Could the controller of tomorrow read our minds and be able to adjust gameplay experiences when we get bored, sad, or excited? That future might not be too far away. Engineers at Stanford University today say they have uncovered the "next step in interactive gaming" through a controller that gauges the player's brain activity and adjusts gameplay experiences accordingly.

　　Stanford's prototype controller was created by Corey McCall, a doctoral candidate of electrical engineering professor Gregory Kovac. McCall modified a standard Xbox 360 controller by popping off the back panel and replacing it with a "3D printed plastic module" that features sensors that measure a player's heart rate and blood flow, as well as rate of breath and how deeply a person is breathing. A light-operated sensor can track a second heart rate measurement, while built-in accelerometers measure the rate at which you shake the controller.

　　At the same time, proprietary software gauges the intensity of a game--in this case the simple rhythm/racing game Audiosurf Overture. Using physiological data gathered using the controller, researchers can then assess a player's overall level of mental engagement with the game.

　　"You can see the expression of a person's autonomic nervous system in their heart rate and skin temperature and respiration rate, and by measuring those outputs, we can understand what's happening in the brain almost instantaneously," McCall said in a Stanford news release.

　　McCall first demonstrated his controller at the Consumer Electronics Show (CES) in Las Vegas earlier this year. He says that by gathering such biometric feedback, developers can create more immersive worlds by, for example, adding new enemies to a level when a player begins to feel too comfortable. There are also implications for parents concerned about how engrossed their child is becoming in a game, he says.

　　"If a player wants maximum engagement and excitement, we can measure when they are getting bored and, for example, introduce more zombies into the level," McCall said. "We can also control the game for children. If parents are concerned that their children are getting too wrapped up in the game, we can tone it down or remind them that it's time for a healthy break."

　　Of course, biometric controllers are not new. Half-Life studio Valve has tested biofeedback support for a new controller, while one of the PlayStation 4's DualShock 4 prototypes included sensors that detected how much a player would sweat during a game session. No mainstream controller, however, has ever featured any kind of biometric feedback system. It also remains to be seen how expensive biometric controllers are to create.