Valve Software believes that processing biometric data from players will become a fundamental aspect of future games. It's a hugely exciting idea: developers will be able to adjust gameplay according to how the player is feeling, and the way people interact in multiplayer titles could change irrevocably.
"When you look at the kinds of experiences we try to create for people, having access to [the] internal state of the player allows us to build much more interesting and compelling experiences," Valve's Gabe Newell reveals in a recent Steamcast.
"So we don't really think that that's in doubt; the question is really about when and in what forms that takes. Even very simple noisy proxies for player-state, like skin galvanic response or heart-rate, turn out to be super-useful and they're very much at the beginning of the kinds of data that you can gather."
Sensors that measure elements such as this could conceivably be built into next generation control pads, and Newell also points out that other biometric data could be harvested relatively easily, pointing to advances in webcam tech allowing developers to capture the "gaze" of the player and even measure pupil dilation.
Valve experimented with biometrics directly by introducing them into a special build of Left 4 Dead 2, with the developers surprised by just how much the game was changed just by sharing the data with other players - it added to the social experience.
"This was not something we were expecting and it's the sort of reason you like to invest in these kinds of research efforts is it's not only the things you expect it's the things that catch you by surprise," Newell says.
Valve took the various biometric data feeds and filtered them into what it called (no sniggering), the "arousal state". With the data beamed across to the other players, different behaviours began to emerge.
"When you were playing competitively we found that people were incredibly aggressive towards highly aroused players on the opposing team and were very defensive about highly aroused players on their own team," Newell explains.
In short, Valve had developed a system where sharing the players' feelings fundamentally altered how the game played out. The developers started to theorise on why this actually happened and came to some intriguing conclusions. While online gaming is a social experience of sorts, there are still many layers of anonymity to the experience: Newell likens it to the difference between email and chat. Sharing the biometric data took away some of that anonymity and changed the way that players interacted.
"This other thing is where you just have this bar on the side of your screen going up and down showing somebody else's arousal state actually seems to bring that sense of connection back, like your brain is flexible enough to actually internalise that as sort of a replacement for a bunch of the face-to-face cueing that we've lost," Newell says.
"So that's an example of something where we were completely caught by surprise as a side-effect of doing this biometric research... so we're going to do a lot more of that and we're sure that a lot of other people will discover a lot of other interesting things about it, but I think there's a lot of untapped opportunity in the biometrics space."
Stating that the future of this tech is very "science-fictiony", Gabe Newell also revealed that Valve is currently talking to a company that implants EEG (electroencephalography) equipment into people's skulls, providing a comprehensive flow of raw information about the body.
"It's about a $60,000 operation right now but it gives you fantastic data that you could use. Eventually you're going to reach the point where it's a reasonable consumer option, as strange as that sounds, and very much reminds me of science fiction stories out of the nineteen-fifties about embedded phones and things like that. But at some point there are going to be sort of increasingly accurate, increasingly sophisticated sources of data about what's going on in your body and in your brain."
While the roadmap for the tech is very much at its earliest stages at the moment, Newell is in no doubt that the principle of games reacting to the feeling of the people playing them will play a fundamental role in future software development.
"So, I think that that's just going to happen, in how we get there, what form factors that takes, how controllers and input devices change. That's the thing we don't know - the fact that it's going to occur I think is pretty predictable at this point," Newell continued.
"We're working on sort of industrial designs ourselves, like we did a mouse design that we've been using here internally. You could also do game controllers and things like that and even the primitive kinds of hardware that a software company does, we're working pretty well. So I would actually be surprised if the next generation of certainly living room devices didn't have some form of that."