Biofeedback interaction offers interesting opportunities for video games since it allows player physiological information to be used in novel interaction techniques. Despite several contributions in the area, biofeedback interaction faces a set of challenges relating to its design and implementation. First, it has mainly been used as a method to replace more traditional interaction devices, such as gamepads, mice or keyboards. Also, few of the previous interaction techniques have made an essential use of physiological data: exploring possibilities that could only be developed by involving physiological inputs.

This dissertation explores how different physiological methods, such as electroencephalography, eye tracking, electrocardiography, electrodermal activity, or electromyography, could be used in the design and development of natural user interaction techniques that might be applied to entertainment video games, highlighting technical details for the appropriate use of physiological signals. The research also discusses interaction design principles from a human-computer interaction perspective, evaluates several novel biofeedback interaction techniques with a set of user studies, and proposes ethical considerations for the appropriate exposure to virtual reality and physiological sensor technology.

Results show that the use of biofeedback inputs in novel interaction techniques, vary in complexity and functionality depending on the type of measurements used. They also showed that biofeedback interaction can positively affect player experience since it allows games and virtual reality applications to synchronize with player physiology, making of playing games a personalized experience. Results highlighted that biofeedback interaction can significantly affect player performance, being influenced by the interaction complexity and the reliability of the sensor technology used.