One of the ways in which PC gaming saviour Valve is looking to innovate is in the field of biometric input, with the Half-Life creator apparently now testing various control methods that use eye-tracking and take data from sweat sensors so the software knows when you're panicking or at the limits of your skills.
According to Valve's in-house experimental psychologist, the company's already implemented a biometric sweat sensor that takes data from the player's pores and sticks it into a customised version of Left4Dead. One of the tests used this biometric sweat-based stress test data to amend enemy attacks, giving players less time to shoot their way through enemies when it sensed they were stressed.
Sci-fi puzzle game Portal 2 has also been adapted to be controlled via eye movement, with Valve psychologist Mike Ambinder saying: "It’s still experimental, but it worked pretty well, and we were pleased with that." [Venturebeat via The Verge]