adventure left an impression on the Facebook CEO.

Mashable has contacted Facebook for comment on Zuckerberg's visit. We will update this story with its response.