The concept of using your emotional state to alter gameplay is nothing new, but the technology to make that happen has frequently relied on cameras and other special add-ons. Stanford University's Corey McCall has a far more elegant solution -- he recently developed technology that builds skin-based emotion detection into an otherwise ordinary gamepad. The controller changes the intensity of a game based on the feelings you convey through breathing, heart rate and motion. It can boost the difficulty level if you're obviously bored, or tone things down if you're taking a challenge way too seriously. There may not be a great need for McCall's approach when systems like the Xbox One can check your pulse at a glance, but it could let console and peripheral makers offer emotion-aware gaming without requiring cumbersome (or costly) extras.