Before Sony arrived at its final design for the DualShock 4 controller, the company trialled prototypes that measure skin conductivity to detect a player's emotions. In an interview with Stuff, Sony's lead system architect Mark Cerny says the company "looked at pretty much any idea [it] could think of," before settling on a modified version of the DualShock 3 design that includes a touch-sensitive center trackpad and light bar.

"Would it help to measure the galvanic response of the skin? We tried out a tremendous number of things - and then we went to the game teams to ask them what they thought they could use from the controller," said Cerny. As Sony moved away from including biofeedback technologies that could detect players' stress levels based on how much they sweat, the PlayStation 4 chief also admitted that older controllers had "not been ideal for first-person shooters." In a bid to improve that, Cerny says the DualShock 4 will feature improved triggers and joysticks that feel "extraordinarily natural." The controller will be available alongside the PlayStation 4 when it ships this holiday season.

"We looked at pretty much any idea we could think of."

Sony isn't the first gaming company to look into biometric feedback to improve its gaming experience. In May, Mike Ambinder, Valve's resident experimental psychologist, said the company had already begun conducting sweat-based experiments with the game Left 4 Dead, adjusting the gameplay according to a player's level of excitement. It also developed a modified version of Portal 2 that allowed users to control the game using only their eyes.