Physiological computing

So now, the next trend is not tangible! It's intangible instead! According to jennifer Allanson and Stephen H. Fairclough, physiological computing

involves the direct interfacing of human physiology and computer technology, i.e. brain–computer interaction (BCI). The goal of physiological computing is to transform bioelectrical signals from the human nervous system into real-time computer input in order to enhance and enrich the interactive experience. Physiological computing has tremendous potential for interactive innovation but research activities are often disparate and uneven, and fail to reflect the multidisciplinary nature of the topic.

More in this special issue of Interacting with computers. Of course there are already mind games applications like MindBalls released last year. It's a mind-controlled version of Pong. The more relaxed and calm a player's mind, the more the ball moves away from them. Mindball measures EEG or electrical activity in the brain.