Remember the Steam Box that was rumoured to be announced at GDC? The one that was supposed to sit under your TV and use biometric signals to shape your games? We've been squeezing the truth out of Valve.

“Yeah, of course it's a big story and obviously, it doesn't surprise me that you asked the question.” said Doug Lombardi, Vice President of Marketing at Valve, when quizzed about its existence.

“We've always been very public with wanting to play with biometric feedback and new input devices, and yeah we are playing around with that stuff. We do think we have an interesting idea there and we're pushing in different directions with that.”

But does the Steam Box actually exist? Doug almost denied it: “But all that is a long way from Valve shipping a hardware device,” he said.

The idea of biometric feedback in games still seems to be a priority for Valve. We spoke to Gabe about it in September 2010 .

“We think there's something there... Is it something worth spending our time and having fun with? Who knows? The future will tell us that," says Doug.

"We learned in Left4Dead that by connecting people to machines while playtesting we were able to - very matter-of-factly - measure what got them excited, what got them frustrated, rather than: 'Well, he looks a little pissed off right now so he must be frustrated.'

"We spend a lot of time talking about scheduling peaks and valleys and the experience: players don't get battle fatigued and they don't get bored. And the two things offset each other; you want to have a little quiet boredom like in a monster movie and you're like “OK, it's been quiet for too long“ and then all of a sudden “EEK EEK EEK! Oh shit! Here it comes!”

You can read the full interview in an upcoming issue of PC Gamer UK .